a em ALBERT R. MANN LIBRARY AT CORNELL UNIVERSITY CORNELL UNIVERSITY LIBRARY 924 055 099 083 DATE DUE r= — oriOO lOC^ '-^ 9 mt- ■-y DEMCO 38-2< )7 Cornell University Library The original of tliis book is in tine Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924055099083 Ube iRural Ueit=Booft Series Edited by L. H. BAILEY THE CORN CROPS Efje Eural Eext^Booft &evits Lyon and Fippin, Pbinciplks of Soil Man- agement. G. F. Wakren, Elements op Agricbltuee. A. R. Mann, Beginnings in Agriculture. J. F. Duggar, Southern Field Crops. B. M. Duggar, Plant Physiology, with Special Reference to Plant Production. G. F. Warren, Farm Management. M. W. Harper, Animal Husbandry for Schools. E. G. Montgomery, The Corn Crops. H. J. Wheeler, Manures and Fertilizers. (.Frontispiece) TYPICAL PLANTS OF DENT CORN. THE coRi^:;:ia;j'0 ^r fi';>"^'»^ TABLE OF CONTENm/,.r^. PART I CORN CHAPTER I PAGES Production and Distribdtion of Indian Corn . . . 1-11 Relative importance of com and other crops in tlie world, 1 — Corn crop of the world, 3 — International trade in com, 4 — Relative value of different crops in the United States, 6 — • Development of com production in United States, 7 — Production by states, 7 — Production by sec- tions and market movement, 11. SECTION I THE CORN PLANT CHAPTER II Origin and Classification 15-25 Geographical origin, 15 — Biological origin, 16 — Classi- fication of maize in groups, 20. CHAPTER III Description of the Corn Plant ...... 26-37 The root, 26 — The stem, 31 — Tillers, 33 — Leaves, 33 — The flower, 36 — The ear, 37. CHAPTER IV Physiology of Corn 38-56 Turgidity, 39 — Tension, 40 — Mechanical tissue, 40 — The composition of a com plant, 42 — The absorption of water, 45 — The giving off of water, 45 — Assimilation, 47 — Growth, 48 — Reproduction, 49 — Pollen, 50 — Style, 51 — Fertilization, 52. zi xii TABLE OF CONTENTS SECTION II PRODUCTION AS RELATED TO CLIMATE AND SOILS CHAPTER V FAGEB Relation of Climatic Factors to Growth . . . 57-67 Relation of climatic factors to growth, 58 — Length of growing season, 59 — Relation of sunshine to growth, 61 — Relation of rainfall to growth, 64. CHAPTER VI Relation of Soils to Growth 69-73 Causes of low production, 70 — ^Classification of corn soils in the United States according to productiveness, 70. SECTION III IMPROVEMENT AND ADAPTATION OF THE CORN PLANT, AND ENVIRONMENT CHAPTER VII Early CrLTURE 77-84 Development of varieties, 78 — Early methods of modi- .fying varieties, 80 — Natural selection and acclimatization in producing varieties, 83. CHAPTER Vin Improvement op Varieties 85-93 Type of ear, 85 — Type of plant, 86 — Systems of selec- tion, 88 — Results with mass and pedigree selection, 89 — ■ Selection for composition, 91. TABLE OF CONTENTS xiii CHAPTER IX PAGE8 Methods of Laying out a Breeding Plat . . . 94-100 How to conduct a breeding plat, 95 — The second year's work, 98 — Continuation of breeding, several plans, 99. ' CHAPTER X Eesults with Hybridization ...... 101-116 Degrees of Relationship, 101 — Xenia, 103 — Mendel's laws, 104 — Dominant and recessive characters, 105 — ■ Hybridization, eflect on growth, 107 — Self-fertilization, 107^ — Pure strains, orbiotypes, 109 — Crossing biotypes, 111 — Crossing varieties. 111 — Isolating high-yielding biotypes, 115. CHAPTER XI Acclimation and Yield 117-121 Efiect of environment on the corn plant, 118 — Effect of previous environment on yield, 119 — Adaptation of the soil, 121. CHAPTER XII Cropping System in Relation to maintaining the Yield OF CoKN 122-128 Cropping systems, 122 — Restoring production, 123 — Maintaining production, 124 — Rotations for corn grow- ing, 127. CHAPTER XIII Organic Matter 129-134 Farmyard manure for corn, 130. xiv TABLE OF CONTENTS CHAPTER XIV PAGES Mineral Matter 135-150 Fertilizers for com, 138 — Fertilizer mixtures for corn, 142 — When it pays to fertilize for com, 144 — Nitrogen, 146 — Lime, 147. CHAPTER XV Beghlating the Water Supply . . • . . 151-157 Erosion, 154 — Drainage, 167. SECTIOK IV CULTURAL METHODS CHAPTER XVI Preparation and Planting ...... 161-196 The old corn stalks, 161 — Time of plowing, 168 — Depth of plowing, 163 — Subsoiling, 166 — Preparation of plowed land, 166 — Planting the seed, methods, 168 — Sowing corn for forage, 171 — Checking and drilling, ■ 172— Time of planting, 172 — Rate of planting, 176— ' Adjustment of corn plants, 178 — Economic value of tillers, 179 — Rate of planting on different soils, 180 — Methods of distribution of plants, 181 — Width of rows, 182 — Yield of forage, 183 — Effect on composition, 183 — Choice of a variety, 184 — Preparing seed for plant- ing, 190 — Causes of poor germination, 190 — Germina- tion tests, 192 — Importance of strong vitality, 194 — Grading seed, 195 — Calibrating the planter, 195. CHAPTER XVn The Principles of Intbrculture 197-213 Tillage machinery, 197 — Methods of tillage compared, 206 — Water-loss from fallow soil, 207 — Evaporation TABLE OF CONTENTS XV under com crop, 208 — The eflect of weeds, 208 — Depth and frequency of cultivation, 209 — Growing corn for silage, 212. CHAPTER XVIII Animal and Insect Enemies 214-221 Birds, 214 — Rodents, 214 — Insects, 215 — Diseases of com, 220. CHAPTER XIX Harvesting the Cokn Ckop Time of harvesting, 224 — Relative proportion of parts, 226 — Composition of parts, 226 — Relative value of parts, 227 — Time of harvesting for silage, 229 — Meth- ods of harvesting, 230 — "Comparative cost of harvesting methods, 241 — Shrinkage in curing fodder, 243 — Mar- keting, 245. 222-248 CHAPTER XX Uses op Corn 249-252 CHAPTER XXI Show Corn .... Growing show com, 257. 253-258 CHAPTP.R XXII Sweet Corn or Sugar Corn 259-275 Varieties and types, 259 — Varieties, 262 — Seed, 263 — Selecting and curing sweet corn, 264 — Growing sweet corn for canning, 266 — Market sweet com, 270 — Forc- ing sweet com, 273 — Sweet corn in. the home gar- den, 274. xvi TABLE OF CONTENTS PART II SORGHUMS CHAPTER XXin The Sorohum Plant 279-291 Geographical origin, 280 — Botanical classification, 281 — Tiie sorghum plant, 285 — Physiology of sorghums, 286 — Reproduction, 287 — Fertilization , 287 — Natu- ral crossing, 287 — Climate and soils, 288 — Sorghum, types, 290. CHAPTER XXIV The Saccharine Sorghums 293-300 Introduction into the United States, 293 — How the crop is utilized, 296 — Classification of sweet sorghums, 296. CHAPTER XXV The Non-saccharine SoRGHnMs 301-314 Historical, 301 — Ilegion where cultivated, 303 — Sta- tistics of culture, 304— Kafir, 308— Durra, 310 — Shallu, 313— Kowliang, 314. CHAPTER XXVI CuLTORAL Methods for Sorghdms 315-323 Growing sorghums for grain, 315 — Growing sorghums for forage, 321. TABLE OF CONTENTS XVU CHAPTER XXVII PAOBS Utilizing the Sorghum Crop ...... 324-327 Poultry food, 325 — Soiling or green feed, 325 — Pas- ture, 325 — Sorghum mixtures for pasture, 326 — Sor- ghum for silage, 326 — Sorghum poisoning, 327. CHAPTER XXVin SoRGHnM FOR SiRDP-MAKING 328-330 Time of harvesting, 328 — An average yield, 329. CHAPTER XXIX Broom Corn 331-340 Historical, 331 — Statistics of culture, 331 — Varieties, 333— Planting, 336 — Tillage, 336 — Time of harvest- ing, 337. PART I CORN CORN CROPS CHAPTER I PRODUCTION AND DISTRIBUTION OF INDIAN CORN The corn crops, as understood in this book, are the de- rivatives of two group-species : of Zea Mays, the Indian com or maize ; and of Andropogon Sorghum, the sorghum and kafir series. The former is a plant-group of the West- ern Hemisphere and the latter of the Eastern Hemisphere. The maize products are used both for human and stock food, but the sorghum products are employed in this country mostly for the feeding of animals. 1. Relative importance of corn and other crops in the world. — The hay and forage crop is the most important crop of the world, but this is made up of a great variety of plants. The yield in millions of tons of the world's most important plants is shown in the following diagram : — World's Ceops of the Most Impoetant Food Plants. Average FOR 5 Yeabs, 1906-1910 Millions Crop of Ton Potatoes 156 Corn 113 Wheat 107 0|ats 67 Rice 67 Rye 46 Barley 33 CORN CBOP8 m o o O a M o p A o B. - iz; J cs g o M 1— 1 U g ij pq w ..jS ^J ^ go a ^ §1 ^ H 15 O O n o M O K O U ^ o o o o o o o o o o o o h3 P^ T)l to N 0_ U5 00 !^ m" D < lO CX) OS o »-< lO ± 1^ rH lO 00 «D iH cc 1" oT rH t-T to" o" lO" Oi CD lO 00 >-H w 00 lO 1-1 ^ (N m" o o o o o o o o o o o o o o o o o o s oT riT lo" co" eo" <^" C*D lO CD -^ CO CD l> OS »C 00 00 OS H iC TJH CO O i-H CO OS -# 00 OS rt (N O ci -# o o o o o o o o o o o o o_ o_ o_ o_ o_ o O oo"r^-^i> .^'" o" 5^.8SS lO r-( W i-T wf tc lO a:" t> Tti eo 00 X lO I> lO rH U5 (N m" ooooo Q o o o o o o_ s Oi l> CO CO b- cq" r-H C3 t> IN O (N n lO CD IM -* Ol 00 1H r-( OS CO "3 00 00 Tt< cq ^ 00 o 00 lO ^ CD cf CO ooooo ^ ooooo o^ o_ q_ o_ o CO CO i> cq" of o OS xll (M o 1-1 00 lO CD CO '^^ OS T-t H lO OS*" oo" lo" o' »0 00 1> X i-H ^ l> '^ of CO ooooo o ooooo ooooo to o" t-" im" tjT CO 00 -^ CO ^ OS '^_ CO OS lo cq CD ^ i-H od 00 lo os" CO CO O OS 00 CS CO F-H OS CO m" rf • oa ■ • • w o 1 rt a g 5 "J ■ - ■^ <^ ca 03 i 5 Noi Eur Sou Afri Aus Q o o o o o o o o o o o o o o •* CO 01 O 00 ■* 00 (N r- l^ CD lO CO CO X 1-1 CO CO CO rH OS CD IC CO CO 00_ !-(_ 0_ CD_ rf_ O 00_ in OS cq iH lo 00 CD as" c^ O IC lO OS 00 CD iO t* W iH tH cm" o o o o o o rH o CD cq W CO o" o" lo "-T co" o" t-" 00 •^ OS t* O O t* 1:^ 00 cq *-) r-t tH ^ (N" o o o o o o o o o o o o o o o o o o_ o_ o_ o_ o_ o_ q_ o" •^ CD lO os" 00 O 00 OS 00 CD lO 00 CO O OS CO t^*^ iH N ^ o »o IM o cT i> OS o to oa" lO 1-1 t~ t~ OS l> CD CO lO cv< rt rt im" o o o o o o o o o o o o o o o o o_ o_ o_ o_ o_ o_ o_ o_ th" ^~ CD lo CO cq" CD ci" •o lO O lO »0 OS O rH CD CD_ 0_ 0_ OS_ 00 O -H 00 O CD CO »0 00 lO .-T CO OS lO CO OS b» CO CD CO I— t rH I— 1 (n" o o o o o o o o o o o o o o o o o O O O O CD O O o" O CD 00 CO CO O '*' (N cq O CD rH |> O CD CO CO O t- lO >o O IS ." lO o" OS OS .* t^ 00 lO CO »c U5 rt -H o o CM 1-H 1-t e3s OS CO CO t^ °i cq i-l 1-1 rH (M ^_^ flS n a b. V ■ • • ■ o CoUNTH United Stat Austria- Hungary Mexico Argentina Italy . . Roumania Egypt Russia (Eur PRODUCTION OP INDIAN COBN 3 In total value, the world's wheat crop probably ranks first, the potato crop second, and the corn crop third. 2. Corn crop of the world. — The following tables (I, II) give the world's production of corn for the past five years. The data is abstracted from the Year Books of the United States Department of Agriculture : — TABLE II Percentage of World's Corn Grop produced by the Con- tinents, AND Principal Corn-producing Countries. For 5 Years, 1906-1910 Continent 1906 1907 190S 1909 1910 AVEBAGE North America Europe . . South America Africa . . . Australia . . 77.25 15.34 5.03 2.15 .23 80.56 14.34 2.29 2.49 .32 78.74 14.68 3.98 2.36 .24 77.06 16.04 5.20 2.42 .28 76.88 16.02 4.55 2.25 .29 78.09 15.08 4.20 2.35 .28 Total . 100.00 100.00 100.00 100.00 100.00 100.00 Principal Countries United States 73.85 76.79 73.94 71.74 71.67 73.39 Austria- Hungary 5.31 6.74 5.28 5.92 5.97 5.64 Mexico . . 2.77 4.09 4.16 4.77 4.73 4.10 Argentina 4.91 2.09 3.77 4.98 4.35 4.02 Italy . . . 2.34 2.58 2.65 2.79 2.62 2.57 Boumania 3.29 1.68 2.18 1.97 2.57 2.34 Egypt . . . 1.64 1.90 1.80 1.82 1.74 1.78 Russia (European) 1.77 1.48 1.69 1.11 1.91 1.59 Total . . 95.88 96.36 95.46 96.10 96.46 95.43 The world's corn crop varies from about three and one- half billion bushels to about four bilUon bushels, or a variation of 12 per cent. This rather wide variation is CORN CROPS due to the fact that more than one-half the world's corn crop is concentrated in one section of the United States. The comparative production is brought out more clearly in Table II, based on percentage production. From the tables, it appears that North America pro- duces 78 per cent of the world's corn crop, Europe pro- duces 15 per cent, leaving only 7 per cent for the other continents. The United States produces about 73 per cent of the world's crop, Austria-Hungary 5.6 per cent, Mexico 4.1 per cent, and Argentina 4 per cent, the four countries combined producing 87 per cent of the world's crop. TABLE III Showing Coen exported by Countries and Percentage OP Total World's Exports for 5 Years, 1906-1910, Inclusive CotTNTET AvEKAQE Annual Export BUBHELS Pebcentaqe of Total Exports Argentina United States .... Roumania Russia (European) . . Belgium Netherlands Bulgaria Servia Austria-Hungary . . . Uruguay Other Countries . . . 83,569,388 62,596,444.2 33,124,210.4 23,255,489.2 7,007,737.8 6,718,712 6,021,984.4 3,054,136.2 328,352.6 . 210,674.2 8,703,035 35.66 26.64 14.15 9.90 2.93 2.83 2.55 1.35 .14 .09 3.75 Total 234,590,164.0 100.00 3. International trade in corn. — The net exports and imports indicate those countries producing a surplus, and those countries an well that must buy. Table III shows PROJDUCTIOSr OF INDIAN CORN' that Argentina furnishes about 35 per cent of the world's export corn and the United States only 26 per cent. Table IV shows that Argentina exports 55 per cent of the crop produced, while the United States exports only 2.29 per cent. This country can hardly be. classed as a sur- plus corn country, though the small percentage exported furnishes one-fourth of the world's export com, The prin- cipal importing country is the United Kingdom, taking 36 per cent of the world's trade in corn, and Germany 14 per cent more, the two taking one-half the corn trade. TABLE IV Showing Percentage of Total Corn Crop exported by THE Principal Exporting Countries, 5-Year Average, 1906-1910, Inclusive COTJNTHT PKODtrc?rioN m Bushels Exportation in Bushels Percentage op Ckop United States . . Argentina . . . European Russia . Roumania . . . Bulgaria .... 2,725,367,400 151,015,000 69,831,200 88,163,400 22,281,800 62,596,444 83,569,388 23,255,489 33,124,210 6,021,984 2.29 55.33 38.86 37.57 27.02 Europe consumes about 91 per cent of the world's corn trade. This com is largely used for feeding live-stock, but also in the brewing industry. Exportation of com from the United States is decreasing. The maximum exportation from this country was during the 5-year period 1896-1900, when it reached an annual average of 9.4 per cent. The present decrease in expor- tation, indicates that home consumption in the United States will soon equal production. In fact, in the past three years corn has been imported on the Pacific Coast. CORN CROPS TABLE V Showing Corn imported by Countries and Percentage of Total World's Imports for 5 Years, 1906-1910, In- clusive CODNTKT Av. Annual Import op COHN IN Bn. FOB 5 Yr. Percentage of Total Import United Kingdom . . . Germany Netherland Belgium France Denmark ... Canada Italy Spain Austria^Hungary . . . Switzerland Mexico Cuba Portugal Norway Egypt Sweden Russia British South Africa . . Other Countries . . . 84,835,078 34,189,007 24,836,943.4 21,984,982.6 13,510,287.2 12,705,123.8 10,809,151.8 7,737,137.8 4,891,501 4,170,578.2 2,996,767.6 2,738,086.8 2,546,576.8 1,169,913.4 1,043,998 662,416.4 386,611 329,755.6 147,452.2 3,453,661.4 36.07 14.53 10.56 9.36 5.74 5.45 4.59 3.29 2.08 1.77 1.27 1.16 1.08 .49 .44 .28 .16 .14 .06 1.46 Total 235,145,030.0 100.00 COEN PRODUCTION IN THE UNITED STATES 4. Relative value of different crops in the United States. — The corn crop is more valuable than any two other crops in the United States. The value of all wealth produced on farms, including that derived from cereals, hay, cotton, live-stock, forests, and fruit, amounts to 7955 millions of dollars. The corn crop alone furnishes about one-fifth of this annual wealth. PRODUCTION OF INDIAN CORN Relative Fakm Value op Principal Crops in the United States. Average for 5 Years, 1906-1910 Value in Crop Mmiona Com $1431 Hay 681 Cotton 670 Wheat 590 Oats 367 Potatoes 187 Barley 92 Tobacco 82 5. Development of corn production in United States is shown in the following table : — TABLE VI Average Production op Corn at Different Periods Yeahs ACBGS BUSHSLS (000 omitted) Yield PEB Acre Bushels Total Value (000 omitted) Value per Bushel 1849 . . 1859 . . 1867-1876 1877-1886 1887-1896 1897-1906 38,688,449 68,408,900 74,290,879 87,971,235 592,071 838,793 1,011,535 1,575,626 1,800,271 2,240,363 26.2 25.1 24.0 25.4 Dollars 457,000 625,623 633,694 869,575 Cents 46.5 40.3 36.6 39.0 The total crop has about doubled in 40 years and quadrupled in 60 years. 6. Production by states. — Table VII gives the most important data summarized on the production of com by states. This table is arranged according to rank by states and shows that the eight leading states produced about 63 per cent of the total crop. COBN CROPS 1 1 M Per Cent SHIPPED OtJT OF County whekb grown ,^gS^SS«'?5?32^^g?S*'«^^2=^^ i-H 02 S Ph 11] S a coaiioooc»3iN0500-*'-iiOi-io>^05oocooooiaioo 'Average Yield per Acre Bushels O fl o P 1 ooo>nr-(ooooooo5t^oioo-*oco>-Hi>Nrt .-lO'-HOOiOOt>i-lOCOT-IO(N"3tOI>(M-*C<3(Nt^ O-*t^T-lOO00O-*C0C«5-*>0'-iC0t0CClOrtl00> CO o to" to" to" to" ■*" (m" ■*" (N o" t>" to" o" in" ^ ro" n" ■*" ■*" ■*" '^tDOOO.-l(N03-*03'*Mi-lOCX303tD'-lt~eOlOtO NNtomtocO'-^r)<^-*_ooooioinoOi-H-*Oi-<_c»io o "O t-^ ■4' of >n" ^-" t-h" o o t~ "-h" 03 lo (N i>" oj" o c> in" co" tOC<3000I>r^OOI>iOU5-*C<3IMCaimcD05(Nt^-* l>000"nOCOO'-H.-liOOOrtiOl^f-l>(Ni-ltO to" lo th" rH to in CO o" (N of ^•^ r-T ,-4" c<5 CO CO to o ffl" •* rt |>t^O(^^T-^xc^^co^o»noiotOlOc^^*oc^^oooot^ t~_(N Th'*l>lO_00_tO_O CO -Hr-.^ 03. !>■*'* O ^ 00 00 to of of i> i>" -*" t> to" CO lo" CO co" i-T i-T r-T i-T t-h" tjT of i-T eq" in" o o K < a o 2 1 a t^OOOCOOtOOOOlOOOOmOtDOiCO'^QOOi '-igooino>nO'-it^oooin-*-*T-H,-iot^tD °l"^'^_'^-''i'^'^'°"^^<*Ot>00(Ni-HCOlOI>INI> t;:^ n" 1-^" ui" Q CO Tin" N in CO N o •^" 00 to" to N i> t> in Qo" oo;c2r-H^gtpoincoiM-*-*coino'*-*0'-Ht- O3(N-^COO3(Nt^tDi-ltOt^00i— lOC^OOiOOSi-lO COC0IN(Nt-It-(,— IrH^H (NrtOOTl(I>OOINCOrH-*fOMrHO {NlOCqOSK^P'-HNi-HN-^OqiOrHTHN'-jTtHMQqO'-lOSlOINO ^o^-^rH(^iI>,4•5t^do^■-^cvi^orticd.-H,-^MlOlOc^^co^^oodcviQd <-lr-lr-(CO(NC<3COi-l'*O OOi-H-^OiOMNOOi-ltOiOTtlNOi-ICTOOOOINi-IINOSOOOiOO 00 CO 00 M rH p U5 U5 ^_ lO (N (N CD N TO O t~ p Ca 05 O ■* (» >H U5 -^^ CO ^^ N CO M (n" co" CO CO ■*" co th" rH CO ^^ iO(NlOC0COI>Oi-l00C0-*i-l(NcD03C0i-lC0-*-*i-l-*Oii:i>Ot^(M (NpcOCONpNpp>opi>-5HcO_COlOI>Ttlcv5COCOCONT-(T--l O O (N IM" ■*" ■* CO lO N Im" (N~ i-T i-T i-T 1-H N CO (N IM i-H i-H ^ ■*CD050500aiO'*rt0050005r-(r-(t^OCDOO(Mecoo^ojiococo-*t>i-ioooo3C p^ CO i-T i-T i-T o (n" CO "-T co" lo im" lo" c i> lO i-T IM" rH W rHC0C0l0OOt>O(NI>OOC0-*(N>ncO t^'cO rH O TH(NTHCOOOiOOCOINOCDiOOOCD(NmaSi-II>l>(MOO(MlOO p rH 00 in (N oq_ (N o_ oq_ oq^ ■* p n io_ p oq_ t> i> p rH* CO" QO" CO !> I> lo" OO" ^ >0 I> N (35 OJ" OO" CO l> 00 (N CO (N I> C0C0rH00lOt>OC0Q0(N05OrHinrH N.OO l>iOlOt^-*CO(NOOO(N rH(MOt>CO(NOOrHCOOt>-*OOOI> O 03 lOTlH-^COCONINrHrH IN rH t>" rH o" O" Os" l> lO" ■*" CO" IN" (N r^ rH ■* Th CO (M (N (M Abbe, loe. cit., p. 85. ' Ibid., p. 92. 64 CORN CROPS TABLE XII JATITUDB Month 0° 10° 30° 50° 70° 80° 90° March 20-31 . . 3.7 3.7 3.3 2.3 1.1 0.6 0.2 April 10.0 10.6 10.1 8.0 5.4 3.9 3.4 May 9.8 10.7 11.7 10.5 9.0 8.6 8.7 June .... 9.2 10.4 11.9 11.3 10.7 11.0 11.1 July 9.7 10.7 12.1 11.3 10.3 10.1 10.2 August .... 10.1 10.7 10.9 9.2 6.8 5.9 5.8 September 1-23 . 7.7 7.8 7.1 5.2 2.7 1.5 0.9 Total .... 60.2 64.6 67.1 57.8 46.0 41.6 40.3 Total possible if sun stood at zenith . . . 186.0 186.0 186.0 186.0 186.0 186.0 186.0 It is apparent from the above data that up to 70 degrees north latitude there is sufficient sunshine during the summer months to 'produce corn, were it not for other hmiting factors, as low temperature due to a cold soil and cold air currents. The data presented thus far are on the basis of per- fectly clear days, but the presence of clouds reduces the sunshine. At Montsoris, France, careful records for the corn-growing season kept from 1875 to 1885 showed only about 40 per cent of the possible intensity of sunshine, due to cloudiness. Corn under such conditions does not grow well, but requires, even at that latitude, what might be termed a rather " sunny " climate. We may conclude that except where cloudiness prevails for half the time, there is sufficient sunshine for corn pro- duction even up to 70 degrees latitude. 50. Relation of rainfall to growth. — The transpiration of 14 to 20 tons of water is required to produce one bushel CLIMATIC FACTOBS 65 of corn. For a yield of 50 bushels per acre, this equals 7 to 10 acre-inches of water.^ With a larger crop the water used would be increased proportionally. Under field condi- tions there must be added to this whatever loss may take place through run-off, evaporation from the soil, and seepage. King found that a yield of 7000 to 8000 pounds Fig. 24. — Chart showing relation between storage water in the soil and consumption of water by the corn plant each month. The storage capacity of the soil is exhausted before the end of July. The crop is therefore dependent on July and August rainfall. of dry matter per acre (approximately a 50-bushel jaeld) required about 12 acre-inches under field conditions. In this case the loss by seepage, run-off, and evaporation must have been about 5 acre-inches (assuming 7 inches used by the crop), but this will vary with the soil, culti- vation, distribution of rainfall during the growing season, and amoimt of storage water in the soil at planting time. 1 Montgomery, E. G. Ann. Rpt. Nebr. Agr. Exp. Sta. 1901 ; 155. King, F. H. Abu. Rpt. Wis. Agr. Exp. Sta. 1902 : 99. F 66 COBN CHOPS An average corn soil in good tilth will store about 5 to 6 inches of available water in the upper 4 feet. A 50- bushel crop would then require at least 6 inches addi- tional rainfall during the growing season, and prob- ably more than this, as corn seldom grows well when required to exhaust the soil moisture to low limits. A 75-bushel crop would require an additional rainfall of 10 inches and a 100-bushel crop at least 15 inches during the growing season, in addition to that stored in the soil. When the run-off is large, as on hills or with torrential rains, or when there is seepage, the above estimate should be increased. This estimate is on the assumption that the soil is fertile. No amount of rain would make a poor soil productive. For example, the average rainfall for June, July, and August in the eight surplus corn States is about 12 inches, but the average yield is 28.5 bushels. Other factors than total rainfall here limit the yield, one important factor being that the rainfall is not always properly distributed. 51. Any system of cultm-e that will serve to prevent run-off on the one hand and to decrease evaporation on the other, will proportionally increase the available water supply for the crop. Not only the total amount, but the distribution, of the season's rainfall is of great importance. Figure 25 shows the precipitation for June, July, and August for a period of fifteen years and the yield for eight surplus corn States, namely, Ohio, Indiana, Illinois, Iowa, Nebraska, Kansas, Missouri, and Kentucky.' Here is shown a very close relationship between rainfall and yield, when large areas are considered. 1 Smith, J. Wareen. Relation of Precipitation to Yield of Corn. U. S. Dept. Agr. Year Book, 1903 : 215-224, CLIMATIC FACTORS 67 Professor Hunt/ at the Illinois Agricultural Experiment Station, grew 18 plats of corn which yielded 32 bushels per acre. The next year, and on the same plats and with the same varieties of corn, the yield was 94 bushels per acre. The rainfall from May to September was 13 inches the first season and 22.5 inches the second season. i I 34 32 30 OB 1 a 1 14 13 12 11 10 9 8 7 6 r ; / { ,' \ \ /' \ y^ ■J ''■-. \ \ 1 \ ./. •' i ;7 •Jg V \ t s^ ' A' ,' \ ;/ •>! /; \ ;7 22 m \ \ /,' \ \\ 'j \ 18 ' cooOi-fcqco'^iocot^QoaiO^tM OOOOOOSOSOOSOiOiOSOSOaOOO COCOCOOOOOXQOQOOOOOOOXOiOSOS Fig. 25. — Rainfall of June, July, and August, and yield of corn per acre. (Year Book, U.S. Dept. Agr., 1903.) Average yields of corn 1888 to 1902. Average rainfall for June, July, and August. The seasonal rainfall and its distribution is the most important climatic factor in corn production. With suffi- cient rainfall, properly distributed, it is probable that the present 3deld of corn would be increased 50 to 100 per cent. We cannot control the rainfall or its distribution during the season, therefore farm practice must make the best use of rainfall as it comes. The present rainfall is suffi- cient for two to three times the present yield, if it is con- served and the soil is in the most fertile condition. ' Hunt, T. F. Cereals in America, p. 207. CHAPTER VI RELATION OF SOILS TO GROWTH Most of the good corn soils of the United States are deep black loams, well drained, well supplied with organic matter, and rich in available nitrogen, phosphates, and potassium. 52. The soil may be regarded as a medium for holding minerals and water in an available form for the plants as needed. Natural productive soils are those that in a state of nature contain all the mineral elements and organic matter necessary, and are supplied with sufficient natural rainfall. In some virgin soils, as the deep black loam soils of the Mississippi, Ohio, and Missouri river drainage basins, there is sufficient of all mineral elements in an available form for the maximum production of corn. Even in these soils, however, maximum production is seldom at- tained, as the rainfall is not always properly distributed, nor even sufficient. Corn especially enjoys a large supply of nitrogen and will flourish in soils so rich in available nitrogen that other cereal crops would produce an excessive amount of straw, probably lodging and making a poor yield of grain. Corn is able to make use of fertility furnished through the de- caying of coarse organic matter, as manure or sod land ; while other cereals, as wheat and oats, require for best results a more advanced state of decomposition, with the elements more easily available. 68 RELATION OF SOILS TO GROWTH 69 The ability of corn to utilize to advantage large quan- tities of fertilizer and manure is illustrated in the cases cited on page 57 of the four maximum yields of corn produced. Fig. 26. — Corn as it grows on the best type of natural corn land. 70 COBN CROPS CAUSES OF LOW PRODUCTION 53. Assuming rainfall to be sufficient, a good corn soil should produce 75 bushels per acre. Only a small per- centage of the corn land in the United States will yield this at present, due to certain causes which may be summarized as follows : — 1. Poor drainage. Corn suffers more than do other cereals from poor drainage, as it requires a " warm " soil, and also available nitrogen in rather large quantities. Nitrifying processes are hindered in waterlogged soils. 2. Surface soil depleted through erosion, very com- mon on rolling lands in regions of large rainfall. 3. Soil once fertile but depleted through constant crop- ping without return of organic matter or minerals. 4. Soils which in a virgin state were deficient in organic matter or lacking in some mineral element. Each of the above soils will be found deficient in one or more of the following : — (a) Drainage. (b) Organic matter. (c) Nitrogen. (d) One or more mineral elements. (a) is corrected by drainage, (6) and (c) by manure or the growing of legumes, (d) by manure or commercial fertilizers. CLASSIFICATION OF CORN SOILS IN THE UNITED STATES ACCORDING TO PRODUCTIVENESS 54. For the regions east of the Rocky Mountains the corn soils may be classed according to productivity into four general groups. 1. Soils capable of producing 75 bushels or more per RELATION OF SOILS TO GROWTH 71 acre, with normal rainfall of region such as the black loam bottom land soils of the Mississippi drainage basin, and certain areas of black upland or drained swamps. This soil is well drained, well supplied with organic mat- ter, minerals, and rainfall, and usually commercial fertil- izers will show little or no effect. The total area is small, probably not greater than 1 per cent of the Corn Belt. This may be termed the ideal corn soil. 2. Soils producing 35 to 50 bushels per acre, with favor- able climatic conditions. (a) This includes the greater part of the cultivated lands in the surplus corn States of Ohio, Indiana, IIU- nois, Iowa, Nebraska, Kansas, and Missouri. These soils have been cropped for fifty to seventy-five years, during which time the ability to yield has decreased 25 to 50 per cent. All these soils respond quickly to an application of manure, or are increased 25 to 50 per cent in productivity by growing a crop of clover or alfalfa. They seem to need organic matter and available nitrogen more than anything else. The supply of minerals is gen- erally sufficient, but in many cases the application of both potassium and phosphates gives increased yields, though, as a general rule, the increase is not sufficient to be profit- able. Rotation, the use of legumes, and manure are to be relied on at present as the principal means of main- taining or increasing the yield. (6) All the " good corn land " through the Eastern and Southern States is also included in this class. 3. Land producing 25 to 35 bushels under favorable climatic conditions. (a) Through the Eastern and Southern States are large areas which are fairly productive when first brought under cultivation, but which have been cropped for 72 CORN CHOPS seventy-five years or more. Erosion also has played an important part in depleting the rolling lands. The supply of organic matter is generally low, and in many cases the lands need under drainage. Throughout the " Corn Belt " there are also considerable areas in this class. (6) Soils naturally not very productive, through lack of one or more mineral elements or of drainage. In general, legumes and manure must be the principal means of increasing and maintaining the productivity of this land; but when a mineral element is lacking, as lime, potassium, or phosphorus, it will usually be neces- sary to add this in the form of commercial fertilizer. 4. Land producing less than 20 bushels per acre. (a) Through the Eastern and Southern States are large areas which, through continuous cropping and erosion, are low in yield. In addition to the prevention of ero- sion, the same general treatment as is recommended for the previous class may be used. (6) Land in regions of deficient rainfall! Where there is less than eight inches during the growing season, lack of moisture becomes a limiting factor in corn production. From Dakota to Texas there is a large area with a fertile soil but an annual rainfall of only 18 to 25 inches. In these soils conservation of moisture is the most important phase of soil treatment. SUMMARY 55. The ability of corn to yield is indicated by certain maximum yields, when 150 to 200 bushels per acre have been harvested. Regarding climatic factors, there is usually enough sunshine and, in most of the Corn Belt, a sufficient total rainfall ; but the latter is not often dis- RELATION OF SOILS TO GROWTH 73 tributed in the best way for the growth of corn. A large share is lost by run-off, and the supply is seldom properly conserved by preparation of the land and by cultivation. The length of growing season is a limiting factor, where the season is less than 180 days. The principal cause of low production is lack of avail- able fertility in the soil. Climatic factors are mostly out of our control except that the effect of rainfall may be modified, hence our principal efforts in increasing corn production should be in the treatment of soil. SECTION III IMPROVEMENT AND ADAPTATION OF THE CORN PLANT, AND ENVIRONMENT CHAPTER VII EARLY CULTURE OF CORN Indian corn was unknown to Europeans until the discovery of America. At that time it was found tq be in general cultivation by the Indians of both North and South America. In fact, corn was the principal crop cultivated by the native Americans, as they had neither oats, wheat, nor barley, and very few of the cultivated vegetables. The most ancient evidence of the culture of corn is found on the western coast of South America and in Mexico. In Peru specimens of corn have been found in connection with ancient ruins or geological forma- tions, which are probably at least two or three thousand years old. The f 3,ct that corn was buried in the tombs, as well as other evidence, indicates that it had an important place in the religious ceremonies of this semicivilized people and was probably their most important cultivated plant. 56. During the fifteenth century the earliest white ex- plorers of America took corn back to Europe, where in time it came to be extensively cultivated, especially in those countries surrounding the Mediterranean Sea. When corn culture began to spread in Europe it had many curious names, as Italian corn, Turkish corn, Spanish wheat, Guinea wheat, and others, probably indi- cating the places where its culture first became extensive. Collins has recently described a type of corn cultivated 77 ^ 78 CORN CROPS in China. References to com in Chinese literature indi- cate its culture in China for some 350 years, although just how or when corn was introduced into China is a question. When the first white, settlers came to America, at Jamestown (1607) and Plymouth (1620), they at once took up the culture of corn, procuring the seed and learning the method of culture from Indians. It soon became the most important cereal crop of the colonists, gaining its popularity by reason of its simple culture, its sure produc- tion, and the ease with which the crop was harvested and preserved. DEVELOPMENT OF VAKIETIES 57. In 1898 Sturtevant listed 507 named varieties and 163 synonyms. It was not possible for Sturtevant to secure all varieties in his day, and it is probable that a complete catalogue of all varieties at present would almost double this number. Of these varieties listed by Sturtevant, 323 were classified as dent corn, 69 as flint corn, 63 as sweet corn, 27 as soft corn, and 25 as pop corn. It is known that at least a few varieties of all the five principal groups were in cultivation when America was discovered, with the possible exception of sweet corn. The earliest record we have of sweet corn is in 1779, when it was mentioned as being in cultivation near Plymouth, Mass.i However, it could easily have been overlooked by the early explorers and has probably been in existence for a long period. It appears that the Indians inhabiting what is now the northern part of the United States and southern Canada iStubtevant, E. L. U. S. Dept. Agr., Office of Exp. Sta., Bui. 67 : 18. EARLY CULTURE OF CORN 79 cultivated mostly an eight-rowed flint corn, and in a limited way an early variety of soft corn commonly known to-day as " squaw " corn. The Indians of the south- western United States, Mexico, and South America cul- tivated the different varieties of soft corn principally, and also, in a limited way, flint corn, pop corn, and dent corn. The dent corn, however, does not appear to be like our modern dent of the deep-grained, large-eared varieties, such as Boone County White, but of a rather shallow- grained type with a square grain or a grain even broader than long. There was also a very rough, deep-grained type with a short ear, similar to our Shoe Peg corn of the present day. By the year 1800 there were a number of recognized varieties of flint corn, mostly of eight-rowed types, and a few dent and soft corns cultivated by the colonists. At least one variety of sweet corn (the Papoon eight- rowed) and a few pop corns were known, but were not in general cultivation. Bonafous, in 1836, and Metzger, in 1841, both published classifications and descriptions of corn indicating that at least all the characters of corn known at present were to be found among the varieties at that time. Metzger made twelve races, and mentioned varieties ranging in height from 18 inches to 18 feet. Since 1840 there has been a rapid expansion of corn culture and great interest has been shown in the development of varieties adapted to various conditions and uses. It may be safely estimated that perhaps three-fourths of the present varieties of corn have been developed since 1840. The history of sweet corn is an excellent example. Following are listed the authorities and the number of varieties of sweet corn that each knew, and the year of his observation : — 80 COUN CROPS Date AUTHOBITY Number of Varieties 1779 1832 1836 1853 1858 1866 1884 1898 Bridgman .... Bonafous U. S. Patent Office Rpt. Ellippert . . : . . Burr Sturtevant .... Sturtevant .... 1 1 1 3 6 12 33 63 There has been a similar rapid development of dent varieties. In 1866 Edward Enfield ^ made a list and description of corn varieties, which he said represented " most of the varieties in use, and all that are likely to be of practical value to the farmer." Of field corns he describes 20 varieties, 13 of which were flints, 3 broad-grained dents of 12 or 14 rows, 1 flour corn, and 3 gourd seed varieties grown in the South. However, J. S. Leaming had begun selecting " Leaming " corn in 1826 and Mr. Reid began selecting his corn in the late forties. With the rapid de- velopment of corn culture, after the Civil War, the modern dent type came to be generally used throughout the Corn Belt States ; although the flint corns are still the principal corns in the Northern States, where the season is too short for the large dents. 58. Early methods of modifying varieties. — Probably the means that has been most commonly used in the past was either to hybridize two varieties and select some type from this hybrid for several years until the type was fixed, 1 Enfield, Edwabd. (1866.) Indian Corn. D. Appleton & Co., New York. EARLY CULTURE OF CORN 81 or to start a systematic selection in some recognized variety. One of the earliest reports of the origin of a variety is given by Mr. C. H. Heydrick, of Utica, Penn., in the Agri- cultural Report of tlje Commissioner of Patents for 1853. As most . early varieties were originated by some such method, the quotation is here given : — "Witli regard to the changes which may be wrought in a variety by cultivation, I cannot give a better illustration than the history of the ' Vermont YeUow,' that I cultivated a few years ago. Its characteristics were, a short stalk, slender above the ear, strong below, ears small, with eight rows, thick at the butt end, growing near the ground, and frequently having a stem two feet in length. My plan of selecting seed from this variety was to choose from such stalks as produced two or more ears, reject- ing those with large butt ends, and such as were not set close to the stalk. Such seed was hard to find the first year. The second year nearly one-half of the stalks produced two ears, and there were fewer long stems and large butt ends. A milder climate had also produced another change. Many ears appeared with ten or twelve rows. This induced me to improve the size of the corn and accordingly I selected as before, adding such ears as contained more than eight rows, together with a few ears of a larger sort. Continuing this system for a few years I ob- tained a variety characterized by the following marks : stalks light, seldom exceeding six feet in height ; strong below the ears, slender above ; ears containing from ten to fourteen rows, and from two to three ears to a stalk, more frequently than a less num- ber. From these facts it will be seen that a mixed variety may be produced, possessing all the desirable qualities of several old ones. But such a new variety will require attention a few years, to prevent it from degenerating into one of the original sorts, after which, I think, the variety will become as permanent as any other." Many of the early corn breeders used the above method of selecting out some type from an old variety. It is probable, however, that many of the variations found a 82 CORN CROPS were due to natural hybridization, as this is likely to take place to some extent in a neighborhood where any two fields are less than twenty to forty rods distant from each other. Fig. 27. — Relation of type to climate. The short type on left is better adapted to dry regions than the tall, more slender type. The tall type is adapted to warm, more humid regions. Crossing as a means of securing new forms was often practiced, and a method is outlined by Enfield (1866) .^ 1 Enfield, Edwakd. (1866.) Indian Corn, pp. 70-74. EARLY CULTURE OF CORN 83 59. Natural selection and acclimatization in producing varieties. — It is well known that each region of the United States has corn of a type more or less peculiar to that section. For example, in the Gulf States, corn grows very tall, frequently 15 to 18 feet, with ears 6 or 8 feet from the ground; in the Corn Belt States the plant is about two-thirds as high ; while along the Canadian border the height is 5 to 8 feet, and ears are often less than 2 feet from the ground. Also the growing season will vary from 200 days in the South to 80 days in the North. If a variety of corn be moved from one section to another, it will become from year to year more like the native corn of the region. It is not known how much of this change may be due to actual modification of the plant by environment, but it is probable that it is brought about chiefly through wide variations and through both natural and artificial selection. When a variety is moved from one climate or soil to another, it does not yield so well the first year as later, when it becomes "acclimatized." When planted first in the new location, there are certain plants much better suited than others to the new conditions. These would produce the best ears and be selected for seed, thus preserving the best-adapted type. An excellent example is cited from Nebraska,' where a variety of com from Iowa was grown in central Nebraska for two years and as a result decreased about 12 inches in height, while the ear was almost 8 inches lower; the yield of grain, how- ever, increased. If the same variety be widely distributed and grown for a few years, and seed again collected for compari- son under the same conditions, it will be found that 1 Nebr. Agr. Expr. Sta., Bui. 91 : 29, 84 CORN CROPS each region has had some effect in modifying the original type. SUMMARY 60. The early culture of corn probably originated in the high plateau 'region of southern Mexico, about the beginning of the Christian Era. From here it spread north and south, its culture being general throughout North and South America by the year 1000 a.d. The Indians grew flint and flour corns chiefly, probably because of their keeping and germinating qualities. Most of the modern varieties in general use in North America have been developed during the past century, though the principal types have probably been in existence for many hundred years. Selection, both artificial and natural, accounts for the origin of many varieties; while crossing, sometimes in- tentional, but often accidental, has furnished a great many variations from which to choose. References on early culture : — See, References on early Mstory ; p. 24. References on origin of varieties : — Mo. Agr. Exp. Sta., Bui. 87 : 113. Nebr. Agr. Exp. Sta., Bui. 8S : 12. V. S. Dept. Agr. Yearbook, 1907 : 331. Bowman and Cbosslt. Corn, p. 424. CHAPTER VIII IMPROVEMENT OF VARIETIES Perhaps no other cultivated plant in America has been the object of so much study and attention, with the object of adapting it to the various soils, climates, and needs of man, as the corn plant. The plant is large, interesting, lends itself well to de- tailed study, and responds readily to care or selection. From earliest domestication by white men, there has always been a large number of growers, giving time and attention to its improvement. An infinite variety of forms has been developed. Every detail of the plant has been studied as to its possible economic value, in improv- ing the yield or quality of grain or forage. Almost every possible theory has been held by practical growers regard- ing the relative value of different types of ear, leaf, stem, or other parts of the plant. Of recent years, good scien- tific study has also been made at many of the experiment stations. In the following pages it is attempted to sum up what is known to be of practical value in type of plant or selection of methods. 61. Type of ear. — From the earliest times it is probable that some attention has been given to the types of ear selected for seed. The originators of varieties have usually had a well-defined type in mind, for which they have selected. There is no evidence that the type of ear chosen has had a direct relation to yield, since equally good 85 86 CORN CROPS results have been secured with very diverse types, as the tapering Learning, the cyhndrical Reid's Yellow Dent, the shallow Hickory King, and the extremely deep- grained Hackberry. Flint corns and the small-eared, prolific corns have also given excellent results. Since several investigators have studied ear characters in relation to yield, all data verify the experience of Hartley, which he summarizes as follows : "A careful tabulation of yields as compared with other ear characters, covering six years' work with four varieties, embracing in all more than 1000 ear-to-row tests of production, in- dicates that no visible characters of apparently good seed ears are indicative of high yielding power." Since white men began corn culture, no doubt some gain has been made in ability to yield, but the fact that large ears have been selected will account for this. As the ear represents the producing ability of a plant, all other things being equal, the selection of large ears would preserve the most productive strains. Varieties having a medium depth of grain mature better and keep better in the crib than very deep-grained types, and, since they seem to yield as well, they are to be preferred. 62. Type of plant. — ■ While some study has been given to the character of plant, no definite relationship has been proved, which would justify the consideration of the plant in seed selection, other than this : the average type in an acclimated variety will yield better than either extreme. The average type, however, varies in different regions. For example, on the west edge of the Corn Belt, with a rainfall of 22 to 25 inches (central Nebraska, Kansas, and vicinity), the plant when acclimated is short, stocky, with the ear rather low. To select here for tall plants IMPROVEMENT OF VARIETIES 87 with the ear borne high would not be in harmony with natural conditions, and experience has shown that varieties having these characters do not yield so well as the native type. Also, at the Nebraska station, when comparison was made between broad-leaved and narrow-leaved strains in dry years, there being an excess of sunshine and hmited water supply, the largest yields were obtained from narrow-leaved strains.^ In one year, with excessive rain- fall, broad-leaved tjrpes gave larger yields. While broad leaves elaborate starch, they also evaporate water at a rapid rate ; hence, the most desirable leaf area on corn plants must be a balance between the moisture supply on the one hand and sunshine on the other. While under rather abnormal conditions for growth, as a dry climate, attention must be given to the character of plant growth, yet under normal conditions a wide range is permitted. In Illinois, where selection for height of ear was continued for six years, there was no marked difference in yield between the high-ear and low-ear types, and the same was also true when angle of ear was considered. It may be assumed that when selection is made for yield, all other characters of the plant will adjust them- selves under the given conditions ; so that ultimately the type of plant giving best yield under those conditions will result. However, under certain conditions in the South the ears are borne very high, and in the North, in some cases, the ears are borne very low. In both these cases, for convenience in harvesting, it would be well to select for a more desirable height of ear. There are many in- stances where selection to modify some character of the plant would be justified, even though the yield was not affected. » Nebr. Agr. Exp. Sta., 24th Ann. Rpt., p. 158. 88 CORN CROPS SYSTEMS OF SELECTION 63. Mass Selection in corn is the method of selecting from a large field a number of individuals that conform nearest to some ideal type. Seed of these plants is mixed together and planted a second year and again a large number of ears are selected and mixed for planting an- other year, and so on for many years. It was discovered, however, that of two ears much alike in appearance, perhaps one might yield 25 per cent to 50 per cent more than the other when used as seed corn. The importance of testing each ear separately was- at once recognized. In pedigree selection after the first mother ears are selected, a separate record is kept on the performance of each ear or its progeny. For example, if it is desired to select for a type bearing ears low on the stalk, a hundred such ears might be selected from a large field. If mass selection is practiced, they are mixed together and planted the following year and the method continued for several years. If pedigree selection is followed, each ear is planted in a separate row and a record made of the percentage of low ears produced by each mother ear. Seed ears are only saved from those mother ears producing a large percentage of low ears, the remainder being discarded. Perhaps ten mother ears out of the first 100 will be found to transmit the desired quality. From the progeny of these ten ears, 100 ears may again be saved, each to be planted in a separate row. This may be continued for several years, the performance record being kept for every year. By keeping a record on each family separate it will be possible to gradually discard those families not transmitting the desired quality and keep only those that are most desirable. IMPROVEMENT OF VARIETIES 89 64. Results with mass and pedigree selection. — With all obvious characters, such as height or angle of ear, the same results to a certain degree ^will be obtained by either method ; but these results should be secured in less time by the pedigree method. This is rendered more comprehensive by conceiving a cornfield to be a mixture of types, and selection as a * ab The theory of isolating pure types by mass and pedigree selection is expounded at length by De Vries, in Plant Breeding. Open Court, Chicago. 90 CORN CROPS 65. Mass Selection. — The result of mass selection in corn is well illustrated by the history of any of the older varieties, as Learning, Reid, or Boone County White. After many years' selection, the breeder succeeded in producing a more or less uniform type. For example, the Leaming variety was originated by Mr. J. S. Leaming, of Hamilton, Ohio : ^ " After fifty-six years' selection, Mr. Leaming produced a corn having as variety characteristics a distinctly tapering ear, fairly large butts, rather pointed but well-covered tips, with kernels of a deep yellow color, with very irregular rows." Hartley produced a corn with twisted rows by select- ing such ears from the field. At the Nebraska Agricultural Experiment Station, a shallow-kerneled type of corn was fixed by continuous selection after five years.^ , 66. Pedigree selection. — A striking example has been reported from the Illinois station.' Two sets of Leaming TABLE XIII General Averages of Crops produced in Corn Breed- ing, FOR High Ears and for Low Bars Height oy Eab Height of Plant Year High-ear Plat Inches Low-ear Plat Inches High-ear Plat Inches Low-ear Plat Inches 1903 . . . 1904 . . . 1905 . . . 1906 . . . 1907 . . . 1908 . . . 56.4 50.3 63.3 56.6 ' 72.4 67.3 42.8 38.3 41.6 25.6 33.2 23.1 113.9 106.2 128.4 116.3 130.4 114.0 102.5 97.4 106.5 86.0 99.7 79.3 1 Mo. Agr. Exp. Sta., Bui. 87 : 113. 2 Nebr. Agr. Exp. Sta., Bui. US : 20. ' III. Agr. Exp. Sta., Bui. 132. 1909. IMPROVEMENT OF VARIETIES 91 ears, one borne high on the stalk and the other low, were selected in the fall of 1902. Continuous selection was practiced for six years, when a difference of about three feet in height was secured in the average crop, as shown by the table on previous page. Results were also obtained when selection was made to increase or decrease the angle of the ear, the erect-ear strain and declining-ear strain having average angles of 46° and 88.50° respectively, after six years. 67. Selection for composition. — ■ Composition can also be modified by continuous selection, as shown by the Illinois station.^ Ears of a single variety were selected for high-protein, low-protein, high-oil, and low-oil content, respectively. After ten years' selection, the high-protein TABLE XIV Ten Generations op Breeding Corn for Increase and Decrease or Protein and Oil Yeah High- Low- protein DlF- High- oil Low- oil DiF- Crop Crop Crop Crop Peh Cent Feb Cent Per Cent Per Cent 1896 . . . . 10.92 10.92 4.70 4.70 1897 11.10 10.55 0.55 4.73 4.06 0.67 1898 11.05 10.55 0.50 5.15 3.99 1.16 1899 11.46 9.86 1.60 5.64 3.82 1.82 1900 12.32 9.34 2.98 6.12 3.57 2.55 1901 14.12 10.04 4.08 6.09 3.43 2.66 1902 12.34 8.22 4.12 6.41 3.02 3.39 1903 13.04 8.62 4.42 6.50 2.97 3.53 1904 15.03 9.27 5.76 6.97 2.89 4.08 1905 14.72 8.57 6.15 7.29 2.58 4.71 1906 14.26 8.64 5.62 7.37 2.66 4.71 1 111. Agr. Exp. Sta., Bui. 128. 1908. U. S. Dept. Agr., Farmers' Bui. 366 : 314. 92 CORN CROPS selection contained almost twice as much protein (14.26 to 8.64) as the low, while the high-oil selection contained almost three times as much oil as the low (7.37 to 2.66). At the Nebraska station, pedigree selection for yield was practiced for five years in one case and two years in another, and an increased yield, amounting to nine bushels was secured in both cases. TABLE XV (Class I) Result of Five Years' Pedigree Selection for Yield. Bushels per Acre 1907 Bushels 1908 BnSHELS Average BtrSHELS Selected strains Check plats (original stock) . . 82.0 72.5 66.0 59.0 74.0 65.7 Difference 9.5 7.0 8.3 (Class II) Result of Two Years' Pedigree Selection for Yield 1908 Bttbhels Selected strains 68.0 Check plats (original stock) ... ; 59.0 Difference 9.0 References on type of ear and stalk : — Ohio Agr. Exp. Sta., Bui. 212. (1909.) Nebr. Agr. Exp. Sta., Bui. No. 91, p. 12 (1906) ; No. 112, p. 17 (1909). Nebr. Agr. Exp. Sta., Ann. Rpt. 1910, p. 154. Cornell Bui. 287. (1910.) 111. Bui. 132. (1909.) Hartley, C. P. Yearbook IT. S. Dept. Agr. 1909, pp. 309-320. IMPROVEMENT OF VARIETIES 93 References on methods of continuous pedigree selection : — 111. Exp. Sta., Buls. 74, 82, 100, 128. Conn! Exp. Sta., Buls. 152 and 168. Ohio Exp. Sta., Giro. 66. Nebr. Exp. Sta., Bui. 112. Directions to Cooperative Corn Breeders. Habtlet, C. P. (1910.) Bur. of Plant Industry, Wash., D.C. CHAPTER IX METHODS OF LAYING OUT A BREEDING- PLAT While the principle underlying systematic selection is simple, it has been more difficult to develop good methods for carrying out the selection work in order to avoid error. Breeding-plot methods have had a steady development, each step in advance being intended to overcome some source of error or to develop some new possibilities. In the reference on " Methods of pedigree selection," given on a previous page, several methods for conduct- ing a breeding-plat are given. The development of the breeding-plat plan may be smnmarized in the following brief way, beginning about 1895 : — 68. 1. Select a number of mother ears and plant in parallel rows, taking the yield of each row and saving seed ears from this row to continue in the same manner. (See 111. Agr. Exp. Sta., Bui. 55.) 2. The above plan was found to favor inbreeding and close breeding, with danger of decreasing yield. In order to avoid this it was recommended to detassel every odd row, sowing seed from only the detasseled rows. Thus, every odd row became a dam while the even rows would be the sires. By duplicating the plat and detasseling the even rows in the duplicate, seed could be saved from every mother ear. (111. Agr. Exp. Sta., Bulls. 82 and 100.) 94 METHODS OF LA TING OUT A BEEEDING-PLAT 95 3. About 1904 to 1906, Professor Williams, of Ohio, applied the " check row " system to the breeding-plat and developed the " ear remnant " plan. The " check row " was a composite planted for every sixth row. This was for the purpose of checking the uniformity of the land, as the breeder might unconsciously select for a breeding- plat a piece of land more fertile at one side than at the other. One difficulty found with the ear-to-row method in practice was that the best-yielding row might chance to be between two very poor yielders, so that seed ears saved from this row would be partly crossed with the poor- yielding rows on each side. In order to meet this diffi- culty, the plan was adopted of planting only a part of each ear, sufficient to determine the kind of progeny it would develop, and the remainder of the ear was kept. The next season, remnants of only the best ears would be planted in parallel rows and a part detasseled ; but with the poor-yielding rows eliminated, all the fertilization would come from desirable rows. (See Ohio Agr. Exp. Sta., Circ. 66 (1907) ; Amer. Breeder's Assoc, III: 110.) HOW TO CONDUCT A BEEEDING-PLAT 69. As there is considerable inquiry at present regarding methods of corn breeding, it seems best at this time to outline a plan which experience so far seems to recommend. Variety to use. — Select some variety that is well adapted to the region and is a good yielder. This is important, as one might spend years in working on a poor variety, and in the end have nothing better than the best variety already existing. It may be well to do some pre- liminary variety testing. 96 COBJV CROPS Selecting the ears. — If yield is to be the principal object of selection, it will not be necessary to hold closely to some one type of ear. In fact, since we do not know definitely what particular type of ear in a variety may do best in a new locality, it would seem wise to select several types, the main consideration being that the ears are sound and well matured. Number of ears to select as foundation stock. — Excep- tional ears are not common, there being probably not more than one in every fifty to one hundred ears. Therefore, if one starts with only a small number of ears, twenty- five to fifty, he may not find a single exceptional yielder in the lot. Not less than one hundred ears, and pref- erably two hundred should be tried out in the prelimi- nary trial. The test plat. — Great care should be exercised in pro- curing a uniform piece of land for the test plat, as every- thing depends on being able to compare in an accurate way the yields of the different ears. The land should not be exceptionally, rich, but only of the average fertility of the region. If the land can be plowed twice — say fall- plowed, and then backset in the spring — and disked sev- eral times, this will do much toward equalizing conditions. Size of plat. — Half an ear will plant a row 16 to 20 rods in length. However, there will be less error if the rows are duplicated, and it is best to plant two rows 8 rods long from each ear. One hundred ears will make two hundred plats 8 rods long. This will take a piece of land 32 by 11 rods or 16 by 22 rods ;' or two test plats, one-half this size on different parts of the farm may be used, dupli- cating the experiment in each. Check plats. — No matter -how carefully the land is selected, it may lack uniformity; for this reason, check METHODS OF LAYING OUT A BESEDINO-PLAT 97 plats should be planted with a uniform lot of corn. It has been found very satisfactory in practice to make every fifth plat a check. The simplest way is to make a check of every plat that is a multiple of 5, as 5, 10, 15, and so on. Planting the ears. — The land should first be laid off by a marker into checks 3 feet 8 inches apart. The planting must be done by hand. Carry the ear, and shell off the grains as needed. It is best to plant four grains in a hill; then, when the corn is 6 inches high, thin it down to two stalks. This will give a perfect stand. Every precaution should be used to secure uniform con- ditions in each plat ; otherwise the experiment would be a waste of time, as the results would not mean anything. Cultivation. — Ordinary cultivation should be followed, care being taken that none of the rows are unduly injured. Taking notes. — Some breeders prefer to keep extensive descriptive notes for their own information, but for practical results, very little note-taking is necessary other than accurately to secure comparable yields. If the breeder is selecting for some particular quality, such as earliness, height of ear, angle of ear, and the like, he must take notes on these points. Also, taking a set of notes on each individual row furnishes the very best train- ing possible in close observation ; and as a man cannot know too much about the corn plant in order to be a successful breeder, it will usually pay him well to keep as complete a record as possible. 70. Harvesting. — ■ When corn first ripens it contains 25 to 30 per cent of water, but it slowly dries out to about 15 per cent. In the breeding-plats some rows ripen and dry out sooner than others ; hence, the weights will not be comparable until all are equally dry. For this reason H 98 CORN CROPS it is best to leave the breeding-plats in the field for six to eight weeks after ripening, or until about December 1. Any very late-maturing or slow-maturing rows should be noted and discarded at harvest, as a type that will not mature well is undesirable. A very good method of harvesting the plats is to divide a wagon box into two to four compartments. Husk a plat into each compartment. At the end of the rows, have a platform scale with a box large enough to hold the corn from one plat. Scoop the corn into this box, and as each plat is weighed, dump the corn at the end of the row, leaving the plat stake with each pile. Leave the corn in these piles until all plats are husked, then mark the piles from high-yielding rows. A careful examination can now be made of these piles in order to note whether any seem immature, low in vitality, or other- wise undesirable. About one-fourth of the best plats should be noted, that is, 20 to 25 out of 100 piles. From these, seed for the general crop may be selected for the nest year. The breeder still has one-half or more of the original ears from which the crop has grown. It is from these that he will build up his improved strains of corn. 71. The second year's work. — The best twenty or twenty-five original ears having been located, the rem- nants of these are again planted in separate rows the second year. The reason for so large a number of the remi^ants being again planted is because the degree of error may be so large — ■ due to the fact that one season may favor a certain type — that we cannot determine exactly, the first year, just which are the best two or three for all seasons. When the second year's results are obtained, we may decide which to choose on the basis of two years' record. The METHODS OF LAYING OUT A BREEDING-PLAT 99 seed from the best two or three rows may now be used as foundation stock for a select strain of corn. When the original ears are large, there will be quite a remnant left even after testing two years. 72. Continuation of breeding, several plans. — After the second year, a choice of several plans may be followed : — 1. Progeny of the best rows may be planted in a mul- tiplj-ing field for seed. Seed of this kind has given an increase of 9 bushels per acre (p. 92, Class II). It prob- ably will not maintain its increased yield more than a few years without continued selection. 2. Ears may be selected from the best-yielding rows and the ear-row selection work continued. In this case it would be best to use some plan for preventing close breed- ing. Detassel every alternate ear-row plat having un- related rows on each side. Save seed ears only from the best detasseled plats. This may be continued indefinitely, but it is probable that new ear-row plats should be started every two or three years for the purpose of securing new ears to be used as sire rows in the breeding block, thus giving a new stimulus through crossing. No work has yet been reported to show just what results are to be expected. 3. The original ear remnants may be used in a breed- ing block. Williams advocates this, using the best one or two ears for sires and detasseling the rest. The ear- row test is to be continued each year, securing ears from various sources, as the breeding-plat, general crop, or registered ears from other breeders. Each year the best remnants will be saved to be crossed the following year and passed into the multiplying plat the following season. 4. As the best-yielding ears may be hybrids of the 100 COSN CROPS " elementary strains that nick well," plants from the best ear remnants could be used for inbreeding for the purpose of securing pure strains. There is more chance of secur- ing strains that will cross well from these ears than when plants are taken at random. After pure strains had been secured that would cross to advantage as determined by experiment, these strains would be grown from year to year in isolated fields and used each year to produce first-generation hybrid seed. SUMMARY 73. No fixed relation has been found between type and yield. The largest well-matured ears growing under normal conditions of soil and stand should be used for seed. Large ears with a medium depth of grain usually mature better than large ears with a very deep grain. Mass selection and pedigree selection will ultimately give similar results when visible characters are chosen, as height of ear or shape of ear ; but with invisible char- acters, as ability to yield, results are not so sure with mass as with pedigree selection, and at best they will come slowly. Pedigree selection involves the testing of each ear sepa- rately for yield, by planting a part. The remnants of best ears may be used directly as a foundation stock and the progeny may be continued in some system of ear-to- row selection. The very highest values will be secured by systematic crossing of the best strains. CHAPTER X RESULTS WITH HYBRIDIZATION Pebhaps no cultivated plant has yielded so many inter- esting results of both practical and purely scientific value, as a result of hybridization, as the corn plant. Corn freely hybridizes, thus offering many opportunities for the selec- tion of natural hybrids. The plant is so easily manipu- lated in artificial crossing, that almost any one may succeed ^with it who would fail with other crops. Not only have important results been secured bearing on the improve- ment of yield in quality of corn, but also interesting scien- tific data relating to the hereditary laws governing plants and animals, have also been secured with corn. DEGREES OF RELATIONSHIP 74. When pollen of a maize plant falls from its own tassel on its own silk, this is called " inbreeding." When pollen from one variety is used to fertilize another variety, it is called " broad breeding." There are several interme- diate grades of relationship, which may be summarized as follows : — 1. Inbreeding (pollen from own tassel). 2. Close breeding (pollen from sister plant, that is, plant from the sanie ear). 3. Narrow breeding (pollen from plants of the same variety). 101 Fig. 29. — Chart showing possible degrees of relationship between corn plants. (See text.) 102 RESULTS WITH HYBRIDIZATION 103 4. Broad breeding (pollen from plants of a different variety). 5. Broad breeding (pollen from plants of a different group, as between flint and sweet corn). XENIA 75. Cross a common dent corn on a sweet corn, using pollen from the former. When the ear is mature, instead ^^^B^^ '^^'j^^^. Th^hI ^(^^^ 1 ^^^^^^^^H 7: Afl| n^^^^l flffW "'^^H ■n ^^^H B^'^^^^^^I^K' J^F ^ ' ^KamJM Q ^Kf r^M^^H^^E^^ii^'^I^Hl ^31 ^Hw .mH^^^^^h #^^K' '^l|^H Bh BMBJH MH ^^^^^■iv^^r^3^ji3wK^^'^ISl^^^B^ H Fig. 30. — Method of covering tassel and ear for artificial pollination. of the kernels being wrinkled and translucent as in sweet corn, a part of them will be smooth, resembling a dent 104 CORN CSOPS corn. This is called xenia, or " the immediate effect of pollen on the endosperm." The effort of xenia, however, is limited to the kernel, there being no apparent effect on the cob or on the stalk. In ordinary hybridization, only the germ is a hybrid and the endosperm surrounding is not affected. Xenia is accounted for by "double fecundation." In ordinary fertilization, only one of the two generative nuclei which are formed in the poUen tube is supposed to pass into the embryo sac and unite with the egg cell. In double fecundation both nuclei enter the egg sac, one fusing with the nucleus of the egg cell, and the other with the polar nuclei to form the embryo sac nucleus, the division of which gives rise to the endosperm. The endosperm would then be a hybrid and partake of the dominant characters of the male parent. The fact that only a part of the kernels show xenia, means that double fertilization does not always take place. It is neces- sary that the germ cell be fertihzed, but it appears at present that fertilization of the endosperm nucleus is incidental rather than necessary. Mendel's laws 76. If crossed or hybrid kernels of dent and sweet com be planted, they will produce ears having both dent and sweet corn kernels, with a ratio of three dent corn grains to one sweet corn grain. This is explained by assuming that the germ cells (pollen grains or ovaries) are either pure sweet corn or pure dent corn. When a plant is grown from a hybrid seed, then, one- half the pollen grains will represent pure sweet corn, and one-half pure dent corn, and the same with the ovaries. While the plants may be hybrid, the sexual elements re- main pure. In the process of fertilization a union produc- ing a hybrid (sweet X dent or dent X sweet) will occur twice as often as a pure dent (dent X dent) or a pure sweet (sweet X sweet). RESULTS WITS HYBRIDIZATION 105 All the hybrid kernels resemble the dent corn kernels, so we apparently have three dent kernels to one sweet kernel on each self-fertiUzed hybrid ear. If the seed of one of these hybrid ears be sown, we apparently harvest three starchy ears to one sweet ear, as follows : — Gehm Cells Charactek of Pboqeny Starchy x starchy Starchy x sweet Sweet X starchy Sweet X sweet starchy Starchy Starchy Sweet DOMINANT AND RECESSIVE CHARACTERS 77. In the above example, every hybrid ear has a starch grain and cannot be distinguished, on inspection, from a pure starchy type. Starchiness in this case is dominant over the sweet corn grain ; or, in an ear that is a hybrid of dent corn and sweet corn, instead of the dent and sweet corn types blending, thus giving an intermediate, the dent completely dominates. In this case the sweet corn is recessive. By experiment this quality has been determined for many characters of maize, the following being typical examples : — Red colors of cobs, stem, or husks dominant over green. Starch endosperm dominant over sweet endosperm. Yellow endosperm dominant over white endosperm. Blue aleurone dominant over colorless aleurone. Red pericarp dominant over colorless pericarp. Podded kernels dominant over naked kernels. RESULTS WITH HYBRIDIZATION 107 HYBRIDIZATION, EFFECT ON GROWTH 78. Two very distinct results follow cross-fertilization in maize : first, certain hereditary characters from both parents are bound up in the embryo, to be carried over into the next generation ; second, a stimulus to vegetative growth is given, to be carried over into the hybrid genera- tion. The carrying over of hereditary characters has already been discussed under the topics " Xenia " and " Mendel's Law," and the principal discussion here will deal with the second effect of hybridization. SELF-FERTILIZATION 79. If a maize plant is self -fertilized (own pollen on own silk), and this process is repeated for two or three genera- tions, and selected seeds are used, there may gradually be produced a " pure type." That is, the wide range of variation is decreased each year, until the progeny of the individual, being self-fertilized, are all of one type. For example, ShuU self-fertilized corn plants of a white dent variety for five years and, as a result, secured strains that came true with 8, 10, or 12 rows, and so on up to 24-rowed ears. The pure strains differed also in other respects, but all the plants of a given pure strain were very similar. At the Nebraska Agricultural Experiment Station ten very distinct strains were isolated from Hogue's Yellow Dent, by inbreeding for three years. The inbred strains also become dwarfish in size, have a high percentage of barren plants, and sometimes become entirely sterile. The decrease in yield is illustrated by the following data from ShuU. Two strains, designated as A and B, which 108 CORN CROPS had been inbred for five years and appeared to he pure strains, were compared with the original com. The table also summarizes results with four strains of Leaming inbred by East, and a combination of several strains of Hogue's Dent inbred by Montgomery : — TABLE XVI EXPERIMENTEE Description of Seed Yield PEE ACEE or Geiginal Steain BnSHELB Yield peb Ache of Inbred Strain. (Number of Years Inbred at Head of Columii) 1st 2d 3d 4th 5th ShuUi . . . East 2. . . . Montgomery ^ . Pure strain A Pure strain B 79.4 79.4 88 40.7 50.1 59.9 49.0 9.9 51.8 14.2 12.1 ' Ann. Rpt. Amer. Breeders Assoc, Vol. VI: 63-72. 1909. 2 Conn. Agr. Exp. Sta., Bui. 168. 1911. s Nebr. Agr. Exp. Sta. Ann. Rpt. 1912 : 183. It is evident from these data that the immediate effect of seK-fertilizatibn is to reduce the yield, the greatest reduction taking place the first year. The amount of decrease seems to differ with varieties, or even with strains of the same variety. In general, inbreeding will decrease yield to about one-half the first year. Continuing the inbreeding will in some cases reduce the yield to one-fourth the original yield, while in other cases, inbred strains become entirely sterile. Present experiments indicate that the yield is reduced until the strain becomes a " pure strain," after which inbreeding has no further effect in decreasing yield. Very often abnormal types appear in inbred strains. RESULTS WITH HYBRIDIZATION 109 Fig. 32. — The effect of three degrees of relationship in crossing is here illustrated. Nos. 3 and 4 are pure strains inbred for three years. No. 2 from a close fertilized seed-stock, the plants each year fertilized from sister plants from the same ear. No. 1 is from a seed-stock, cross fer- tilized for three years. PURE STRAINS, OR BIOTYPES 80. Doctor ShuU first presented the idea that a corn- field is to be considered more or less a mixture of pure types (biotypes) and that most of the plants in a field are more or less complex hybrids. By inbreeding, some of the original pure types might be isolated. In other words, a cornfield is a complex mixture of types, and inbreeding gives much the same result as does a chemical analysis with a complex compound — resolves it into its original elements. mm \ J^ -1 f"""^^ ^ V T^-^-'l ■ y Fig. 33. — Pure types such as may be originated from a single variety or ear of corn by inbreeding. They are reduced in size, but each type comes true. 110 BE8ULTS WITH HYBRIDIZATION 111 CROSSING BIOTYPES 81. However, these " elemental strains " are low in yield, but are stimulated to yield by hybridizing. The effect of hybridizing as a stimulus is shown in the following table : — TABLE XVII Experimenter Description of Seed Yield per Acre of Pure Strains Bushels First-tear Yield per Acre of Cross of Pure Strains Bushels Second-tear Yield per Acre OF Progeny prom Hybrid Seed Bushels ShuU . . East . . {Pure type A [Pure type B Learning No. 12 Learning I No. 9 14.21 12.l| 35.4 . 23.3 79.8 110.2 69.5 98.4 The corn is at once restored to full vigor by hybridizing. The yield appears to decrease somewhat the second year, probably because a certain percentage of the plants have returned to a pure-type (homozygous) state. Under natural conditions there is a certain percentage of both inbreeding and close breeding. This has led to the suggestion that means should be used to insure that all seed used is first-generation hybrid. This can be accomplished by alternating rows of pure strains and detasseling every alternate row, saving seed from the detasseled rows. CBOSSING VARIETIES 82. Several investigations have shown an increase from the use of first-generation hybrid seed, when two varieties have been crossed. The following table, summarized from 112 COMN CROPS Morrow and Gardner's experiments in 1892 at the Illi- nois Agricultural Experiment Station, illustrates : ^ — TABLE XVIII Vametit Bushels of AlR-DBY COBN Burr's White . . . Cranberry .... Average . . . Cross .... Burr's White . . . Helm's Improved Average . . . Cross .... Leaming Golden Beauty . . Average . Cross .... Champion White Pearl Leaming Average ... Cross .... Burr's White . . Edmonds .... Average . . . , Cross .... 64.2 61.6 62.9 67.1 64.2 79.2 71.7 73.1 73.6 65.1 69.3 86.2 60.6 73.6 67.1 76.2 64.2 58.4 61.3 78.5 The average yield of hybrids in the five tests was 9.7 bushels above the average of the parents and 4.5 bushels above the average of the highest parents. It is also shown, by this and other data, that certain crosses give 1 lU. Agr. Exp. Sta., Bui. 26. 1902. RESULTS WITS HTBEIDIZATION 113 greater increases than do others. Hartley has found that, while certain crosses give an increase, others give a decrease, and in some cases the cross is almost sterile. Probably those varieties that have been longest selected m mm . 1 l^llP'm 1. W T-y^'-M^ ?>.%.t!!i-^>%^^ r*-''-:^ ■'fi .;^ M-^y,: "^^' ' ■^^ Fig. 34.- - A breeding plat where many tassels and ears are covered with paper bags, for artificial pollination. as to type, and therefore are the nearest to a pure (homo- zygous) state, will respond most readily to crossing. 83. ShuU has found that when a variety has been resolved, by inbreeding, into pure strains, certain of these pure strains when crossed give yields superior to the yield of the original corn, while other combinations give poor yields. He suggests that the maximum yields will be secured by first reducing a variety to its elemental strains, and then producing hybrid seed each year from only 114 CORN CB0P8 those strains that give maximum results. This would necessitate maintaining the pure strains each in a separate field from year to year, and having another seed field where Fia. 35. — Pure tj^pes as developed by inbreeding. No. 11 produces many tillers, and was reddish in color. No. 12 was free from tillers. they would be planted in alternate rows. One strain would be detasseled in this seed patch, thus giving each year a stock of hybrid seed. RESULTS WITH HYBRIDIZATION 115 ISOLATING HIGH-YIELDING BIOTYPES 84. Evidence at present indicates that high-yielding ears, found by the ear-row method of testing, are in many cases natural hybrids of high-yielding biotypes. Thus by sectiring high-yielding ear remnants as foundation stock, they might be inbred until pure types were ob- tained. There is greater probability of securing biotypes that would combine to advantage from this stock than if a chance stock were used as a beginning. SUMMARY 85. Fertilization is the result of the union of the con- tents of a pollen grain with the egg cell of an ovary. Xenia is the immediate effect of pollen in changing the character of the maize grain. Mendel's law refers to the phenomenon of transmitting characters in toto, without blending, as in the case of dent and sweet corn when crossed. Hybridization usually gives a decided stimulus to growth, while self-fertilization has the opposite effect. Continuous self-fertilization may reduce yield to one-fourth or less of the original yield, but the yield is fully restored in the first generation hybrids. A field of corn appears to be a miscellaneous mixture of biotypes, naturally not very productive, but stimulated to the highest degree of pro- ductivity by hybridizing. Certain biotypes hybridize to better advantage than do others. ^ References on xenia : — Webber, H. J. (1900.) Xenia. U. S. Dept. Agr., Div. Veg. Physiol, and Path., Bui. 22. GuiGNAED, L. (1901.) La Double Fecundation dans le Mais. Journ. Bot. [Paris], IB : 1-14. No. 2. 116 CORN CBOPS References on inheritance in maize : — CoRKENS, C. (1901.) Bastarde zwischen Maisrassen mit Beson- derer Berucksiehtigung der Xenien. Bibliotheca Bot., 53 : 1-161. Lock, R. H. (1906.) Studies in Plant Breeding in the Tropics, 111. Ann; Roy. Bot. Gard. Peradeniya, 3 : 95-184. East, E. M. A Note Concerning Inheritance in Sweet Corn. Science, N. S. 25 ; 465-467. 1911. Inheritance in Maize. Conn. Agr. Exp. Sta., Bui. 167. Emmbhson, R. a. (1911.) Genetic Correlations and Spurious Allelomorphism in Maize. 24th Ann. Rpt. Nebr. Agr. Exp. Sta. References on crossing varieties : — Collins, G. W. (1909.) The Importance of Broad Breeding in Corn. U. S. Dept. Agr., Bur. Plant Indus., Bui. 141. (1910.) The Value of First-Generation Hybrids in Corn. U. S. Dept. Agr., Bur. Plant Indus., Bui. 191. Increased Yields of Corn from Hybrid Seed. U. S. Dept. Agr. Yearbook 1910 : 319-328. MoBBOw, G. E., and Gardneb, F. D. (1892.) Field Experi- ments -with Corn. 111. Agr. Exp. Sta., Bui. SS : 173-203. Kellebman, W. a., and Swingle, W. T. Ann. Rpt. Kans. Agr. Exp. Sta., No. i .• .316-337, 1889; No. S: 288-355, 1890 ; and Kans. Agr. Exp. Sta., Bui. 27 .■ 139-158. (1891.) East, E. M. Conn. Agr. Exp. Sta., Bui. 167. 1911. Haetley, C. p., and associates. Cross-breeding Corn. U. S. Dept. Agr., Bur. Plant Indus., Bui. 218. CHAPTER XI ACCLIMATION AND YIELD A BOTANICAL survcy of the United States shows large, well-defined regions, each with a characteristic native flora. 86. Considering the great length of time that native vegetation has had in which to adjust itself, these various Fig. 36. — Prairie vegetation in the " short grass " region. The natural vegetation indicates a very great difference in natural climate. regions must indicate different environmental conditions, or else we should have a homogenous native vegetation throughout the country. Those regions covered with a forest vegetation must differ in environment (soil or cli- mate) from a prairie region. There are various kinds of forest regions, as evergreen and deciduous; while in the 117 118 CORN CROPS prairies we have, along the Missouri River, a tall vegeta- tion of grass and other plants, waist-high to a man, in Fig. 37. — Prairie vegetation in humid region. Compare with Fig. 36. There must be quite a marked difference in the types of corn adapted to these two regions. marked contrast to the " short grass " country three hun- dred miles westward. Even within a State distinct floral zones can often be identified, as in Nebraska, for example, where six zones are recognized, each with a characteristic vegetation. EFFECT OF ENVIRONMENT ON THE CORN PLANT 87. It has long been observed that each region would have a distinct type of corn plant. In northern regions the plant is leafy with the ear borne very low; in dry regions the plant is stocky, with a high proportion of ear and often with scant leaf ; while in southern regions the ACCLIMATION AND YIELD 119 plants are tall and have a low proportion of ear to stalk. EFFECT OF PREVIOUS ENVIRONMENT ON YIELD 88. The marked effect of a change in environment on yield of grain has often been noted, the change usually- decreasing the yield at first. At the Arkansas station/ 233 samples of corn were collected from various States and grown in comparison for two years. In 155 trials with seven varieties, the highest yield was secured with seed grown between the thirty-fifth and thirty-eighth parallels of latitude, rather than either north or south of this region, this being the latitude of the Arkansas station. TABLE XIX Table showing the Yield op Corn pbom Seed op Dipper- ENT Sources at the Arkansas Agricultural Experi- ment Station Names of Varieties Num- ber OF Tests Seed grown North of 38th Parallel of Latitude Seed grown BETWEEN 35th AND 38th Parallels of Latitude Seed grown South of SSph Parallel of Latitude Average for 2 Years Average for 2 Years Average for 2 Years Learning . . . Golden Beauty . Hickory King . Golden Dent Champion White Pearl . . . Early Mastodon White Dent . . 21 20 23 26 11 16 38 20.98 32.81 24.855 21.52 22.62 33.54 24.175 23.20 45.775 31.81 25.00 32.00 33.75 34.695 17.20 50.475 29.10 25.30 30.10 33.45 34.775 Average Total 155 25.785 32.47 31.485 1 Newman, C. L. (1899.) Ark. Agr. Exp. Sta., Bui. 59. 120 COEN CROPS At the Nebraska Agricultural Experiment Station six leading varieties of corn were compared for two and three years, the seed in one case being native-grown and in the other from Iowa or Illinois. Results were as follows : — ■ TABLE XX Table showing Yield op Corn phom Acclimated Seed and Seed prom Other Regions, at the Nebraska Agricultu- ral Experiment Station Name and Places of Origin 1903 1901 1905 Average DlFFEH- ENCE 0-1 • f Nebraska . . Silvermme 1 jjy^^jg . . . T . [ Nebraska . . . Learning jjjjj^^j^ Snowflake f Nebraska . . White I Iowa .... Boone County | Nebraska . White 1 Illinois . . Early Yellow f Nebraska Rose 1 Iowa . . . Reid's Yellow f Nebraska . Dent Illinois . . 73.7 68.7 68.1 62.1 70.0 65.1 95.2 76.6 84.8 72.8 76.2 68.9 67.9 76.9 83.8 82.8 76.1 63.4 69.8 72.3 74.5 67.1 75.1 63.5 64.2 60.8 73.0 64.2 82.5 74.4 77.7 69.5 76.2 68.9 70.3 67.5 73.7 71.8 8.8 8.1 8.2 7.3 2.8 1.9 Average 6.2 In every case the native seed gave best results. In another experiment conducted with farmers in western Nebraska, it was found that native-grown seed gave better results than seed grown in eastern Nebraska. * Rainfall in the western part of the State is very low, averaging about 18 inches annually, while the rainfall is about 30 inches in eastern Nebraska. To succeed in the West corn must be adapted to drought resistance. 1 Nebr. Agr. Exp. Sta., Bui. 126. 1912. ACCLIMATION AND YIELD 121 TABLE XXI Table showing Comparative Yield op Native- and Im- pobted-seed corn in western nebraska in bushels PER Acre Yeak Vahieties not Native (mostly FROM EaSTEBN Nebraska) Native Varieties Difference 1908 .... 1909 .... 24.1 20.9 30.5 25.4 6.4 4.5 Average . . . 22.5 27.9 5.4 ADAPTATION OF THE SOIL 89. The climatic and soil requirements of corn have been stated in Section II. The climate cannot be controlled or modified in a marked degree, hence corn production is limited by climate to those regions where the natural rainfall, temperature, and like conditions are favorable to a profitable production. The soil, however, is subject to treatment, and almost every soil can be brought to a high degree of productive- ness by proper management. The subject of soil manage- ment is so fully treated in special texts on this topic, that it is not necessary to take up the matter in detail here. From a study of corn soils as classified according to productiveness, it is apparent that a large proportion of the soil likely to be cultivated in corn may be grouped in two classes : first, soils that were once productive but are now more or less deplete by 50 to 200 years cropping ; and second, soils that never were productive. In both cases the important factors to be modified can be grouped under three general heads, as follows : (1) organic matter, (2) mineral matter, (3) water. CHAPTER XII CROPPING SYSTEM IN RELATION TO MAIN- TAINING THE YIELD OF CORN The discussion so far, on the adaptation of soil for com growing, brings out the fact that the constant growing of corn involves the development of a cropping system by which, with the least cost, the organic matter can be maintained and the most profitable use made of any fertilizing material that it may be necessary to add. 90. Cropping systems in the United States undergo evo- lution from the time when new land is opened up to the time when it reaches a permanent agricultural basis. When new land is first brought under cultivation, grain farming is the general custom. Often a single crop is cultivated, as wheat in the Northwest. In a few years the single crop becomes unprofitable, due to the coming of insect pests or plant diseases, or to the decreasing avail- ability of some mineral element in the soil. Then cul- tivated crops are introduced to alternate with the small grain. In many regions of the Corn Belt, corn was continu- ously raised until it became necessary to introduce small grain culture. After a time, however, the continuous rotation of grain crops alone no longer gave paying crops. In general, this appears to be due to : — 1. Exhaustion of actual organic matter resulting in (a) Decrease in availability of some necessary element as phosphorus, or (b) Poor physical condition of the soil. 122 CROPPING SYSTEM 123 2. Exhaustion of some necessary element, usually lime, nitrogen, phosphorus, or potassium. BESTORING PRODUCTION 91. When low production is due to the exhaustion of organic matter, then any cheap system of restoring that matter, as plowing under a green manure crop, will usually restore production in a measure. One effect of this de- caying organic matter is the reaction on the minerals of the soil, thus increasing solubility, and restoring the physical condition. The physical effect is to make the soil more loamy in character by increasing granulation of clay, on the one hand, and on the other hand, in the case of sandy soils, binding the particles together. In this case no new supply of plant food is added to the soil, as the organic matter is grown on the land and only adds to the soil the carbon compoimds taken from the air. Adding organic matter from an outside source, in addition to the above, also adds its own supply of elements. When a certain element has been exhausted from the soil, that element may be added. Nitrogen may be added in three ways : (1) by growing leguminous crops ; (2) by adding organic matter from an outside source ; (3) by adding nitrogen salts. Phosphorus, potassium, and lime can be restored in two ways : (1) by adding organic matter from an outside source ; (2) by adding salts of phosphorus, potassium, or lime. Aside from a proper system of drainage where needed, the whole problem of devising a cropping system, includ- ing the application of fertilizers for maintenance or in- crease of production, is involved in the above statements. 124 COUN CROPS Cropping systems may then be classed as : — (1) Those that decrease productivity. (2) Those that maintain productivity. (3) Those that increase productivity (or in most cases merely restore it) . Experiments demonstrating the above cases have been made in a number of States where corn was used as one of the crops in the system. MAINTAINING PRODUCTION 92. Results are reported from the Illinois station, "^ where corn has been grown in three systems of cropping, for 13 years in one case and for 29 years in the other. TABLE XXII Illinois Corn Yields where Three Systems of Cropping ABB Compared. Average Yield fob Last Three Years Ckop Yeabs Chop System 13-YBAE Experiments Bushels 29-TEAB expehiments Bushels 1905-6-7 . . 1903-6-7 . . 1901^t-7 . . Corn every year Corn and oats Corn, oats, clover 35 62 66 27 46 58 The land on which these experiments were conducted originally produced more than 70 bushels per acre. There has been some decrease in yield in all cases, but less de- crease where rotation was practiced. Yield cannot be maintained by rotation alone where the crops are removed. In a second series of plots a corn-oats-clover rotation was practiced, where all was returned to the land except the grain and clover seed harvested. In one case, the straw, iIU. Agr. Exp. Sta., Bui. IBS ; 324. 1908. CROPPING SYSTSM 125 cornstalks, and clover were all plowed under, and this system was designated as " grain farming " since no live stock to produce manure was needed. ^ ^ 1 1 ■ImB fiaEHPHHly »JBHiHHbKj ^^m i 1 S^ia-.^ v«?f 1^^ ^P P^ M ■ "'t;^ 9 Fig. 38. — Good land, continuously cropped with grain, until it is in an unproductive state. In a second series, designated "live-stock farming," the crops have been removed but equivalent manure returned. Grain Live-stock Crop Yeabs Special Theatment Legumes ^ Manube 2 Bushels Bushels 1905-6-7 . . None 69 81 1905-6-7 Lime 72 85 1905-6-7 . . Lime, phosphorus 90 93 1905-6-7 . . Lime, phosphorus, potassium 94 96 ' Legume catch-crops and crop residues. ' Manure applied in proportion to previous crop yields. Growing legumes and returning all residues has main- tained yield, and when in the form of manure has increased 126 COBN CROPS yield. When additional minerals have been added, the crop production has been actually increased about 20 per cent. At the Indiana station ' five cropping systems have been compared for 20 years, with and without commercial fertihzers. Without giving details, the following table shows clearly enough the comparative effect of different cropping systems on the maintenance of production. TABLE XXIII Indiana Expebiments, comparing Coen Yields at Begin- ning AND End of Twenty-year Period in Different Rotations Treatment Cropping Systems and Yields in Bushels per Acre Continuous Corn II Corn and Wheat III Corn, Oats, Wheat- Clover IV Corn, Oats, Wheat, Clover- Grass V Corn-roots, Oate, Wheat, Clover- Grass Unfertilized . Fertilized Yields in 1889 "when the Experiments were Begttn 61.1 62.1 50.0 49.3 54.6 54.8 54.2 56.4 58.4 58.1 Yields in 1909 after 20 Yeahb' Chopping Unfertilized . Fertilized 26.0 39.9 25.4 47.3 47.8 59.1 35.5 65.5 61.1 73.1 DlFFERE> ce between 1889 and 1909 yields Effects of Rotations , SHOWING Unfertilized . Fertilized -35.1 -22.2 -24.6 -2.0 -6.8 + 4.3 - 18.7 + 9.1 + 2.7 + 15.0 1 Ind. Agr. Exp. Sta., Circ. 25. 1911. CROPPING SYSTEM 127 The Indiana results confirm the Illinois experiments, showing : (a) a rapid decrease for continuous grain culture ; (6) a maintenance of yield for longer period when a rotation including legumes and grass is included ; (c) an Fig. 39. — Compare with Fig. 38. The same kind of land near by, but properly managed to maintain productivity. (Minn. Exp. Sta.) actual increase in productivity when fertilizer is added. However, fertilizer did not maintain yield in a grain rotation. ROTATIONS FOR CORN GROWING 93. The above tables suggest the type of rotations and fertilizer treatment for the Corn Belt. Other stations have suggested rotations including corn, as follows : i — " A rotation for dairy farms recommended by the New Jersey station consists of (1) field corn, seed to crimson clover in July or August ; (2) crimson clover followed by 1 U. S. Dept. Agr., Farmers' Bui. 144: 11. 128 CORN CROPS fodder corn, land seeded to winter rye ; (3) rye fodder, followed by oats and peas, seeded to red clover and timothy ; (4) hay. [Crimson clover is not hardy north of New Jersey. — Authob.] " A three-year rotation for the South, recommended by the Louisiana station, is (1) corn ; (2) oats, followed by cowpeas; and (3) cotton. " At the Delaware station a good rotation for a poor soil in bad condition was (1) sweet corn, crimson clover ; (2) cowpeas, winter oats ; and (3) red clover. A fertiUzer was applied. The results reported indicate that it is better to have crops growing continuously up in the land, than to have it Ijdng idle dicing a part of the growing season." Each farmer must work out the rotation system best adapted to his own situation, but the general lines to fol- low are indicated in the foregoing discussion. CHAPTER XIII ORGANIC MATTER FOR CORN LAND Obganic matter has several important functions in the soil : (1) As a direct source of food supply. Decaying vegetable and animal matter contains all the essential food elements of plants. (2) As a means of freeing unavailable plant food elements in the soil. The organic acids given off by decaying organic matter act directly on the elements of the soil, in bringing them into solution. (3) The phys- ical condition of the soil is affected in a remarkable degree by the presence of even a small percentage of organic matter. Note the effect on a clay soil when a few loads of manure are applied to an acre of land. The organic matter improves the granulation and increases the water- holding capacity to some extent. Aeration is also im- proved. (4) A very important effect is to improve the soil as a medium for the growth of soil bacteria and fungi, which in tm'n become a source of organic matter to the soil. (5) Nitrogen-fixing bacteria are favored by abundant organic matter, if sufficient lime be present. Considering the fact that corn, in common with all cereals, must be grown without the extensive use of com- mercial forms of fertilizer, maintaining the supply of organic matter in the soil becomes the most important single consid- eration in extensive corn-growing regions. 94. Good corn soils are rich in organic matter. Two of the best corn soils in the Central States are Miami black K 129 130 COBN CROPS clay loam and Wabash silt loam, the organic matter of which, according to Lyon and Fippin,i is as follows : — Soil 0-7 Inches Per Cent Ohganic Matter Subsoil 7-40 Inches Peb Cent Organic Matter Miami black clay loam Av. 12 samples . Wabash silt loam Av. 11 samples . 2.50 1.30 Of all the cereals corn 'is the best crop to grow first, after a heavy application of manure or the plowing under of organic matter, as a clover sod or green manure crop. It is well adapted to utilize the rather large store of nitrogen likely to become available at such time. Be- cause corn does well following the plowing under of coarse organic matter, it is sometimes called a " coarse feeder " ; while wheat, requiring a more advanced stage of decom- position, is termed a " delicate feeder." FARMYARD MANURE FOR CORN 95. It has been demonstrated that lime, under certain conditions, applied to the land gave profitable increases ; in certain other cases commercial fertilizers have been profitable ; but farmyard manure, wherever used, has usually given profitable returns. It appears at present, however, that for a large share of the corn-growing area farmers are not justified in keeping sufficient live stock in their farming systems to depend on manure as the principal means of maintaining production. It must be ' Lton and Fippin. Soils, p. 125. ORGANIC MATTER FOR CORN LAND 131 m 1^ >-) H C3 2 m <* W |o oS 13 H ^>H O W H 01 m rn ^ 1% H , < g > OQ P ll M PQ PJ !« J O S E; S ^ g s « o O o g U h 03 ^3 P ^O xn M g ^ o o (M CO o < s^§ i-H lO l> ■* •1^ c4 N IN w s ;2 s© m m s© si g !5 1 r& IN IN g2 K m 1— ( e© m m -,H J *S '^ 00 lO CD o ^1 ii 00 CO CO d CO IN oo ■ag (N T— 1 !5« 5 e© ^ m ^ CD ■* 03 00 O ftg "* N 00 cq S 1-< T-H OJ ■^ IC -t^ ■* i-H +^ ■* I-H ll (2^ 1— 1 OO^glOgolO lO O O P3 5S O CO ■* IN °m ■&■)= 03 to I> '^ II ^ CO 00 s o; O^ rH ■* 00 Tt< ^■^ (N d CO lO 4) ■* CO CO CO E>:i R ^ i >> 4J g 1-^ 1^ 1 < O 4i o -i 1 oo • • 'o ' t> 0 ■ ^ . a K '3 S g a g a M g cS S • (D - ■ S .. =8 1 ili < 132 COBN CROPS supplemented by plowing under organic matter, especially green crops, containing enough legume crops to maintain the nitrogen supply. Perhaps the best comparative idea of the value of farm- yard manure and fertilizers can be obtained by examining certain data secured at the Pennsylvania station in a twenty-five-year test, two experiments at the Ohio station — one for sixteen years and the other for thirteen years — a nine-year test at the Indiana station, a thirteen-year record at the Illinois station, and a single corn crop after timothy at the Cornell station. The foregoing table is a summary of the data secured at . the Pennsylvania and Ohio stations. These are the best continuous records that we have in the older portion of the United States, where the use of manure and fertilizers is now becoming a matter of importance. The summary shows that land yielding, under a good rotation, an average of 35.4 bushels of corn per acre has been maintained at an average of 48.4 bushels for the corn crop by an average expenditure of $15.20 for commercial fertilizers (where a complete fertilizer was used) for each course of the rotation (average of four years). These complete fertilizers were fairly well mixed to meet the needs of the soils in each case. An average application of 11 tons of manure every four years has maintained the yield of corn at 51.82 bushels. The second part of the table shows the average financial returns for all crops grown during the course of rotation. Eleven tons of manure shows a better average return than $15.20 worth of commercial fertilizer, and an average return of $2.46 per ton for the manure. The Illinois station received a return of $1.60 per ton and the Indiana station $1.50 per ton for manure. Both the latter stations ORGANIC MATTER FOR CORN LAND 133 are on newer land, where as large increases are not yet to be expected as on old cultivated land. Again, the Ohio station ' has shown that the value of manure may be increased by adding and composting a small amount of mineral fertilizer with it. The following table summarizes the data, showing a marked increase in the value of the manure where treated with mineral fertilizer. TABLE XXV Value op Barnyard Manure treated with 40 Pounds per Ton op Different Minerals. Applied to Crops in A Three-tear Rotation op Corn, Wheat, and Hay at the Rate op 8 Tons per Acre. Average for Fourteen Years Plats No. Amendmemt Used Cost of 40 Pounds Cents Total Value OF Increase in One Rotation Net Value of Increase per Ton op Manure 2-3 . 5-6 .. . 8-9 . . . 12-13 . . 15-16 . . Floats Acid phos- phate Kainit Gypsum Untreated 18 30 34 12 «33.51 38.08 29.28 27.41 23.44 $4.01 4.46 3.32 3.30 2.93 In this case, the mineral was mixed with the manure as it was removed from the barns. A part was applied directly to the land in each case, and a part allowed to decay in the yards for about three months. The former method seemed to be the better. SUMMARY 96. In the foregoing discussion on the theory of applying fertilizers and manures for raising cereals, it appears that the permanent maintenance of the soil in a productive 1 OUo Agr. Exp. Sta., Circ, 1^0 : 112. 1912. 134 CORN CROPS state is the most fundamental problem in production. For cereal culture, the soil, must be maintained at the lowest possible cost. The four principal elements to be given attention in most soils are (1) nitrogen, (2) phos- phorus, (3) potash, (4) lime. In addition, active organic matter must be present. These conditions are met in the most practical way by : (1) A rotation in which legumes furnish a large share of the nitrogen used by other crops in the rotation. (2) Where manure is not available, practically all organic matter grown on the land, with the exception of threshed grain, should be plowed under. (3) In order to maintain the full supply of organic matter and nitrogen, it may be necessary to plow under the entire legume crop without harvesting. (4) Where live stock is kept, all manure made by feeding produce should be returned to the land in relatively light dressings. (5) The constant removal of grain will gradually reduce the phosphorus and potassium. This must be returned as commerical fertilizer. A part at least can be mixed with the manure and applied in this way. (6) Where fertilizer mixtures are applied to land, careful regard should be given to the needs of the land, and the fertilizer should be mixed to meet the particular needs in each case. (7) Where lime is required, it should be applied once every four to six years, the amount being determined by the needs of the land. CHAPTER XIV MINERAL MATTER FOR CORN LAND As pointed out heretofore (p. 42), about 1 per cent of the green weight or 5 per cent of the dry weight of corn is ash or mineral matter, taken directly from the soil. For the production of 50 bushels of corn the mineral ash found in composition would be as follows : — TABLE XXVI Mineral and Nitrogen Requirements op a 50-bushel Corn Crop' NrrEO- GEN Phos- phorus Potas- sium Mag- nesium Cal- cium Sul- fur Total Min- eral Total Ash Ears (3500 lb.) . . Stalks (3000 lb.) . . 50.0 24.0 8.50 3.00 9.50 26.00 3.85 4.80 .7 10.4 .14 3.00 3.14 24.29 64.40 43.4 69.5 Total . 74.0 11.50 35.50 8.65 11.1 88.69 112.9 97. Soils in regard to mineral supplies may be classed as : 1. Soils in which sufficient mineral matter in available form is present. 2. Soils in which sufficient minerals are present, but one or more of those minerals are unavailable or available in very limited amounts. 3. Soils in which one or more minerals are so deficient that even with good soil management a sufficient amount cannot be made available for a crop, the total supply being sufficient for only a few crops. 1 Hopkins, C. G. Soil Fertility, pp. 154 and 603. 135 136 COBN CROPS The first class included most of the present Corn Belt States when the land was first broken up. Large crops were grown without soil amendments, but to-day the yield is limited on most of these soils by the lack in available form of one or more mineral elements. In the second class, chemical analysis may show the presence of enough minerals and nitrogen for fifty to one hundred crops, and yet the crop be limited, as the minerals may become available only very slowly. This class includes a large share of the above-mentioned soils that have been farmed fifty to one hundred years or more. Decreased availability of minerals may be due to several causes, as deficiency in bases such as lime or magnesium, or more often insufficient organic matter in a state of active decomposition. The addition of lime or organic matter, or both, is the evident remedy in such cases. In other cases there is no practical way of making avail- able sufficient mineral elements for maximum crops, and mineral fertilizers must be added. In many soils there are other inhibiting factors to plant growth, even when mineral elements are abundant. This is especially true on poorly drained soils where toxic organic compounds are developed. In class 3 are included many of the sandy soils and soils subject to leaching, erosion, or derived from rocks that originally lack some mineral in composition. It is doubt- ful whether corn culture can ever be profitably developed on land of this class. An example is the sandy soil of Long Island, where most of the mineral must be supplied. Often a ton or more per acre of high-grade fertihzer is used. On such land only crops returning a large gross income per acre, as potatoes, cabbage, or truck, can be grown with profit. MINERAL MATTEB FOR CORN LAND 137 98. Hopkins ' believes it fair to " assume for a rough estimation that the equivalent of 2 per cent of the nitrogen, 1 per cent of the phosphorus, and J of 1 per cent of the total potassium contained in the surface soil can be made avail- able during one season by practical methods of farming." The above statement is borne out by results in many of the prairie soils of Illinois. The amount of nitrogen, phosphorus, and potassium in the surface, and the amount available annually on the above basis, is shown by Hopkins to be as follows : — TABLE XXVII Fertility in Illinois Soils and Amount Annually Avail- able IN Pounds per Acre (roughly estimated) A%'ERAGE PEH AcRE IN Surface Soils Anntiallt Available' (0-6| IN.) Soil Type No. Total Nitrogen Total Phos- phorus Total Potas- sium Nitro- gen Phos- phorus Potas- sium 330 Gray silt loam 2,880 840 24,940 58 8 62 426 Brown sUt loam . . 4,370 1,170 32,240 87 12 81 520 Black clay loam . . 6,760 1,690 29,770 135 17 74 • 635 Yellow silt loam . . 2,390 850 37,180 48 9 93 1401 Deep peat . 34,880 1,960 2,930 9 20 7 Amou nt required for 50-busl lel cor n crop 74 11.5 35.5 From the above tj^jical examples, it appears that many of these soils do not meet the requirements of a 50-bushel corn crop in all the three elements considered. 1 Hopkins, C. 2 Ibid., p. 82. G., I.e., p. 107. 'Ibid., p. 110. 138 COItN CB0P8 The problem of production on soils of this class is to increase availability through use of manures and organic matter, but in many cases the addition of some mineral supplement is now necessary. FERTILIZERS FOR CORN 99. Theory of fertilizer dosage. — If a perfectly sterile sand were used as a medium for growing crops, and it were desired to add fertilizing material, the logical method would be to ascertain the relative amount of mineral constituents in the plant under culture and add the minerals in the same relative proportion. For example, the three principal mineral constituents in the corn crop is shown in Table XXVI to equal, in a 50-bushel corn crop, 74.0 pounds of nitrogen, 11.5 pounds of phosphorus (or 26.3 phosphoric acid), and 35.5 pounds of potassium (or 42.6 potash) ; or the ratio would be about 6 : 2 : 3 for nitrogen, phos- phoric acid, and potash. If the amount of fertilizer applied were to equal the expected crop, then for a 50-bushel corn crop we should apply about the following formula : 74 lb. nitrogen = 400 lb. sodium nitrate 11.5 lb. phosphorus = 190 lb. acid phosphate 35.5 lb. potassium = 85 lb. muriate of potash Fertilizer for corn would not, however, be apphed to a sterile soil, but to a soil usually containing enough miner- als and nitrogen in an unavailable state for fifty to one thousand crops. Organic matter and lime, and thorough tillage, assist in making minerals available ; but after all reasonably good treatment has been given, some one or more elements may be found available only in such small amount that the crop is limited. MINERAL MATTER FOR CORN LAND 139 The fertilizer applied should be planned to supply the needed element or elements, rather than all elements. Also, a certain element may be deficient a part of the season but more plentiful at some other period. This is true of nitrogen, which is often deficient in early spring, especially on heavy clay soils, but may be more abundant by mid- summer. The Ohio Agricultural Experiment Station reports an experiment in which fertihzers were applied in arbitrary quantities in comparison with plats on which " the three fertilizing elements, nitrogen, phosphorus, and potassium, are given in approximately the same ratio to each other in which they are found in the plant." ^ TABLE XXVIII Fertilizer Tests with Continuous Corn Culture at the Ohio Agricultural Experiment Station. Average for Sixteen Years, 1894-1909 Plot No. Febtilizinq Materials Pounds per Acre Yield Increase Grain Bushels Stover Pounds Grain Bushels Stover Pounds 1 2 3 4 None fAcidphos. 1601 ,..„„, Mur. potash 100 "^'*J?:'^ lNitratesodal60j'''^*°*'*y f Acid. phos. 60 ] ratio ■ ,Mur. potash 30 in com I Nitrate soda 160 J plant None . . .... 22.22 42.71 34.95 17.46 1441 2326 1946 1248 22.08 15.90 949 634 The ratio between the elements in the two mixtures and that required by the plant is shown in the following state- ment : — : 1 Ohio Agr. Exp. Sta., Circ. No. 104 •" 3. 1910. 140 CORN CROPS Arbitrary mixture Ratio . . Natural proportion .... Ratio ... Elements required for 40 bushels corn Ratio . . . NrrEOQEN Pounds 24 _6 24 JB 59 6 Phosphobic Acid PotTNDS 24 8 2^ 21.2 2 Potash Pounds 60 12 15 j| 34.0 3 The arbitrary mixture had approximately three times the phosphoric acid and potash in proportion to nitrogen that the natural proportion showed. In this case the arbitrary mixture gave the best results, as the crop was able to obtain nitrogen from the soil to balance the fertilizer applied. The point is well illustrated in a second experiment in which the fertilizer mixtures were compared. The fertilizer was applied to corn in a three- year rotation of clover, corn, and wheat. A part of the benefit of the fertihzer went to the wheat and clover. Results with all three crops are given on the following page. Plot 19 received a smaller application of fertilizer at less cost, yet it contained twice as much phosphorus, which seems to be the one element that this soil most required. The above table emphasizes that the corn grower should handle nitrogen, phosphorus, and potassium more or less independently, adjusting his fertihzer application to the needs of the soil. The ready mixed fertilizer will not ■usually be as profitable as the fertilizer mixed especially for the case concerned. MINERAL MATTER FOR CORN LAND 141 TABLE XXIX Showing Fertilizers applied in Certain Experiments at THE Ohio Agricultural Experiment Station in a Three- years Rotation op Clover, Corn, and Wheat i Plat Fertilizer Pounds of Elements APPLIED per Acre Cost Pounds per Acre Nitro- gen P2O5 K2O Acre 17 18 19 20 None [Nitrate soda 160 Acid phos. 80 IMur. potash 80 Ratio . . . [Tankage 100 Acid phos. 80 IMur. potash 10 None Approximate rati (See table.) in plant 24 7 7 7 12.8 4 23 2.5 40 11 5 4 $7.45 $2.30 Corn, Twelve Crops Average Annual Increase per Acre Value Plat Grain BuHliels Stover Pounds Corn Grain Busliels Twelve Crops Stover Pounds Wheat Grain Busliels Twelve Crops Straw Pounds Hay Pounds Cost of Treat- ment OP In- creas:e PER Acre 17 18 19 20 36.55 43.12 44.37 34.09 2303 2587 2456 2025 9.25 10.50 471 348 2.83 4.07 309 510 599 718 $7.45 $2.30 $9.37 $11.36 ipp. 17-18. 142 COBN CROPS FERTILIZER MIXTURES FOR CORN 100. To mix the fertilizer so as to suit the requirements of the particular soil and crop, is the ideal way. As a basis for use when the fertilizer requirements are not known, general experience indicates that a formula of about 3-8-5 will most often be satisfactory. The Maine Agricultural Experiment Station ^ suggests the following formula : — TABLE XXX Formulas fob Febtilizbbs suggested bt the Maine Agri- CULTUEAL Experiment Station Chop and FEBTILIZI^fQ Material Weight Used Pounds NrrBO- GEN Pounds Phos- phoric Acid AVAII/- ABLB Pounds Potash Pounds Corn on sod land, or in conjunction with farm manure. Nitrate of soda Acid phosphate ... . . Muriate of potash 100 400 150 16 52 75 Total Percentage composition . . . Nitrate of soda Screened tankage Acid phosphate Muriate of potash 650 100 200 300 150 16 16 11 52 8.0 15 39 75 11.6 75 Total Percentage composition . . Nitrate of soda Cottonseed meal Acid phosphate Muriate of potash 750 100 200 400 150 27 S.6 16 14 54 7.2 52 75 10 4 75 Total Percentage composition . . . 850 30 S.5 62 6.1 79 9.S 1 Maine Agr. Exp. Sta., Bui. 107. 1904. MINERAL MATTER FOB CORN LAND 143 Director Charles D. Woods, who prepared the above formulas, makes the following statement in connection therewith: "Corn is a crop that uses a large amount of nitrogen. It is usually grown upon sod land or with farm manure, or both. Indeed, it is doubtful if, under ordinary- conditions, it would prove a profitable crop to be grown on somewhat exhausted soil with commercial fertilizers alone. . . . The first formula contains only about one- sixth of the nitrogen needed to grow the crop. With a good sod and especially with a liberal dressing of farm manure, that will be all that is needed. The second and third formulas carry more nitrogen. ..." 101. The New York (Geneva) Agricultural Experiment Station ' suggests the following formulas for corn : — TABLE XXXI Pounds of Different Constituents FOE One Acre FOBMCLA Principal Soiirce of Principal Source of Principal Source of Potash Nitrogen Phosphoric Acid 1 60 to 100 lb. ni- 350 to 700 lb. 60 to 120 lb. trate of soda bone meal muriate of potash 2 50 to 100 lb. 250 to 500 lb. 60 to 120 lb. sulphate of dissolved sulphate of ammonia bone potash 3 100 to 200 lb. 300 to 600 lb. 250 to 600 lb. dried blood dissolved rock kainit 4 3000 to 4000 lb. 600 to 1200 lb. stable mantire ■wood ashes Pounds per Nitrogen 10 to Available phos- Potash 30 to 60 acre . . 20 phoric acid 35 to 70 Percentage 2 7 6 » N. Y. (Geneva) Agr. Exp. Sta., Geneva, N.Y., 14th Rept. 144 CORN CROPS 102. As soils are continuously cropped, progressive changes take place. A suggested method of adapting the fertilizer to conditions is given by C. E. Thome of the Ohio Agricultural Experiment Station, as indicated by experience on rather poor glacial soil at that station : ^ — TABLE XXXII Fertilizers suggested for Different Conditions Percentage Composition Conditions Ammonia Phosphoric Acid Potash For crops immediately follow- ing clover For crops one or two years after clover For crops two or three years after clover For crops on exhausted soils . 1 3 4 6 13 12 12 12 2 3 4 6 WHEN IT PAYS TO FERTILIZE FOR CORN 103. The gross income per acre from cereal crops is low, and their extensive culture can be carried on only where the soil naturally furnishes most of the mineral elements without excessive cost. In the past, cereal culture has largely followed the opening up of new lands, while it has declined on old soils when extensive use of commercial fertilizers has become necessary. From the foregoing discussion it seems that the use of mineral fertilizers for corn can be applied at a profit only as a supplement to soils already well supplied with avail- able minerals. In many cases when a single mineral 1 Ohio Agr. Exp. Sta., Bui. 141. 1903. MINERAL MATTER FOR CORN LAND 145 element is lacking in an available from, this element may often be directly supplied at a profit; but ordinarily, in order to obtain the highest availability from the min- erals, fertilizers must be used in connection with barnyard manures, and in a properly balanced crop rotation where most of the nitrogen is supplied by legumes and the soil is kept well supplied with decaying organic matter. A review of the experimental evidence regarding the use of commercial fertilizers for corn seems to justify the following principles. 1. It seldom pays to use mineral fertilizers alone on land in a low state of fertility or on land that would not produce more thaii 20 bushels of corn per acre under favorable conditions.' 2. Even on good land it seldom pays to apply mineral fertilizer alone directly to the corn crop.^ 3., It seldom pays to use fertilizers where corn is grown continuously or where it is rotated with grain crops only. Under such conditions, according to the Ohio station, only 60 per cent of the fertilizer is recovered in the crop.' 4. Commercial fertilizer pays, as a rule, only when used in connection with a rotation where manure or a legume crop, or both, are plowed under.^ In this case it is usually best to apply the fertilizer to the sod land, or, when wheat is grown in the rotation, a part maybe applied to the wheat. The above expecially applies to phosphates and potash. Sodium nitrate is a partial exception to the above general rule, as it is sometimes applied with profit to the growing corn. 1 XT. S. Dept. Agr., Farmers' Bui. I44 : 10 ; Farmers' Bui. 414 : 12. 1910. R. I. Agr. Exp. Sta., Bui. 113 : 113. 1906. 2 Ind. Agr. Exp. Sta., Bui. 77 : 32. 1899. ' Ohio Agr. Exp. Sta., Bui. 110 : 68. 1899. * U. S. Dept. Agr., Farmers' Bui. lU : 10. 1901. L 146 CORN CHOPS Special cases : There are exceptions to the above rules, a striking example of which are certain rich muck lands in lUinois, well supplied with all elements except potassium, where an application of potassium salts pays large returns.' It is not to be inferred that fertilizers do not afford a stimulus and give increased production, for they do ; but the gross income from an acre of com is not sufficiently increased to pay the cost of fertilizer, except in certain cases when used in connection with manure and legumes. This makes it apparent that profitable com growing must be carried on as a part of a general farming scheme in which the soil fertility is principally maintained by the use of green manures or barnyard manure, which may be supplemented in a limited way with commercial fertilizer. NITROGEN 104. A large or excessive supply of available nitrogen is not considered favorable for most of the cereals, as wlieat, oats, or barley; the effect being to produce an excessive growth of straw, and often a decreased yield of grain. Corn, however, is not so affected, and is most productive on heavily manured land or on newly drained alluvial or swamp lahds where the available nitrogen is so abundant that wheat or oats would " run to straw " and produce little or no grain. In fact, a well-manured clover sod where available nitrogen is in greater excess than any other necessary element is ideal corn land. A large supply of nitrogen has sometimes been found a disadvantage early in the season, as it may stimulate a growth of plant too large to be adequately maintained during the remainder of the season. For example, the > Hopkins, C. G. Soil Fertility and Permanent Agriculture, p. 471. MINERAL MATTER FOR CORN LAND 147 " Williamson " ^ method of corn culture advocates the withholding of soluble nitrate fertilizer until the plants are six to eight weeks old, thus tending to retard stalk growth but to give the needed stimulus at the time when ears are forming. West of the Missouri River, where the soil is loose and nitrification begins early in the season, it often happens that on very fertile soil a vigorous spring growth is stimu- lated, and later, if the season proves unusually dry, the growth cannot be sustaineid; and such fields suffer more than do fields in a less fertile condition. On the other hand, with abundant water supply those fields would have been more productive. LIME 105. Lime is an essential element required by plants. It is not commonly applied as a fertilizer, as only about 12 pounds of lime are required by a 50-bushel corn crop, and most soils are abundantly supplied in so far as having sufficient lime for plant growth is concerned. The most important use of lime is as a soil amendment, when it assists in several ways in making the soil more favorable for plant growth : — 1. Acid in the soil is neutralized. 2. Potash and phosphate in the soil are made more readily available. 3. Organic matter decays more rapidly and the organic nitrogen and minerals become available to plants in less time. 4. The soil is made a more favorable medium for bene- ficial bacteria forms. 1 The WilUamson Plan. S. C. Agr. Exp. Sta., Bui. 135. 1908. 148 COBN CEOPS 5. The mechanical condition of heavy clay soils is improved. According to Bulletin 64 of the Bureau of Soils, United States Department of Agriculture, one hundred sixty-eight experiments with lime for corn have been reported by experiment stations. The average increase reported is 3.2 bushels per acre at a cost of $8.91 for the lime. For corn soils in general hming would not pay, but, on the other hand, certain experiments show large profits from the use of lime. The Tennessee station reports an increased yield, at less cost per bushel, than for any of a number of mineral fer- tilizers tried in comparison, as shown in the following table : — TABLE XXXIII Fertilizers with Hickory King Corn, 1901-1902 Cost of Fbhtilizer PER Acre Yield per Increase Cost per Fbktilizer Used Amount Acre of Grain Due to Fertilizer Bushel OP Bushels Bushels Increase No fertilizer . 41.94 Farmyard manure . . 8 tons $3.20 48.71 6.77 $0.47 Lime . . . 25 bushels 1.50 49.22 7.28 .10 Nitrate of 100 soda . . pounds Acid phos- 150 phate . . pounds 4.00 43.97 2.03 1.74 Muriate of 5 potash pounds At the Ohio station ' the addition of Hme increased the 3deld of corn 10 bushels per acre, or about 30 per cent, both 1 Ohio Agr. Exp. Sta., Bui. 159 : 173. MINERAL MATTER FOR CORN ZAND 149 on plats where lime was used alone and where it was used in connection with other fertilizers. In commenting on results with lime, Director Thome says : — " Taking the results as a whole, it would seem that the lime has performed two distinct offices in this test : in the first place, it has increased the yield by an average of about 10 bushels per acre, or 30 per cent of the unfer- tilized yield. This it must have done in one or both of two ways ; either it has furnished a needed element of plant food to the growing crop, or else it has rendered the plant food already in the soil more available, either by direct chemical action of the lime itself on the soil stores of nitro- gen, phosphorus, and potassium, or by opening up the soil and giving the air, water, and frost a better opportunity to reach these stores and prepare them for plant nutrition. " The other office performed by the lime seems plainly to have been the setting up of conditions favorable to, the growth in the soil of the micro-organisms by which the stores of organic nitrogen are gradually converted into available form through the process of nitrification. This is indicated by the fact that the giving of large quantities of available nitrogen in the fertilizers appears to have reduced the effect ascribable to lime, whereas this effect seems to have been augmented by fertihzers containing little or no nitrogen." It may be said in general that lime as a soil amendment is more likely to be beneficial on heavy clay soil, in humid regions, where aeration is poor and the products of organic decomposition are very likely to be toxic to plants. In regions of low rainfall or sandy soils, lime is not so likely to be required as a soil amendment. There are various chemical tests for determining the probable lime requirement of a soil, but the most reliable 150 COBN CBOPS test is to apply lime experimentally and note results for at least two years. Eef erences on fertilizers : — VooRHBBs, E. B. (1898.) Fertilizers. Lyon and Fippin. (1909.) Soils, pp. 267-386. Bailey, L. H. (1911.) The Farm and Garden Rule Book, . pp. 40-91. Hopkins, C. G. (1910.) Soil Fertility and Permanent Agri- culture. Ohio Agr. Exp. Sta., Bui. 141 ; Circ. 104. Maine Agr. Exp. Sta., Bui. 107. Vt. Agr. Exp. Sta., Bui. 116 ; Giro. 7. References on lime : — Agriculture Lime. Conn. (Hatch) Agr. Exp. Sta., Bui. 163. Lime and Liming. R. I. Agr. Exp. Sta., Bui. 46. Chemical Methods of Ascertaining Lime Requirements of Soils. R. I. Agr. Exp. Sta., Bui. 62. Liming Acid Soils. U. S. Dept. Agr., Farmers' Bui. 133. Liming the Soil. Ohio Agr. Exp. Sta., Bui. 159. Carriers of Lime. Ohio Agr. Exp. Sta., Circ. 123. The Rational Use of Lime. Mass. Agr. Exp. Sta., Bui. 137. Increasing the Yield of Corn. Tenn. Agr. Exp. Sta. Bui., Vol. XVII, No. 2, p. 46. The Use of Lime upon Pennsylvania Soils. Penn. Dept. of Agr., Bui. 61. 1900. CHAPTER XV REGULATING THE WATER SUPPLY A 50-BUSHEL corn crop requires 7 to 10 inches of water for the use of the plant, "besides that to be allowed for run-off, seepage, and evaporation. In Nebraska, with a 29-inch rainfall, the division of this water between the four sources of losses is estimated as follows, when a 50- bushel crop is grown : — Water required by tlie plants 8 inclies Water lost by run-off 3 inobes Water lost by seepage 2 incbes Balance lost by evaporation 16 inches Total 29 inches The proportion of total rainfall lost by the different means will vary with the region, but it is probable that in most cases evaporation is twice the amount required by the crop. 106. Not all evaporation is undesirable. Whenever the soil reaches its water-holding capacity, as is often the case in early spring, then it must be dried by evaporation before cultivation can be practiced. Run-off is desirable after the soil reaches saturation, if the run-off takes place in such a way as not to cause erosion, since the taking up of this water by the soil would increase the loss by drainage, and excessive drainage means a slow leaching of the soil. The amount of run-off necessary in order to care for ex- cessive rainfall, or of evaporation necessary in order to dry out the soil, will vary with the rainfall. In fact, all the water above that actually used by the crop is exces- 151 152 CORN CROPS sive and must be disposed of in some way, as by drainage, run-off, or evaporation. Even though the crop requires a relatively small pro- portion of the total rainfall, the crop often suffers due to the fact 'that this small proportion is required during a com- paratively short period and in excess of the water-storing capacity of the soil. Lyon and Fippin' give the following statement regarding the water-holding capacity of some soils : — TABLE XXXIV Wateb Capacitt Amount of Available Water Minimum Per Cent Maximum Per Cent Per Cent Cu. in. per Cu. ft. Inche3 per Acre, 4 ft. Light sandy loam . . Silt loam . . Clay . . . 3 15 23 8 25 40 2 6 10 17 122 218 274 3.4 6.0 7.6 Studies at the Nebraska station indicate the water requirements of a 50-bushel corn crop for the different months to be about as follows : — TABLE XXXV Inches January 1 to June 1 June . . . . July August ... September .... October 1 to January 1 Total .... .00 .50 3.60 3.30 .60 00 8.00 ' LtOn and Fippin. Soils, p. 158. 2 Assumed. REGULATING THE WATER SUPPLY 153 Most of this water is required during a period of five or six weeks, ranging from about July 10 to the end of August. On p. 65 it was pointed out that evaporation from the soil and loss from run-off probably equals or nearly equals the requirements of the plants in making a 50-bushel crop, or the total requirement by the crop, and evaporation from the soil, etc., for July and August probably amounts to 12 inches. This is twice the storage capacity of the soil and perhaps three times the amount usually available early in July. After the water stored in the soil is ex- hausted, if rains are delayed, the crop suffers, being greatly reduced, and this often happens even when abun- dant rains come later. The seasonal requirements of corn are illustrated by Fig. 24. 107. Three ways are open for regulating the water supply : (o) increasing the water-holding capacity of the soil; (6) conservation by preventing evaporation; (c) decreasing run-off during the growing season. Since the water-storage capacity of soil is closely related to its physical composition, little can be done to improve this condition in a practical way. The addition of vege- table matter helps only to a limited extent. A certain amount of evaporation can be prevented by cultivation, but how much has never been satisfactorily determined under field conditions. It is probable, how- ever, that loss by evaporation of water that has reached a depth of 12 inches in the soil is very small, and that culti- vation serves principally to prevent evaporation of mois- ture from rains that penetrate no deeper than 6 to 10 inches. Experimental results under field conditions to show the effect of cultivation give extraordinary variation. For example, at the lUinois Agricultural Experiment Station, plats of corn that were not cultivated but merely 154 COBN CROPS had the weeds shaved off gave as good results as an aver- age of five years as when carefully cultivated, and similar results have been secured at other stations. (See p. 206.) On other occasions cultivation has apparently conserved sufficient moisture to improve the yield. The underlying principles have not been clearly worked out. It seems apparent that a well-cultivated surface, with a good store of organic matter, will take up a moderate rain more readily and store a large percentage of it deep enough to protect from surface evaporation than will a hard and uncultivated surface ; also, that when this mois- ture is stored continued cultivation will decrease the rate of loss from the upper 10 inches of surface. EEOSION 108. Effect of erosion. — Erosion affects the agricul- tural value of land in the two ways : first, by producing gullies and large ditches, thus increasing the expense of crop cultivation and resulting in the actual loss of some land; second, by reducing available fertility, through removing the surface. In the latter case, the damage to productivity depends on the soil. In heavy clay soils, much of the available fertility seems to be in the surface 6 inches. On such soil productivity is often reduced for many years by turn- ing up too much subsoil at one time with the plow. On the other hand, as pointed out by King,i in many regions, especially of low rainfall, the subsoil, even to several feet deep, is as productive as the surface soil. In a case of such surface, erosion would work little or no damage. However, in most of the regions where erosion is severe, ' King, F. H. The SoU, p. 29. BSGULATING THE WATMB SUPPLY 155 as in eastern United States, the soil is heavy in texture, the exposed subsoil not productive, and the loss of surface soil causes serious damage. When manure, mineral fertilizer, or lime is used, much of this added material remains in the plowed surface and erosion causes a direct loss of this material. 109. Causes of erosion. — In the corn-growing area of the United States — ■ that is, from the Atlantic Coast westward to the 100th meridian — erosion is related to the amount of run-off water and to the condition of the soil at the time the run-off takes place. In the principal corn-growing States, north and west of the Ohio River, erosion is not serious. The land is generally level and rainfall not excessive. Also, during a part of the year the ground is frozen, and in June, July, and August, when about 40 per cent of the rainfall occurs, the land is in crop. From Ohio eastward, however, the rainfall is heavier and cultivated land is more rolling, thus increasing the total run-off and erosion. From the western edge of the Corn Belt to the Atlantic Coast, erosion gradually increases. In Kansas and Nebraska, with level farming land, the rainfall is 25 to 30 inches and the total run-off about 3 inches. In the North Atlantic States rainfall is heavier, land more rolhng, and the run-off is estimated at 40 to 50 per cent of the rainfall, which often amounts to a run-off of 20 inches or more. In the Southern States the most serious erosion takes place during the winter months. The soil is not frozen, is without a crop, and heavy rainfall occurs during this period. The relation of cropping systems to erosion may be grouped as follows : — (a) Land in grass erodes least. (b) Land in stubble or small grain erodes more than (a). 156 CORN CROPS (c) Land in cultivated crops erodes more than (6). (d) Cultivated land not in crops erodes most. 110. Preventing erosion. — Since the character of the crop and the grade of the land both have a marked effect on the degree of erosion, they are the two principal means of preventing the same. Land subject to severe erosion should be kept principally in grass crops and small grain, and never left longer than necessary without a growing crop. If a good supply of vegetable matter is maintained and deep plowing practiced, cultivated crops can often be grown on rolling land with little loss by erosion where otherwise the loss would be severe. It is often noted that new land just brought under cultivation does not erode, but as the humus supply decreases, erosion increases. Also, the plowing undsr of a heavy coat of barnyard manure or a green manure crop will often stop erosion where it is otherwise serious. Deep plowing enables the soil to take up water readily and give it up slowly, and in many cases deep plowing alons has been found to entirely prevent erosion. The second method of preventing erosion is by decreas- ing the grade. This is usually done by terracing, causing the water to follow the contour of the hills at a low grade. The same effect is secured in some degree by plowing and planting with the contour of the hills. To summarize : Erosion is better controlled when the land is in grass or small grain than when in a hoed crop. Sufficient organic matter and deep plowing decrease erosion. The land should not be left bare. The grade can often be decreased by terracing. The most serious loss due to erosion is the constant re- moval of the accumulated organic matter of the surface soil. BEGULATING TEE WATER SUPPLY 157 DRAINAGE 111. Corn requires a thoroughly drained soil, both be- cause it flourishes in a " warm " soil, and because it re- quires large amounts of available nitrates when making its rapid summer growth. On poorly drained land, even when such land is rich bottom soil, the corn plant will often have a yellow color indicating a need of nitrogen. Fig. 40. — Plan of ridging land for surface drainage. Two rows on each ridge. The water-logged soils interfere with bacterial activity and the normal nitrifying processes are prevented. Sur- face drainage for corn on very flat lands is often provided by plowing in narrow beds, 8 feet wide, and planting two rows of corn 4 feet apart on each bed. Underdrainage is so thoroughly discussed in several soil texts that it is not necessary to take up the subject here. SECTION IV CULTURAL METHODS CHAPTER XVI PREPARATION AND PLANTING So far in this book it has been the plan to discuss the fundamentals relating to the nature of the corn plant, its requirements, the conditions that must be met in the grow- ing of corn, and methods of modifying the plant to im- prove yield or quality. Having considered the above problems, the next step is to consider cultural methods. The basic principle in cultural methods is largely protection of the crop against unfavorable conditions that may arise, as draught, weeds, insect or parasitic enemies. The cultural method to be adopted in a particular case is the one that most effec- tually insures the crop, and at the least cost. Cultural methods must vary with the local situation. In regions of high priced labor and level lands, extensive systems have been developed. In regions of low priced labor and small fields more intensive methods are prac- ticed. The other crops to be grown, the character of the climate, the use of the crop, and many other factors all help to determine the most practical method to be adopted. As with other farm problems, the farmer him- self must largely determine the cultural method to be used on his own farm. THE OLD CORN STALKS 112. In the corn-belt and the Southern States, corn stalks are not harvested, but stand in the fields, to be plowed M 161 162 CORN CROPS under the following spring. In the early days of com culture in the middle west, the corn stalks were usually burned. The common custom was to break down the frozen stalks with a log or an iron rail and later when the groimd had thawed, they were raked with horse rakes into long windrows, and burned. For a week or two in each spring, the sky would be lit up every night by the FiQ. 41. — Two-row stalk-eutter. great burning fields of corn stalks. This so rapidly re- duced the organic matter in the soil that it soon became necessary to plow the stalks under, as is now the general custom, in order to obtain humus. To prepare for plowing, the stalks are broken with a rail, as before, and then usually gone over with a sharp disk, to cut them up. The stalk-cutter is also in general use. This implement has heavy revolving cylinders set with knives that cut the stalks in twelve inch lengths. Where the stalks are heavy it is more satisfactory than the disk harrow, although the stalk-cutter is often followed also with a disk-harrow. PREPARATION AND PLANTING 163 TIME OF PLOWING 113. When land is fall-plowed it is exposed more com- pletely to the action of frost, thus giving a finer state of pulverization. This is often an advantage with heavy soils, but in light soils it may actually be a disadvantage. Also, when a cover crop is to be turned under, there is more time for decomposition when turned under in the fall. When the soil is infested with the larvae of injurious insects, fall plowing just as freezing weather begins will often destroy many of these. For early planted crops there is not always enough time for proper preparation of all the land in the spring, and it is good farm management to do part of the plowing in the fall. Early spring plowing for corn, compared with late spring plowing, has not been the subject of extensive investigation. An experiment carried for a single season by Quiroga,^ at the Ohio State University, showed an increase of about 7 per cent in the crop with early spring plowing overlate, and a marked increase in avail- able nitrogen was found in the early plowed land through- out the season. DEPTH OF PLOWING 114. From experiment stations some twenty-six tests have been reported on deep and shallow plowing for corn. These results cannot be regarded as very significant as a guide in specific cases, since the results were obtained under a great variety of conditions. They may be sum- marized as follows : — Favorable to deep plowing 14 Favorable to shallow plowing 6 Indifferent results 6 ' QuiROQA. Ohio State TJniv. Bui., Series 8, No. 28, 164 COBN CROPS There are no experiments to show the ultimate effect of following a system of continuous shallow plowing or continuous deep plowing, but practical experience has shown that land should be occasionally plowed deep (8 inches) to keep the sm-face in best mechanical conditions. Heavy soil requires deep plowing more often than do light soils. Probably a very heavy soil J m wm li^ n \' -'■-'-,: f " '^'i .vS Fig. 42. — Plowing under alfalfa sod in preparation for corn. should be plowed deep once each year, while certain light soils, especially where rainfall is low, do very well with deep plowing every two or three years. Hunt 1 summarizes certain experiments with deep and shallow plowing as shown on the following page. It has been demonstrated many times, that if the soil has been kept in a good productive condition, that the preparation immediately before planting or even the system of cultivation after planting is not likely to have an important effect on the yield of the current crop. The crop secured does not depend so much on treatment of ' Hunt, Thos. F. Cereals in America, p. 220. PREPARATION AND PLANTING 165 soil for the present crop, so much as the kind of treatment it has had for the last ten or twenty years. The kind of treatment to be recommended must consider more the future -welfare of the land, than present benefits to be derived. TABLE XXXVI Yield op> Coen in Bushels Depth of Plowing Inches Station 2 i 6 8 10 13 Illinois 52.9 69.4 69.3 71.7 Illinois 54.0 57.5 56.0 Indiana (average 3 41.8 42.0 years) 39.5 40.6 42.3 Pennsylvania (average 3 years) 47.0 62.0 57.5 V58.5 New Hampshire ^ . . 14.2 26.2 29.4 28.2 Alabama 24.1 24.2 Minnesota .... 65.8 64.4 59.5 2 Ohio' 43.1 42.9 , Nebraska 38.5 31.0 1 Tons of green silage. Depths were 3, 5, 7, and 9 inches. ' Also subsoiled 6 inches deeper. ' Depths 3 and 7 inches. So far as tillage is concerned, as a factor in maintaining crop production, the following principles may be set forth : That all land should occasionally be plowed 8 to 10 inches deep. On heavy land about once a year, but on lighter soil, and in rather dry regions, once in two or three years being sufficient. The plowing should be done when the land is in proper condition to pulverize. Quite thorough treatment with pulverizing tools, as 166 COBir CROPS harrows, rollers, and cultivators, is essential to keeping the soil in. good mechanical condition. SUBSOILING 116. The subsoiler is a tool for loosening the subsoil without bringing it to the surface. While tools for this purpose have been in use for many years and have been generally tried out in all the principal agricultural regions, yet subsoiling is nowhere in general practice. General experience has confirmed results obtained at the Nebraska station, where, in a cooperative test with fifty-nine farmers for three years, beneficial results were obtained on soils having a heavy or impervious subsoil, but on loam sub- soils the results were indifferent or injiu-ious. PEEPAKATION OF PLOWED LAND 116. The amount of fitting that must be given to land after plowing depends on the soil and the seasonal condi- tions. A good loam soil, plowed when in just the proper condition, may need very little fitting with the simplest tools, as harrow and float, in order to bring it to a proper mechanical condition. On the other hand, the same soil if plowed when too wet, or if when wet it had been tramped by stock in pasturing, would require more labor and a greater variety of tools for proper fitting. This emphasizes the importance of plowing only when the soil is thoroughly pulverized by the plow. Also, further pulverizing of the soil, with harrow or cultivator, is most easily accomphshed within twenty-four hours or less after plowing, and one harrowing at this time may accomplish several times as much as a few days later, when the clods have dried. There are certain heavy clay soils that always require a PREPABATION AND PLANTING 167 great deal of fitting for good results. The best tool for pulverizing to a depth of several inches is the disk-harrow Where the land is stony or hard, a cutaway is more effec- tive. On very stony or rough land, a spring-tooth is more practicable than the disk, or the ordinary cultivator can also be used to good advantage. For surface finishing, the spilce-tooth harrow and weeder are used for pulverizing and the board drag and roller for further redi^ction. Repacking the soil after deep plowing is an important function of all tillage in preparing the seed-bed. When the Fig. 43. - - A modern disk-harrow. A tool that pulverizes the surface and packs the subsurface at one operation. plowing is done long in advance, so that heavy rains may come, little attention need be given to repacking. A fairly compact seed-bed is desirable at planting time, though not so important with corn as with wheat. A good method of repacking a loose seed-bed is to use either a subsurface packer, or quite as well a disk-harrow, set straight (no angle to disks) and loaded with sufficient weight to cut nearly through the furrow slice. These tools will pack the bottom of the furrow slice. To pack 168 COBN CROPS the surface, a roller or a smoothing harrow, or both, may- be used. Clearing of weeds is important in preparation. One principal advantage of early plowing is that more weeds may be germinated and destroyed before planting. While weeds are germinating rapidly, it is often an advantage to delay planting until the land can be entirely cleared, as it is much easier to destroy weeds before planting than after- ward. To sum up, it is important to plow the land when in just the right tilth for plowing, to pulverize thoroughly to repack when the seed-bed is loose, and to destroy weeds before planting. PLANTING THE SEED METHODS 117. (1) The seed may be " surface" planted, the land being prepared level and the seed planted in rows 1 to 3 Fig. 44. — Combined lister plow and drill. inches below the surface. (2) The planter may have a furrow opener, usually a pair of disks which open up a shallow furrow, the seed being planted in the bottom of this. (3) A lister may be used, which is essentially a double-moldboard plow throwing a furrow slice each way. The land is furrowed as deep as possible with the Uster, the corn being planted in the bottom. PREPARATION AND PLANTING 169 Surface planting is the method in common use on all heavy lands or in regions where rainfall is plentiful, being the co m mon method in all the States east of the Missouri River. The " furrow opener," or disk planter, is also Fig. 45. — A combined lister and drill. The land is not plowed in prep- aration for listing. popular with many farmers, especially when it is desirable to drill, as in the growing of silage or fodder corn. The lister came into vogue about twenty-five years ago, but it is used extensively only where the soils are rather light in texture (loam or sandy loam) and in regions of rather Ipw rainfall. In central Nebraska, Kansas, and Oklahoma, one-half or more of the corn is listed. List- s I •I a «i p. a o o I s PBEPARATION AND PLANTING 171 ing is not practicable on land subject to washing, as the planting is likely to be destroyed by heavy rains. Also, in cold or wet soils the seed is likely to rot in the lister furrows, or growth of the young plants to be much retarded. Where listing is practicable, namely, in dry, warm soils, it is a very cheap method of producing corn, as the ground is not plowed before planting, though it is usually disked. Cultivation is simple and easy. SOWING CORN FOE FORAGE 118. For coarse forage or soihng, corn is frequently sown broadcast or drilled thick with a grain drill. One to two bushels of seed are sown per acre. Usually a rather small early variety is used, rather than a tall or late variety. Fig. 47. — Corn sown broadcast for forage. In above case was sown after ■ - wheat harvest. 172 CORN CROPS Early sweet com is well adapted for this purpose and is often sown in July after a small-grain crop has been har- vested. CHECKING AND DBILLING 119. When corn is to be surface planted it is usually " checked," that is, planted in hills and rowed both ways, thus permitting of cross cultivation. When corn is drilled on the surface, it is often difficult to keep weeds out of the Fig. 48. — A two-row corn planter. Will drop in hills, rowing both ways, or in drills. Commonly called a check-rower. row, as little soil can be thrown around the plants in cultivating. This difficulty is overcome in a large measure by using the furrow opener and placing the corn in a shallow furrow. TIME OF PLANTING 120. Many experiments have been made on the time of planting, but the principal conclusion may be stated as PREPARATION AND PLANTING 173 finding an average range of about six weeks for corn planting. The very earliest and the very latest plantings are usually not so successful as those about midseason. For example, the Illinois station in 1890 made plantings from April 28 to June 9. The average yield of the corn Fig. 49. — Special attachments for corn planter shoes. planted in May was 73 bushels per acre, while the average yield of the three remaining plantings, one in April and two in June, was 63 bushels per acre. Many experiments at other stations bear out the state- ment that there is a period of about three weeks for corn planting with equal chance of success, though there are occasional seasons when the very early or very late plant- ings are best. The optimum season is shorter in the North and longer in the South. TABLE XXXVII Time of planting Corn in Certain Regions' Reqion Beginning GeNEBAI/^ Ending Planting Febiod Days Gulf States ..... Central States (Virginia to Kansas) . . . Northern States (New York to Minnesota) . March 15 April 15 May 10 April 5 May 1 May 20 May 10 May 25 June 1 55 40 20 1 U. S. Dept. Agr. Yearbook, 1910, p. 491. 174 COBN CROPS The above table shows that the planting season begins about two months earlier in the Gulf States, as compared with the Northern States, but the total length of the plant- ing season is about three times as long. The average of the beginning of corn planting is also shown by the accompanying chart : — hiAyie Fig. 50. — Chart showing average date of planting corn in the United, States. The percentage of moisture in the crop at harvest time usually increases with the lateness of planting, after a certain date, as illustrated by the following data from the Illinois station : ^ — 1 111. Agr. Exp. Sta., Bui. 20. 1892. PREPARATION AND PLANTING 175 TABLE XXXVIII Data taken at Husking Time PotJNDS TO Percentage Bushels of Shelled Corn PER Acre Bushels of Date of MAKE One OF Moisture AlE-DRY Planting Bushel in IN Shelled Corn per Dry Cobn Corn Acre April 25 . . 69.9 14.0 52.6 60.8 May 2 70.8 14.6 52.6 50.4 May 9 70.9 14.8 50.7 48.5 May 16 74.4 17.0 53.3 49.7 May 23 80.0 19.3 57.9 34.1 May 30 96.8 24.0 40.0 37.5 June 8 97.9 23.9 43.9 37.5 June 13 127.8 31.5 25.2 19.4 DEPTH OF PLANTING 121. Corn is usually planted 1 to 4 inches deep. Re- sults from several experiment stations are summarized as follows : — TABLE XXXIX Planting Corn at Different Depths Yield per Acre in Bushels Planting Inches OhiQi Average 6 Years Indiana 2 Average 6 Years Illinois " Average 5 Years 1 2 3 4 5 6 56.6 51.2 46.8 38.6 39.2 37.8 28.8 78.0 72.0 65.0 69.0 61.0 60.0 1 Ohio Agr. Exp. Sta., Rpt. 1890: 87. 2 Ind. Agr. Exp. Sta.; Bui. 64: 5. 1897. > m. Agr. Exp. Sta., Bui. 31 : 353. 176 CORN CROPS In no case has the average yield been increased by plant- ing more than 2 inches deep. In heavy soils, such as of the Ohio station, shallow planting was decidedly better, while in loose loam soil, at the lUinois station, the depth of planting did not vary results so much. Also, when the soil is warm and dry the corn should be planted deeper than when the soil is cold. In two years out of seven at the Ohio station, when the soil was drier than common, the 3-inch plantings gave the best results. Some persons have thought that deep planting would estabhsh the roots deeper in the soil. It has been found, however, that the roots spread out at about the same depth, no matter what the depth of planting. Ordinarily the roots spread out about 1 inch below the surface. It would seem, then, there is no object in planting corn deeper than is necessary to insure plenty of moisture for good germination. RATE OF PLANTING 122. The customary rate of planting varies with soils and cUmate. In the South the corn rows are often 5 feet apart and the hills 4 feet apart, with two stalks to a hill. The rate of planting increases toward the North. Cus- tomary rates are as follows : — TABLE XL Region Distance Apart OF Hills Plants PER Hill Plants PER Ache Gulf States Middle States (Virginia to Kansas) Northern States (New York to Minnesota) 4' + 5' 3'8" + 3'8" 3'6" + 3'6" 2 2-3 3-4 4,000 9,000 12,000 PREPARATION AND PLANTING 111 The rate of planting is partly regulated by the size of plant. Plants in the Gulf States are about twice as large as in the Northern States, due in part to climate and also to the longer growing season. It has been shown, however, that for a given place the rate of seeding within wide limits does not have a marked effect on yield. An experiment regarding this point was conducted by the Illinois Agricultural Experiment Station.' Fig. 51. — A Southern method of planting on poor soils. Rows wide apart, and a crop of peanuts between. For soil improvement cowpeas are sometimes grown between. For three years corn was planted at rates varying from 5,940 to 47,520 kernels per acre. The maximum yield was obtained with 11,573 kernels per acre, though almost as good yields resulted when 15,840 or 23,760 kernels were 1 111. Agr. Exp. Sta., Bui. IS ; 410. 178 CORN CROPS planted. The average yields were 81, 77, and 76 bushels per acre, respectively. At the Nebraska station, corn was planted in hills 3 feet 8 inches apart each way, the stand varying from one to five plants per hill. TABLE XLI Average Results prom planting Cokn at Various Rates FOR Six Years (1903-1908), Nebraska Station i Plants PEB Hill Yield PER Acre Bushels Average Weight OF Ear Ounces NnMBER OF Eabb PEB 100 Plants NUMBEE OF TiLLEBS PEB 100 Plants Two- Eaeed Plants PER 100 Barren Plants PER 100 1 2 3 4 5 48.3 67.7 75.5 76.7 76.3 10.5 10.6 9.4 8.2 7.4 161 115 95 82 77 138 60 25 10 3 13.32 4.9 2.4 .8 1.1 3.0 4.8 6.9 8.3 10.8 ' Nebr. Agr. Exp. Sta., ^ Four years only. Bui. 112 : 30. 1909. There was practically no difference in yield when three, four, or five plants were grown to the hill. ADJUSTMENT OF CORN PLANTS 123. As the number of plants increased, the size of ear and the number of ears decreased, while the number of barren plants increased. One stalk per hill produced 64 per cent and two stalks per hill 90 per cent as much grain as did three stalks per hill, due principally to the increased size of ear and number of tillers producing ears and to the decrease in number of barren plants. It is evident that the corn plant is capable of a wide range of adjustment PREPARATION AND PLANTING 179 ECONOMIC VALUE OF TILLEKS 124. The question often arises as to whether tillers should be pulled when they appear in abundance. Data were taken at the Nebraska station for five years, and in every case the yield was decreased by removing tillers. For three years the corn was planted at different rates, the data being sununarized as follows : — TABLE XLII Effect on Yield op Grain op removing Tillers prom Corn Three-Year Average (1906-1908) Average Yield in Bushels PER Acre Average Yield of Stover in Pounds per Ache OF Plants PER Hill Tillers . on Tillers Removed Difference in Favor of Tillers Tillers on Tillers Removed Ini?rease Due to Tillers Per- centage Decrease Due to Removing Tillers 1 2 3 4 5 45.9 66.1 69.6 73.2 76.7 31.8 56.4 64.4 71.4 72.6 14.1 9.7 5.2 1.8 4.1 6,061 5,127 5,115 5,801 6,043 2,208 4,200 4,687 5,602 5,987 2,853 927 428 199 56 56.3 18.1 8^3 3.4 .9 Tillers appear to develop in response to the needs of the crop, in an attempt to bring the stand up to normal. When the stand is maximum, few tillers develop. The occasions are certainly very rare when it would pay to remove tillers. OTHER FACTORS AFFECTING PRODUCTION OF TILLERS 125. On some soils tillers do noi develop even when the planting is thin. When early growth is slow or retarded, 180 CORN CROPS as on heavy or cold clay soils, there is not sufficient stimu- lus early in the life of the plant to start the tillers. RATE OF PLANTING ON DIFFERENT SOILS 126. On good soils it is generally recognized that plant- ing should be thicker than on poor soils. This is shown by data obtained by the Illinois station. ^ In a series of tests on different soils, corn was planted in hills at various dis- tances apart and two or three stalks per hill. Grouping the data so as to include all fields yielding more than 50 bushels per acre in one class, and all yielding less than 50 bushels in the other class, the following results are obtained : TABLE XLIII Rate op Planting and Yield on Soils producing More or Less than 50 Bushels per Acre More than 50 Bushels pee Acre Less than 50 Bushels per Acre Region Two Kernels per Hill Three Kernels per Hill Two Kernels per Hill . Three Kernels per Hill Northern Illinois . . . Central lUinois . . . 67.9 59.8 68.5 62.8 41.4 43.2 42.4 40.9 Average .... 58.8 65.6 42.3 41.6 On productive soil the yield was increased by the thicker planting; but on the poorer soil two kernels per hill evidently furnished the maximum stand, as no further increase was secured by three kernels per hill. Data from the Indiana station show that in dry seasons the 1 m. Agr. Exp. Sta., Bui. 1^6: 366-377. 1908. PUBPABATION AND PLANTING 181 thin plantings give the best results, while in favorable seasons the reverse is true : ^ — TABLE XLIV Effect op Season on Yield and Percentage op Grain Seasonable, 1888-1891 Dry, 1893-1894 Stalks Ears Ears Inches Per- CENTAQE Per- Apart centage Bushels Pounds Bushels Com Stalks Corn Stalks 191 49.76 3,617 49.1 22.07 3,092 33.3 16 54.05 4,065 48.2 21.27 3,143 32.2 14 57.79 4,158 49.3 19.39 3,762 26.5 15 57.81 4,201 49.6 14.28 5,204 16.1 11 59.14 4,960 45.5 13.80 4,360 18.1 This also indicates that in semiarid regions, as central Nebraska or Kansas, the regular practice should be rather thin planting. METHOD OF DISTRIBUTION OF PLANTS 127. At the Illinois station, hill planting was compared with drill planting at various rates per acre. For example, four plants would be planted in hills every 48 inches, in comparison with two plants every 24 inches or 1 plant every 12 inches. The conclusion was that it made no difference in what manner the seed was distributed, so that approximately the same number of plants per acre were grown in each case. At the Nebraska station, a uniform distribution of three grains per hill was compared with distributing the 1 Ind. Agr. Exp. Sta., Bui. 64 : i. 18^ CORN CROPS seed in different amounts per hill but planting the same number per acre. The uniform distribution had a slight advantage, but not enough to indicate that the ordinary- variation in dropping in corn planters would materially affect the yield.' WIDTH OF ROWS 128. Width of rows is an important consideration, since the amoimt of labor required in planting and cul- tivating an acre is directly related therewith. TABLE XLV Distance Apart op Rows Feet Rods of Travel in Cultivating One Acre Percentage Increase in Labor 4.0 3.5 3.0 650 754 880 16 per cent increase over 4 feet 17 per cent increase over 3.5 feet 35 per cent increase over 4 feet Numerous experiments have not shown a practical advantage in having rows closer than 36 inches in the northern limit of corn-growing States, 42 inches in the central corn States, and 48 inches in the Southern States, when the standard type of corn for the region is grown primarily for grain. A small early variety may be planted closer. When the corn is grown primarily for silage or fodder, somewhat closer planting will give a greater yield of forage. . » Nebr. Agr. Exp. Sta., Bui. US : 35. PBEPABATION AND PLANTING 183 YIELD OF FORAGE 129. When yield of forage is considered, numerous experiments have shown that the yield of forage increases with the rate of planting up to a point about twice that required for maximum yield of grain. The following data illustrate : — TABLE XLVI Yield op Gbain and Stover when Cokn was planted at Different Rates. Three-year Average. Rows 3 Feet 8 Inches Apart. Illinois Station i Rate of Planting Kernels pek Acbe Bushels of Shelled Corn PER Acre Tons of Stover PER Acre Ratio of Shelled Corn TO Stover 5,940 9,504 11,880 15,840 23,760 47,520 55 72 81 77 76 59 2.5 2.9 3.0 3.1 3.7 4.8 100 : 160 100 : 140 100 : 130 100 : 140 100 : 174 100 : 290 1 lU. Agr. Exp. Sta., Bui. IS : 410. EFFECT ON COMPOSITION 130. The principal effect on composition when the rate of planting is increased is the change in ratio between percentage of ear and stalk. By referring to Table XLVI, last column, it will be seen that the proportion of stalk to ear increases as the rate of planting increases, there being more than twice the proportion of stover with the thickest planting as compared with the minimum ratio (11,880 kernels). The comparative analysis of stover and grain as summarized by Jenkins and Winton is given in the following table : — 184 CORN CROPS TABLE XLVII Composition of Stovee and Geain in Corn. Basis Watbr-fbeb NlTRO- Number Ash Photein Fiber GEN-FBEE Fat OF Per- Per- Per- Extract Peb- Analysis cent AGE centage centage Per- centage CENTAHE Fodder . . . 35 4.7 7.8 24.7 60.1 2.8 Leaves . . 17 7.9 8.6 30.6 51.0 1.9 Husks . . . 16 3.5 5.0 32.2 57.9 1.4 Stalks . . . 15 3.6 5.9 34.8 64.1 1.6 Stover . . . 60 5.7 6.4 33.0 53.2 1.7 Grain . . . 208 1.7 11.7 2.4 78.1 6.1 In well-developed corn planted at proper distance for maximum yield, the weight of shelled corn will be almost equal to the weight of stalk. Increasing the rate of planting has very little effect on the composition of either grain or stalk, but, as the proportion of stalk to grain increases, it is evident that the analysis of the whole plant will show a decreased percentage of protein and fat and an increased percentage of fiber. The total protein per acre, however, will increase. Silage from very thickly planted corn will not be so rich in percentage of protein and fat, but the total yield per acre will be greater. By reference to Table XLIV it will be seen that the rate of planting has more effect on percentage of ears in a dry season than in a seasonable year. The same would be true on poor soil. CHOICE OP A VARIETY 131. There are probably one thousand named varieties of corn. This very large number of varieties, many of 1 U. S. Dept. Agr., Office Exp. Sta., Bui. 77. 1892. PREPARATION AND PLANTING 185 which are of only local importance, makes rather confusing a study of experiments, in order to select the best varieties. In some cases a number of varieties have had a common origin and for a general discussion might be grouped to- FiG. 62. — Rough division of the United States into corn regions, accord- ing to the types of corn grown. gether. There are other groups, originating from widely different sources, which are yet very similar for all practi- cal purposes. The eastern half of the United States, where most of the corn is grown, may be roughly divided into large 186 CORN CHOPS regions, within which certain types and varieties pre^ dominate to a greater or less degree. Elevation must always be considered in selecting a type, For example, the coast plains of North Carolina would probably require a type similar to that suitable to the Gulf States, while the mountain regions would require a type 1 ^^^i ^^^H' 1 ^^^^^^V^^^^^^l |H| HviH fJH IKI^^V ''^HB^^^H I^^^^^^^H Kv-a i^^H ^^B ' ' 1 i^^^B i^^^V ^B ^^^^^^^^1 l^^^^^^^^^^^^l H\v ^^H ■ 'i^V^H I'l^^^H H^^^^^^^^^^H ^Kt\S m'lm f^f ^^M ■ ' ^^1 ill 1 ^^m ^HH V'!^! ^^K i^^^^^^^m' I^^^^^H ^■H ^^^^B ^^H 1 iVF^^H Fig. 53. — Prolific varieties of corn produce from two to six ears per stalk. They are adapted principally to the cotton belt. (Cockes' prolific.) PREPARATION AND PLANTING 187 normally adapted to a region as far north as Ohio. Thus, in North Carolina, above 2800 feet, flint varieties are recommended — the type of corn most common in the New England States. Other local considerations enter in, but in general the following varieties have been found satisfactory in the regions indicated : — Natural divisions Section No. 1. Gulf States. Prolific varieties bearing 160 to 200 ears to 100 stalks, on the average, give better results than those bearing only single ears. Among the best of these are : — Mosby Sanders Albemarle Cocke's Prolific Blount Marlboro Large-eared varieties are : — St. Charles White Boone County White Section No. 2. In this region large single-ear varieties share about equal importance with prolific varieties. In addition to the prolific varieties named above, we find such varieties succeeding as : — For good fertile land : — Boone County White St. Charles White Huffman White Pearl Learning' Hickory King For poorer soils and upland : — Hickory King Sanders Leaming St. Charles White (Early Strains) For high elevations : — Eight-row Fhnt 188 COBN CROPS This region partakes about half and half of the varieties common to the regions north and south of it. Section No. 3. This is the " Corn Belt." Only large single-ear dent varieties are grown. South of this belt the dent corn is mostly white in color, but in the Corn Belt yellow corn is as popular as white. The leading varieties are : — Yellow Learning Ried's Yellow Dent Riley's Favorite Legal Tender White Silver Mine Boone County White Johnson County White St. Charles White Early varieties Pride of the North Early Calico White Cap Leaming is probably the most extensively cultivated corn in the United States, being not only a universal favorite as a field corn, but also grown extensively for silage corn. Silver Mine is probably second in impor- tance. Section No. 4. This is more of the nature of a small- - grain region, but corn culture is increasing. A few years '■ ago flint corns predominated, but in recent years early dent corns have been developed and have largely replaced the flints. Dent varieties Pride of the North Minnesota No. 13 Wisconsin No. 7 Early Huron White Cap Section No. 5. Flint corns are grown principally, though on the best soils below 1000 feet elevation. The Flint varieties King Philip Smut Nose Eight-row Yellow Hall's Gold Nugget PREPARATION AND PLANTING 189 early dent varieties share about equal popularity with the flints. Above 1000 feet elevation, flints are almost universal. Flint varieties Eight-row and Twelve-row Yellow Flint King Phihp Canada Smut Nose Dent varieties Pride of the North White Cap Hall's Gold Nugget Various acclimated varieties local In this section, one-third to one-half of the corn is grown for silage. For this purpose the seed is usually Fig. 54. — Four ears in center are Sanf ord white flint, the longest type of cultivated corn. On right and left are shown typical ears of dent and flint, for comparison. 190 CORN CB0P8 purchased and large varieties are used that do not ripen grain but are barely mature enough for silage when frost comes. Leaming is the favorite with Hickory King, Eureka Ensilage, Burrill and Whitman, and Evergreen Sweet following. Iji fact, almost all the large dent varieties are used to some extent for ensilage on the lower elevations, while flints are grown on the higher lands. The importance of using acclimated seed has already been pointed out (page 117). Acclimated native seed should always be used for grain growing; and even for ensilage, while it is not necessary that the grain should mature, a better quality of silage is secured if the climatic change is not too great. PEEPAEING SEED FOE PLANTING 132. In the more humid part of the Corn Belt, corn is very likely to decrease in germination. This necessitates some precautions in curing the seed corn. In regions where the fall and winter climate is clear and compara- tively dry, there is less difficulty, but abnormal conditions occur often enough to justify special care of the seed corn as a regular practice. CAUSES OF POOE GEEMINATION 133. Slow or imperfect drying of the mature com, often accompanied with freezing, seems to be the prin- cipal cause of deterioration of vitality in the germ. When corn is first " ripe " the kernels will usually contain about 30 per cent moisture. This would be about September 15 to October 1 in the Northern Central States. If the weather is dry and favorable, the grain should dry down to about 20 per cent moisture in the course of four to six PREPARATION AND PI ANTING 191 weeks. If the climate is fairly dry, the corn should then remain in a good germinating condition either on the stalks or in good dry storage. The principal cause of loss in vitality seems to be failure to dry out properly upon becoming ripe. It is not necessary for the corn to be frozen to lose vitality, as it deteriorates at ordinary tempera- tures during the three months fol- lowing matiurity if not fairly dry. If freezing occurs, the loss is increased. A freezing tempera- ture occurring when the grain still con- tains a high per- centage of moisture may practically de- stroy vitality. Any cause that delays the proper drying of the corn after maturity will result in poor seed corn. In many cases, growers are using varieties too late in maturing or not well acclimated. Deep-kerneled types are more likely to lose in vitahty than shallow-kerneled corn. Varieties with large, sappy cobs are always slow in drying. Fig. 55. — Corn kernel split to show germ, which is the dark-colored body within the white, and extending nearly the length of the kernel. The main outer part of the germ is the Scutellum, secretes an enzyme that reduces the starch for use of young plant. The column-like body in the upper half is the Plumula, develops into young plant. The body at the lowest point is the Radicle, or root of young plant. 192 CORN CROPS STORING SEED CORN To insure good seed corn, the ears should be collected as soon as mature and dried. Methods of drying are discussed elsewhere. GERMINATION TESTS 134. If seed corn has been properly saved, there will be no occasion for making germination tests. It is much cheaper to save the seed properly than to make germina- tion tests. Whenever seed is to be selected from a supply, the quality of which is doubtful, careful germination tests should be made. The general test 135. A general test should be made first. Choose 100 ears at random and remove three kernels from each at different parts of the ear, as butt, tip, and middle. A good germinater is made by using two pie tins or dinner plates. Fill one with sand, sawdust, or soil. Place Fig. 56. — A simple germinater for testing seed corn. The corn is placed between damp cloths or blotters. a cloth on this and spread out the kernels to be germinated. Place a second cloth over the seeds and wet down. Then invert the second pie tin or dinner plate over the first so as to make a moist chamber within. Keep moist and in a warm place. Six days is sufl&cient time to allow for germination. If 90 per cent or more of the seeds show good strong sprouts, it is doubtful if it would pay to make a germination test of each ear separately. PREPARATION AND PLANTING 193 The ear test 136. When the preliminary test shows germination to be low or a high percentage weak, it will pay to germinate each ear separately. There are several " seed testers " on the market adapted for this work, but satisfactory germinaters can be made Fig. 57. — Making a germination test. The rack contains 100 ears, cor- responding in number to the squares in the germination box. at home. Usually a series of shallow trays are made and filled with sawdust or sand. A eloih. is laid on top marked off in two-inch squares, and each square is num- bered. Twenty inches square is a convenient size, though some prefer a tray twice to five times as large. The ears to be tested are laid out on shelves in sets of ten. The ears are then taken in order, six grains removed, and these grains placed in the corresponding square on the cloth, o 194 CORN CROPS It is well to take two kernels from the butt, two from the middle, and two from the tip, of the ear. When a tray has been filled, the grains are covered with a second cloth and a little sawdust on top and thoroughly wet down. When all trays are filled they are stacked up in a warm place and wet once a day for five or six days. All ears that have not shown a strong germination by this time should be discarded. IMPORTANCE OF STRONG VITALITY 137. It should be emphasized that only ears showing a strong, quick-growing germ should be used. C. P. Hartley records a typical experiment illustrating this point.' Fig. 58. —Difference in germination of ears. In each square are six kernels, each from a different ear. ' Habtley, C. p. The Seed Corn Situation. U. S. Dept. Agr., Bur. Plant Indus., Circ. No. 95. 1912. PREPARATION AND PLANTING 195 In November two bushels of seed corn were selected, one bushel being placed in a corn crib and the other in a dry seed room. Germination was about equally good in both cases, but the plants from the seed kept in the dry house were stronger and the yield averaged five bushels more per acre. GRADING SEED 138. The corn planter cannot be adjusted to uniform dropping of seed unless the kernels are uniform in size. •/ ^^;f ^;. '^^V^,> Fig. 59. — Three rows on left from single ear of good seed corn, rows on right from single ear of poor seed corn. Three Some growers sort the seed ears into two or three lots, according to size of kernel. In some cases " sorters " are used, consisting essentially of a pair of screens that take out both the extra large and the extra small kernels. CALIBRATING THE PLANTER 139. The dropping devices on planters are of three types, known respectively as (1) round hole drop, (2) round hole 196 CORN CROPS accumulative, and (3) edge drop accumulative. The first type represents the earliest type of dropper plate, when it was attempted to regulate the number of kernels per hill by the size of hole in the dropper plate ; the hole being large enough to take two, three, or four grains at a time. In both the accumulative drop forms, the hole Edge Dkop Fiat Dkop Fig. 60. — Two types of planter plates for dent corn. The edge drop is considered best where the corn is sorted to uniform size, and flat drop where the seed is not uniform. is large enough to take only one kernel at a time, the desired number of kernels being accumulated one at a time in a pocket and then dropped. The latter method is considered more nearly accurate when the seed has been well sorted. Before starting to plant, care sould be taken to see that the dropper-plate holes are of the right size for the seed used. CHAPTER XVII THE PRINCIPLES OF INTERCULTURE TILLAGE MACHINERY A GREAT variety of tools has been developed especially adapted for the tillage of corn. For the first cultivation of drilled or checked corn, the common smoothing harrow is often used. It is an excellent tool for this purpose as Peg. 61. — The weeder. A very useful tool on loose soil, for cultivating corn the first four weeks. Cultivates three rows at a time. it works a wide swath and kills young weeds effectively. One disadvantage is that it carries considerable trash es- pecially where there are many large com stubbs in the land. In this case the weeder is much better than the spike tooth harrow, as it clears of trash and does less in- jury to the young plants. When the weather is dry and 197 198 COBN CROPS the plants tough, a weeder may be used until the corn has reached the height of twelve inches. Fig. 62. — The simplest type of one-row cultivator, in extensive use throughout the corn belt. The corn cultivator has undergone a rapid evolution in the past fifty years. The first horse cultivators were single Fig. 63. — A modern riding corn cultivator, with handy adjustments and attachments, to readily adapt for all kinds of corn cultivation. Disk gangs attached. THE PRINCIPLES OF INTEUCULTURE 199 shovel plows, consisting of a very broad mold-board shovel mounted on a beam, with handles to guide. Later two narrower shovels were substituted for the single broad shovel. Though this was an improvement, it was still nec- essary to go twice in each row for thorough cultivation. Fig. 64. — Spring-tooth attachment. Fig. 65. — Shovel attachment. Fig. 66. — Cut showing angle and tilt adjustments. Later two of these double shovel plows were rigged on a two wheel sulky, thus enabUng the operator with two horses to cultivate both sides of a row at one time. The corn cultivator is still built essentially on this principle with 200 cohn chops many types of shovels and improvements for ease in con- trolling as illustrated in Figs. 63-66. Modern cultivators may be fitted with four to eight shovels, the size of the shovels decreasing as the number in- FiG. 67. — Two-row corn cultivator for three horses. creases. The six or eight shovel type is usually preferred where the ground is in good tilth and the weeds small. Where the ground is hard and the weeds large, so that the land must be plowed rather than cultivated, the large four shoveled type is more effective. On stony land the spring tooth gang is often preferred. Also most standard riding cultivators may be fitted with disk gangs. Disk cultivators do excellent work in the hands of a skilled operator. They are especially desirable when 201 202 CORN CROPS the soil is in poor physical condition and needs pulver- izing. Two-rowed cultivators adapted for use with either two or three horses are now in general use. If two-row cul- tivators are to be used, the rows should be straight and uniformly equal distances apart. With the two-row cultivator it is not possible to do as careful work close to . J \) .- iiiiiiit"ai ^^^K k '|SiCliflBBH^'^''^--HV^^TBi^'^^'^^ ^^^m m I^M ^^^^ m Fig. 69. — Late cultivation of corn, with narrow tooth plow. the row as when a single row is worked at a time. On the other hand, when the corn is clean in the row it may do all that is necessary in half the time. One horse cultivators are not used m^ach in corn cultiva- tion, except occasionally for late cultivation where the plants are too high to straddle. For listed corn a variety of tools has been specially devised. A spike tooth harrow is often used to level the ridges shghtly when the corn first comes up. Then a tool- such as illustrated in Fig. 70 is sometimes used or, more commonly, a two-row tool of the type illustrated in Fig 71. The first time over, the disk followers are usually THE PRINCIPLES OF INTERCULTVRE 203 set to throw out, as shown on the right of the figure, with a shield to protect the young corn and a pair of small Fig. 70. — Tool for cultivating listed corn the first time over. shovels to work in the bottom of the furrow. Later the disks may be set wider apart and set to throw toward Fig. 71. — Two-row listed corn cultivator. the com. The shovels may be adjusted to suit con- ditions. 204 THE PBINCIPLES OF INTERCULTVRE 205 140. Jethro TuU said, "Tillage is manure," and this axiom has been more cr less accepted and inculcated into our theories regarding the interculture of hoed crops. In the case of small grain crops, which are sown thickly- enough to fully occupy the land, benefit has rarely been derived from interculture. With crops which are planted wide apart and which never fully occupy the intervening ground, it has been found profitable to give sufl^cient interculture to prevent the growth of weeds. How much more interculture may benefit the crop than by keeping down weeds is a debated question. Various reasons have been advanced to account for the benefits of intercxilture and these may be summarized as follows : To destroy weeds. To conserve moisture. To reduce run-off of rainfall by keeping the surface loose and porous. To aerate the soil. To increase availability of plant food. The relative importance of each of the above functions of interculture will vary according to locality and season. Interculture to aerate the soil and to free fertility may be important on certain heavy clay soils in a humid region, but negligible on more porous soils or in & dry region. Where torrential rains occur during the growing season, it is important to have the surface in a porous, granular condition. In general, however, the conservation of moisture and the destruction of weeds are properly advanced as the. principal objects of interculture. Of all objects, the de- struction of weeds appears to be paramount. This con- clusion is arrived at as the result of numerous experiments, which have shown that keeping down weeds by shaving 206 COBN CROPS off has given almost as good results as when the soil was given good cultivation. METHODS OF TILLAGE COMPAEED 141. In the following tables are shown the results of three of the above-mentioned experiments under very different climatic and soil conditions, namely, New Hamp- shire, Illinois, and Utah. All give the same general con- clusion — that culture beyond the destruction of weeds has not given much increased yield. TABLE XLVIII Results at Three Stations with Different Methods of Cultivating Corn. New Hampshire Station (Bul. 71, 1900) Kind of Cultdbe Yield BusHELn PER Acre No culture, weeds permitted to grow . . Shallow, 14 times Shallow, 5 times (ordinary culture) . . 17.1 80.6 79.1 69.7 Mulch, covered with swamp hay . . . 56.1 Illinois Station (Bul.' 31, 1894) Average Yield for Kind of CnLTURB Five Years Bushels per Acre None, weeds scraped with a hoe . . . 68.3 Shallow, about four cultivations . . 70.3 Deep, about four cultivations .... 66.7 Shallow, about eight cultivations . . 72.8 Deep, about eight cultivations . . . 64.5 None, weeds allowed to grow . . THE PRINCIPLES OF INTERCULTURE 207 Utah Station (Bul. 66) Kind of Cultithe Average Yield fob Eight Ybass Bushels per Acre None, weeds pulled by liand Scuffle hoe (scarified) Shallow tillage, IJ inch Medium tillage, 2J inches Deep tillage, Sj inches Mulched with soil 51.8 58.8 52.9 57.3 57.4 55.8 It has been shown by numerous experiments on bare soils that a mulch of straw or of dry loose earth would conserve considerable moisture. It has also been pointed Out heretofore (page 87) that the need of water is the most common limiting factor in corn production. Rea- soning from this, it seems that interculture should play an important part in conserving moisture and this increas- ing yield, but practical experiments fail to show such increases. WATER-LOSS FROM FALLOW SOIL 142. For three months (April, May, and June) the prospective cornfield is essentially a bare field, exposed to wind and sunshine ; and it is to be expected that early plowing and maintenance of a soil mulch will conserve moisture during this period. At the Wisconsin station adjacent plots of land were plowed in early spring seven days apart. During this interval of seven days the unplowed plot lost 1.75 inch of water, while the plowed plot had actually gained mois- ture in the first 4 feet, probably due to capillary water from below. 208 COBN CROPS Widstoe' states that " Fortier, working under California conditions, determined that cultivation reduced the evap- oration from the soil surface over 55 per cent." At the Utah station similar experiments have shown that saving of soil moisture by cultivation was 63 per cent for a clay, 34 per cent for a coarse sand, and 13 per cent for a clay loam. EVAPORATION UNDER CORN CROP 143. When the corn becomes large enough to shade the ground, which will be soon after the time that interculture begins, most of the conditions causing loss of soil moisture in fallow soils will have become to a large degree ineffec- tive. Wind, the most potent cause of soil drying, is almost nil at the soil surface ; direct sunshine is cut off, the soil being in shade part of the time ; and humidity is higher! At the Nebraska station, jars of water set in wheat fields level with the soil surface lost practically no water. Another important factor in preventing loss of soil water by evaporation is the spread of roots near the sur- face. (See page 27.) If there is no rain, practically all water moving upward from the subsoil is intercepted by these roots and used by the plants. If there is rain, the surface moisture is soon reduced by the surface roots to a point where upward capillary movement is retarded. From the above, it appears that interculture of the corn crop can do very little toward conserving moisture. THE EFFECT OF WEEDS 144. A crop of weeds will not only take out moisture, but also consume available plant food. As plant food in ' ' WiDSTOE, John A. Dry Farming, p. 155. TBE PjRINCIPLES OF INTEBCULTUBE 209 available form is usually more limited than the water supply, the consumption of plant food by weeds may be even more injurious than the consumption of water. Only when water and fertility are far in excess of the needs of the crop could weeds do no harm. The effect of witch grass in reducing yield is illustrated by data obtained at the New Hampshire station (Bulletin 71, page 55). Two plats of corn were treated in the same manner and given good cultivation up to June 10. One plat was hand-hoed four times after this date in order to destroy the witch grass, while this was allowed to grow in the other plat. TABLE XLIX Effect of Witch Ghass in Corn Kind op Culture Hoed . Unhoed Pounds of Corn Stover 11,843 9,188 Bushels of Shelled Corn per Acre 81.6 61.4 We may conclude that, for corn, the principal object of intertillage is to destroy weeds, and after this is accom- plished, further tillage will not pay. The above does not apply to small tilled crops, as vege- tables where the soil is exposed and the roots do not fully occupy the surface soil. Here conditions approach thosie obtaining on fallow soil. DEPTH AND FREQUENCY OF CULTIVATION 145. Since intertillage in corn apparently serves no important function beyond subduing weeds, it is to be expected that no increase in yield will result from culti- 210 CORN CROPS vating more deeply or more frequently than is necessary in order to accomplish this purpose. In TableXLVIII are shown results at the New Hamp- shire, lUinois, and Utah stations with deep and shallow tillage. The Illinois * results with methods of cultivation may be summarized as follows : — TABLE L ■ Kind of Cultivation Ayebage Yield FOB Five Yeabb Bushels per Acre Frequent (4 plats) Ordinary (4 plats) Shallow (4 plats) . Deep (4 plats) 68.6 68.6 71.5 65.6 The principal injury of deep cultivation is that roots are destroyed. The depth to which the soil can be stirred without injury to roots depends on the soil to some extent. (See page 28.) In humid regions and clay soils, perhaps 2 inches is the limit ; in loose loam soils in drier regions, the roots are ordinarily 3 inches below the surface ; while with listed corn, the cultivation may often be as- deep as 4 inches. The roots are usually shallow next to the plant and deeper midway between rows. It is doubtful whether it would be an advantage to give deep culture, even when it could be done without particular harm to the roots, as illustrated with listed corn at the Kansas station. Roots of listed corn are deeper than surface planted corn, and there would be little injury from deep culti- vation. I 111. Agr. Exp. Sta., Bui. 31 : 356. THE PBINCIPLES OF INTERCULTUBE 211 TABLE LI Results at Kansas Station with Deep and Shallow Cul- ture FOR Corn. Average for Four Years (1892- 1896).! Treatment Listed, deep culture Listed, shallow culture Surface planted, deep culture .... Surface planted, shallow culture . . . Surface planted, deep and shallow culture^ Surface planted, siurface culture .... AvBEAGE Yield Bushels peh Acre 29.7 29.3 27.3 27.0 28.1 23.0 In Table XL VIII are also given results with frequency of cultivation. The following data from the Kansas sta- tion further illustrate : ^ — TABLE LII Times Cultivated Times Cultivated Two-year Average Two-year Average Yield in Bushels PEE Acre Three times a week . . . Twice a week ..... Once a week Once in two weeks . . . Once in three weeks . . . Once in foiu* weeks . . . 17 13 7 4 3 2 24.8 27.2 27.8 26.2 24.0 16.9 We may therefore conclude, from the data presented, that up to the time when corn shades the ground, and the "Kansas Bui. ^^.-233. ' Deep first cultivation and shallow later. 8 Kans. Agr. Exp. Sta., Bui. 45 : 131. 212 CORN CROPS field is comparatively fallow, cultivation conserves some moisture as in any fallow soil. After the corn crop is thoroughly estabhshed and a layer of surface roots inter- cepts capillary moisture from below, the principal service of cultivation is to destroy weeds. Weeds compete with the plant for both water and plant food. GROWING COBN FOR SILAGE 146. The general discussion has thus far had in view the culture of corn for grain. The recommendations taken as a whole apply quite as well to growing silage corn. It is generally true that the best quality of silage is made from corn grown under conditions for producing the maximum grain crop. For grain it is necessary that the variety chosen should mature sound grain, but in the case of silage corn it need not mature. In the Southern States, and in practically all the Corn Belt States, perhaps the best silage variety is also the best standard variety grown for grain. In New England and on higher elevations in all Northeastern States, the most profitable silage variety will probably be too late to mature. At elevations of 1000 feet or more, seed may be secured at the same latitude but grown 500 to 1000 feet lower elevation. The growing season of corn usually shortens about one day to each 100 feet increase of elevation. At lower elevations it will be neces- sary to go 200 to 300 miles south for late seed. Dent corns are usually preferred for silage, Learning being perhaps the most popular dent variety for this purpose. At higher elevations very early dents, sweet corns, and in some cases flint corns, are best. As pointed out heretofore (page 179), the total weight of dry matter increases with rate of planting, but the propor- THE PRINCIPLES OE INTEBCVLTUBE 21S tion of ear decreases. In general, the best rate, yield and quality both considered, is about one-fourth to one- third thicker than would be necessary to secure maximum yield of grain under the same conditions. Drills are best where the corn is planted somewhat thickly, as for silage. Even where hill planting has been found best for grain growing, drill planting has usually given slightly larger yields of stover. The difference, however, is too small to be of much importance, and the method to be adopted is to be determined by convenience in tillage and harvesting. Where harvesting is by ma- chinery, drill planting is most convenient; but where harvesting is by hand, hills are preferred. CHAPTER XVIII ANIMAL AND INSECT ENEMIES The corn crop is more easily protected from its animal and insect enemies than most of the important crops. Of those insects that hve on the roots of com, practically all are effectively controlled by rotation. At present the com rootworm and root-louse do considerable damage throughout the corn-belt, wherever several corn crops are grown in succession on the same land. Rodents and birds do some damage every year, but are only considered serious, where corn is grown in small areas. The corn ear worm is difficult to control, but this in- sect seldom does serious damage except in the Southern States. BIBDS 147. Crows give some trouble in regions where they are plentiful and the acreage of corn is comparatively small. They pull up the plants for a period of two weeks after the shoots appear, in order to get the kernels for food. Scarecrows or strings stretched with pieces of paper at- tached are effective in small fields. Coating the seed with coal tar is a deterrent, but not a complete preventive. The treatment consists in dipping a paddle in hot coal tar and stirring in the seed corn until every seed is coated with tar. The seed is allowed to dry and is then planted. RODENTS 148. Small' ground squirrels of several varieties dig up seed one to two weeks after planting. The coal-tar treatment 214 ANIMAL AND INSECT ENEMIES 215 recommended for crows is ofteii effective as a preventive. Poison is also used. The ordinary method of poisoning, is to soak a quantity of corn in a strychnine solution and plant this a few days ahead of the regular planting, in parts of the field likely to be molested. Very often the squirrels come mostly from adjacent pastures or meadows, and a few rows of poisoned corn planted next to these will be effective. INSECTS 149. The larvse of several insects are very injurious to corn under certain conditions. These may be grouped as : (1) Insects injurious to the roots. (2) Insects injurious to the young plant above ground. (3) Insects injurious to some part of the mature plant, as ear or leaf. (4) Insects that become abundant in cornfields only when corn follows corn year after year, as the corn rootworm. The remedy for this kind is rotation of corn with other crops. (5) There is another group, which injures corn only when it follows certain other crops. This includes the wireworm, which is often injurious the first and second years after grass sod. The grubworm is most often inju- rious after a clover sod. (6) Certain migratory insects, as the chinch bug, army worm, and stalk borer, which come in mostly from adjacent fields. The most important of these insects from an economic standpoint are here given, together with suggestions for their control : — • Cutworms Cutworms live on various kinds of grasses. The moths lay their eggs in late summer. These eggs soon hatch and the partially grown larvse live over winter in the ground. They live on vegetation again the following year 216 COBN CROPS and pupate during May and June. The larvae feed prin- cipally during the night, cutting the young plants off near the ground. Late fall plowing usually destroys many of the larvae. Late planting will often avoid them, and when the regular planting is destroyed it is usually safe to depend on a late replanting to escape. Cutworms are poisoned by mixing one pound of paris green to forty pounds of bran. When applied with a drill the mass is moistened and dried, so as to cause the poison to adhere. When applied by hand, a quart of molasses is added to the mixture. Grubworms These are larvae of the May beetles, or June bugs. The eggs are laid in June, mostly in grasslands, but more or less in all cultivated fields, especially if recently dressed with barnyard manure. The larvae live on decaying vegetable matter or roots, and often prove very destruc- tive in cornfields. No effective remedy has been proposed except in regions where listing is practiced. Listed corn is not injured so much as is surface-planted corn. Wireworms These are the larvae of the family known as " click beetles." The eggs are laid in the spring, in soil on grass- land. The larvae usually live two years in the soil; then pupate in July and August, and are finally transformed into beetles in about four weeks. The larvae both eat and bore the stems and roots of plants. No success- ful remedy has been proposed. When damage is expectedj the corn may be planted more thickly, depending on thin- ning where the wireworms do not reduce the stand. When ANIMAL AND INSECT ENEMIES 217 replanting a field injured by wireworms the new rows are planted midway between the old, leaving the old plants as food for the worms. Note. The above pests, cutworms, grubs, and wireworms, give most trouble on grass sod. They seldom give trouble after cultivated ciops where clean culture has been practiced. There are two insects that are most troublesome where continuous corn culture is practiced — the corn rootworm and the root-louse. Corn rootworm There are two species, known as the Western and the Southern corn rootworm. The larvse are similar and work in the same way, though the beetles differ in color. In early fall the female beetles lay about a dozen eggs in the ground near the corn roots. These remain over winter and hatch the next spring. The larvas are about the size of a pin and two-fifths inch in length, almost colorless except for the head, which is .yellow. They do most harm in July and August. Starting near the tip of a large root they bore inside the root, toward the plant. As they multiply rather slowly and as corn is their only host plant, the rootworms are serious only where the land has been in continuous corn culture for three or more years in succession. Corn root-louse Injury from the corn root-louse is very irregular, due no doubt to its natural enemies which ordinarily keep it in check. When unrestrained, however, it increases so rapidly that it may become very injurious in a short time. Usually its injury occurs in spots rather than over the whole field, due probably to local centers of infection from which it spreads rapidly. During the summer the 218 COBN CBOPS wingless females produce living young continuously, which in turn at the end of a few days also begin producing young. The lice live on the juices that they suck from the corn roots. Winged females occur occasionally, which estab- lish new colonies. In the fall both winged taales and females appear. This last brood lays eggs which live over winter. Ants are often associated with plant Uce and it is thought that they assist in protecting them and in caring for the eggs. No practical way of restraining the lice has been sug- gested, except that early plowing and clean, thorough preparation of the land will destroy to a large degree those present in the soil. The corn ear worm The ear worm is the larva of a moth. Two to seven broods are produced each year, depending on latitude, about four broods being the average at the 40th parallel., It is the brood produced at silking time that is most injurious. The worms eat off the grains near the tip of the ear, not only destroying directly considerable grain, but also opening a way for fungous diseases and ear rot. Migratory insects Chinch bugs. — While chinch bugs breed in cornfields, the principal damage is due to migrating bugs from adja- cent grainfields after harvest. The migration of wing- less bugs is prevented by barriers, such as a dust mulch 10 feet wide, harrowed every day to keep loose, or a plow furrow with post holes every 2 rods where the bugs collect and may be destroyed by kerosene. A barrier of tar is sometimes used. ANIMAL AND INSECT ENEMIES 219 Fig. 73. — ■ Ear of corn showing corn smut. 220 COItN CROPS Army worms. — Where army worms migrate, the remedy generally recommended is to establish a post- hole barrier by plowing several furrows toward the colony ; in the bottom of the last furrow, dig post holes into which the army worms fall and are killed with kerosene. DISEASES OF CORN 150. The diseases affecting corn are the common corn smut ( Ustilago zea}, and certain ear rots, the most serious of which is caused by a fungus known botanically as Diplodia zeat. Other forms of ear rot are caused by species of Fusarium. Both these diseases live over on infected stalks and ears, producing spores abundantly the follow- ing spring and summer to infect the new crop. The only remedy is to gather up and destroy by fire the infected material. Corn is remarkably free from injurious diseases. It is rarely that the loss from smut or ear rot in a field will amount to so much as 1 per cent. Occasionally serious loss occurs. References on insects injurious to corn : — 111. Agr. Exp. Sta., Bui. 44. Insect Injuries to the Seed and Root of Indian Corn. 1896. 111. Agr. Exp. Sta., Bui. 79. The Corn Bill-bugs in Illinois. 1902. lU. Agr. Exp. Sta., Bnl. 95. The More Important Insect Injuries to Indian Corn. 1904. lU. Agr. Exp. Sta., Bui. 104. Field Experiments and Ob- servation on Insects Injurious to Indian Corn. 1905. 111. Agr. Exp. Sta., Bui. 130. Experiments with Repellents against the Corn Root-aphis. 1905 and 1906. 111. Agr. Exp. Sta., Bui. 131. Habits and Behavior of the Cornfield Ant. 1908. U. S. Dept. Agr., Farmers' Bui. 259. Corn BiU-bugs and Root Louse. ANIMAL AND INSECT ENEMIES 221 N. C. Agr. Exp. Sta., Bui. 203. Com Weevils and Other Grain Insects. Ky. Agr. Exp. Sta., Bui. 145. Corn Pests. Ala. Agr. Exp. Sta., Circ. 8. Budworms in Corn. U. S. Dept. Agr., Bur. Ent. Bui. 85. The Corn Root Aphis and Seed Corn Ground Weevil. References of corn diseases : — Kans. Agr. Exp. Sta., Bui. 23. Corn Smut. Nebr. Agr. Exp. Sta., Bui. 11. Smut of Indian Corn. U. S. Dept. Agr., Farmers' Bui. 69. Corn Smut. U. S. Dept. Agr., Farmers' Bui. 234. Dry Rot of Corn. 111. Agr. Exp. Sta., Bui. 133. Bar rots of Corn. CHAPTER XIX HARVESTING THE CORN CROP 151. In the New England States, where corn culture first developed, it was the custom from the beginning to harvest the stalk as well as the ears. " Topping " was a common practice, the stalk above the ear being cut off for forage when immature, and later, when the ears had matured, these being " snapped " off and stored in barns to be " husked." With the opening up of the North Central and Western States, from 1840 to the present time, corn became an important article of commerce. The acreage of corn increased rapidly and, with little use for the stover, the custom of harvesting only the ears became general. In the Southern States, the corn area has never been extensive and a part of the forage has generally been saved. The custom of " topping " and " stripping " has been more general in the Gulf States than in other regions. Corn has also been found to be the cheapest and best crop for silage ; in dairy regions throughout the North- eastern States, corn is grown principally for silage, the entire crop of large dairy regions being utilized in this way. In the Central and Western States, only a small propor- tion of the stalks are harvested for either silage or stover, but the practice of harvesting the entire plant is increas- ing. It is customary, when only the ears are harvested, 222 BABVESTING THE CORN CROP 223 224 GOUN CROPS to turn the farm live stock into the fields during the winter months to eat what they will of the leaves, husks, and smaller parts of the stalk. TIME OF HARVESTING 152. The object should be to harvest at such a time as to secure the maximum amount of digestible food. The total dry weight continues to increase up to the time of ripening, as shown by the following data : — TABLE LIII Incbbasb of Dhy Weight as kepoktbd by Three Stations Approximate Date Yield of Dky Matter pek Ache Condition when Habvested New Yorki (Geneva) Pounds Michi- gan 2 Pounds Kansas = Pounds Aver- age Pounds Percent- age of Increase Ears in silk . Ears in milk Ears in glaz- ing . . . Ears ripe Aug. 10-15 Aug. 25 Sept. 15 Sept. 25 3,000 4,300 7,200 8,000 3,670 5,320 7,110 8,020 6,868 7,716 9,548 3,335 5,496 7,342 8,523 65 33 16 > Ann. Rpt. 1889. ^ u. S. Dept. Agr., Farmers' Bui. 97: 12. s Kans. Agr. Exp. Sta., Bui. SO : 181-207. At the time when corn is in tassel or in silk, less than one-half the dry weight has been developed. Increase in dry weight continues up to maturity. There was an average increase of 16 per cent from the time corn was glazed to time of maturity. There is an increase not only in total dry weight, but in all valuable constituents, as shown by the following data from the Michigan sta- tion : — - HARVESTING THE CORN CROP 225 TABLE LIV Yield per Acre op Green Fodder, Dry Matter, and Nutrients Time of Ctjtting Green FODDEB Dkt Mat- ter Pro- tein NlTRO- QEN- FHEE Extract Fat Fiber August 10 (tasseled) August 25 (in milk) September 6 (glaz- ing) September 15 (ripe) 21,203 25,493 25,865 23,007 3,670 5,320 7,110 8,020 472.7 576.0 711.0 696.9 1,828 3,212 4,554 5,356 67.9 143.1 199.0 242.6 1,010 1,148 1,294 1,413 Not only does the total yield increase, but the quality improves with maturity. The large group of compounds under the head " nitrogen-free extract " are not all equally valuable for feeding purposes. Starch and the sugars are the most valuable and both increase in propor- tion as the plant matures, due to the development of ear, as shown by Jordan of the Maine station.'- ^ TABLE LV August 15, ears beginning to form August 28, a few roasting ears September 4, aU roasting ears September 12, some ears glazing September 21, all ears glazed Percentage op Starch and Sugar IN Nitrogen- free Extract Pounds of Starch AND Sugar PRODUCED per AcRH 368.5 1,172 1,545 1,764 2,244 1 Maine Agr. Exp. Sta., Bui. 17: i. 2 U. S. Dept. Agr., Farmers' Bui. 97 : 12. 226 CORN CROPS RELATIVE PBOPOKTION OF PARTS 153. Before considering the time and method of harvesting the whole plant, it will be well to note the relative proportion and value of the different parts of the corn plant at various stages of growth. The Michigan station has studied this subject and reported the following results : ^ — ■ TABLE LVI Percentage op Total Dry Matter in Leaves, Stalks, and Ears op Corn Plants at Four Stages op Growth (Mich- igan Station, 1896) Time of Cdttinq Peecentage of Total Dry Matter Leaves Stalks Ears August 24 (in milk) .... August 31 September 7 (glazing) . . September 14 (ripe) . . . 36.41 33.63 30.03 21.77 34.27 25.52 25.53 31.91 29.32 40.85 44.44 46.32 COMPOSITION OF PARTS 154. The total dry weight alone does not give a com- parative statement of the relative feeding value of the parts of a corn plant. The leaves are very high in al- buminoids, while the stalks are low in these compounds. Pound for pound, leaves are about twice as valuable as stalks. A further study of the distribution of the princi- pal compounds of the plant at different stages of growth is reported as follows : — 1 U.' S. Dept. Agr., Farmers' Bui. 97: 9-12. HARVESTING THE CORN CROP 227 TABLE LVII Distribution op Albuminoids and Nitbogen-fbbb Extract IN Leaves, Stalks, and Bars of Corn at Dipperent Stages op Growth Albuminoids NlTBOGEN-FEEB ExTSACT Leaves Stalks Ears Leaves Stalks Ears August 24 (in milk) August 31 September 7 (glazing) . September 14 (ripe) 52.50 51.06 42.71 30.60 10.00 2.53 5.19 10.70 37.50 46.41 52.10 58.70 38.50 28.40 20.50 15.90 17.50 23.64 25.30 29.40 44.00 47.96 54.20 54.70 The above tables show very clearly the shift in relative proportion of dry weight and important food constituents from leaves and stalk to ear, as growth progresses. From the data presented in the last five tables it would seem that corn should be allowed to stand until quite mature before harvesting, since the total yield and quality apparently improve. There are two considerations against this : the loss of leaves, and the fact that both leaves and stalk become less palatable with maturity. RELATIVE VALUE OF PARTS 155. From the last two tables it appears that at the time the ear is in the " milk " stage, the relative dry matter is about equally distributed between leaves, stalks, and ears, although 40 to 50 per cent of the total nutrients are in the leaves alone. There is then a gain in ear until 46 per cent of the dry weight and about 56 per cent of the nutrients are found in the ear. 228 COBN CB0P8 RELATIVE FOOD VALUE OF EAES AND STOVER At the time corn would be cut for silage or fodder, when the ears are glazed, about 40 per cent of the protein and 20 per cent of the nitrogen-free extract are in the leaves ; or, of the total food value of the plant at this time, approxi- mately 30 per cent is in the leaves, 15 per cent in the stalk, and 55 per cent in the ear. Armsby ' compiled the data from four stations and cal- culated the yield of ears and stover to be as follows : — TABLE LVIII Station New Jersey (deat) . Connecticut (flint) . Wisconsin (dent) Pennsylvania (dent) Average . . . Eabs 4,774 4,216 4,941 3,727 4,415 Stoveb 4,041 4,360 4,490 2,460 3,838 The above average shows that about 53 per cent of the crop by weight is ears ; but the ears contain a higher percentage of digestible nutrients than does the stover, and a calculation of the digestible nutrients in the above shows about 63 per cent in the ear and 37 per cent in the stover. The above figures represent the distribution of nutrients at the time the stover is cut for forage, but do not indicate the final distribution of digestible nutrients. Fodder is usually cut when the ears are glazed in order to save the valuable leaves, and about ten days before it is ripe. But during this period there is considerable trans- location of sugars and starch from the leaves and stem to 1 Penn. Agr. Exp. Sta., Rpt. 1887. HARVESTING THE COBN CBOP 229 the ear, so that in the fully matured corn crop, under normal conditions, between 60 and 70 per cent of the digestible nutrients will be in the ears. This ratio would not apply to corn planted thick for silage, when the proportion of stover is increased without decreasing the yield of ears. There is also considerable increase in total weight between the time the ears are glazed and the time when they are ripe, usually amounting to about 10 per cent. The value of stover obtained must be decreased by what- ever loss is occasioned by early harvesting. Charging this loss against the stover, it would appear that the total feeding value of the crop is increased about 25 per cent by harvesting the stover when the ears are glazed, in com- parison with allowing the crop to mature and harvesting only the ears. In conclusion, corn should be permitted to become as nearly mature before harvesting as is practicable. As pointed out heretofore (page 227), two-thirds of the value of the stover is in the leaves, and it is therefore important to save these. In a humid climate, with fall rains, it is often possible to allow corn to stand until most of the ears are mature before cutting ; but in a region with dry falls and windy weather the harvesting must be done seven to ten days earlier, if the leaves are to be saved. TIME OF HARVESTING FOB SILAGE 156. When the silo first came into use, the custom was to use very immature material. It was found in time that silage from mature corn was better in quahty and the yield was greater. There is a limit, however, in this direction. Silage, in order to keep well, must pack closely, 230 conn crops and as nearly as possible, all air must be excluded. Corn too mature cannot be packed closely enough, though sprinkling with water and careful tramping will allow the ensilaging of corn even when more than half the ears might be con- sidered ripe. As a general rule, when the husks have mostly turned yellow, and two to four bottom leaves have turned, is the Fig. J5. — A modern silage ,. cutter, with blower at- Proper time. tachment, for delivering Good silage Contains about 75 the cut silage. ^^^ ^^^^ ^^^^^^ ^^^ j^ j^ doubtful whether it would be practicable to ensile corn containing less than 65 per cent moisture. METHODS OF HARVESTING 157. The four methods of harvesting maize are as fol- lows : — 1. Stripping: leaves removed while green for forage, and ears husked later. 2. Topping : tops cut off above ear for forage, and ears husked later. 3. Ears only harvested, stalks left in field. 4. Entire plant harvested for silage or fodder. Harvesting by hand 158. Stripping and topping are practiced in the belief that in this way the forage may be obtained while green and in the right condition to harvest, while the ears are allowed to remain and mature. It has been EABVESTING TEE CORN CROP 231 232 CORN CROPS shown/ however, that both stripping and topping reduce the yield of grain, so that it is doubtful whether the total yield of grain secured is greater than when the whole plant is harvested as fodder. The loss of shelled corn has generally amounted to 10 to 20 per cent, which is about the usual loss when harvested as fodder. The Texas station reports the labor expense of topping and stripping to be as follows : — Tops only: Cost per ton of dry-cured fodder .... |2.13 Leaves only: Cost per ton of dry-cured fodder . . . . 7.67 As it takes about four acres to produce a ton of leaves and half as much for a ton of tops, the value of the forage secured does not compensate for the loss of grain and cost of harvesting. 159. Hand cutters. — Probably the first tool used in harvesting fodder was the hoe. Corn knives came into use in time, those made from old scjrthe blades being the most common at first. Corn " hooks " were also made by inserting a short blade at about right angles in a short wooden handle. There are severd,l standard types of knives and hooks on the market. Horse-drawn cutters 160. The first horse-drawn cutters to have a general use were sleds, drawn astride of the corn row, with a heavy knife attached in front at the right height to cut off the corn plants, or drawn between two corn* rows with a heavy knife attached to one or both sides for cutting 1 Miss. Agr. Exp. Sta., Bui. 33: 63. 1895. Penn. Agr. Sta., Rpt. 1891 : 58-60. Ga. Agr. Exp. Sta., 23 : 81-82. 1893. Ark. Agr. Exp. Sta., Bui. ^4: 120. J6- JJ J4 c7cT 28 27 <58 c57 d " Fl^ u. L____^ S-^^SMB^ .y ■■'■■■■ : :,_::3a 1 '^' F^ UiW. ■' ^P"- '■' ■ ■■ -'*!t;i ; t^^ ^^ > i ■ '^S i. ri4 k '= l^p L ' jf ^ *; ' ' ■ '' ■^r ^J^nt"^/- H^^ U -^.■:::;^?^?3^ ^*»SiHa-../:;^^-' I "- ~^-'^^?3£^iL™-„i~i^5^ Fig. 86. — Large cement grain tanks, such as are used for storage at terminal markets. (Erie Railway, Chicago, 111.) in certain sections of the East and South, the use of fer- tihzers on corn is becoming more common. The rent of land is fairly well standardized, being in general about $5 per acre for land capable of producing 40 to 50 bushels per acre. The amount of labor varies with soil. The required labor to produce an acre of corn on the heavy clay lands of the East is probably twice that required on the prairie land of Iowa and would be still 248 CORN CROPS less in central Nebraska and Kansas, where listing is a general practice. The cost of growing and harvesting ears from standing stalks has been reported from many sources, the general results being illustrated by the following data : — ■ TABLE LXII Cost of Hak- Date of In- vestigation Cost pek Ache of Raising VESTING Ears FROM Stand- ing Stalks Yield per Acre Total Cost Cost PER Bush- el Dollars Dol- lars Bush- els Dol- lars Cents American Agri- culturist sum- marized from several states in the corn belti. . . . 1897 8.43 1.00 39.2 9.43 24.0 Minnesota^ . 1902-04 8.25* 3.51 40* 11.76 29.4 7.35 2.60 40* 9.95 24.9 Nebraska '" . . 1909-10 10.06 1.59 39.3 11.62 29.6 1 Book of Corn, p. 3 Nebr. Bui. 122, p. 2 Bureau of Statistics, Bui. No. 48, p. 41. * Estimated. Earlier estimates when both land and labor were cheaper indicate that corn was produced for 20 cents per bushel in the period from 1885 to 1895. The fertility of land is an important factor in the cost per bushel or ton, as the ex- pense of raising is little if any more on good land than poor. The cost of harvesting fodder corn and silage has been estimated in another place (page 241). CHAPTER XX USES OF CORN 179. Perhaps nine-tenths of the corn crop is fed to live stock. The remainder is used in the arts, in manufac- turing glucose, starch, corn meal, breakfast foods, hominy, corn oil, and alcohol, etc. The husks are used in mat- ting, the stalks and pith in packing, and corn cobs are used in making tobacco pipes. Corn meal and hominy have been important articles of food among American people from Colonial days. The use of corn as food has declined since the Civil War, probably due to the large production of wheat at low cost. The principal corn-meal market at present is in the Southern States, where it is extensively used by the people of both races. There is a general but light demand for " fancy corn-meal " throughout the country. The two principal grades of meal are whole meal and " degerminated " meal. In the first case, the whole corn is ground and only the coarsest bran removed, giving a yield of about 94 pounds of meal from 100 pounds of corn. This meal contains all the germ which darkens the color and adds its own flavor. Within recent years, degerminat- ing has become general in making fancy meal. The germ and bran are all removed, the meal well ground and bolted, giving about 40 pounds of meal to 100 pounds of corn. This meal is often called " granulated " meal. 249 250 CORN CBOPS Corn bran and germ meal are the by-products of meal manufacture, both of which are used for stock- food, while the germ meal is also used in the manufacture of prepared breakfast foods. Hominy is whole or cracked corn with the hull removed. Originally hominy was prepared by soaking the whole corn in a strong lye solution, which caused the hulls to loosen and was then removed by washing, but at present, the hulling of commercial hominy is done with machinery. Grits is coarse ground hominy, but the commercial product is usually prepared as an intermediate product in the grinding of meal. Germ meal is a by-product in the manufacture of corn- meal and starch and is composed principally of germs. Glucose or corn sirup is made by inverting the starch of corn by means of dilute hydrochloric acid. The germ is first removed and put on the market as germ meal or pressed to extract the oil. Gluten feed is the resi- due after glucose is extracted and is very rich in protein compounds and has a standard market value as stock food. Corn oil is extracted by pressure from the separated germs, which are about 30 per cent oil. The oil is used as a salad oil, in paints, or vulcanized as a substitute for vulcanized rubber. The residue after extracting oil is known as corn oil cake. ' Starch. — Corn was an important source of starch at one time, but potatoes are more commonly used at present. The starch is extracted by washing from the corn flour. A residue is left known as gluten feed. Distillery products are the residue left as a result of distilling alcoholic beverages. The starch is largely removed in distilling, leaving a iermented by-product, ■USHS OF COEUr 251 high in protein content, which is put upon the market in various forms as stock food. Pop-corn products. — A large proportion of the pop-corn crop is utiUzed with no other preparation than popping, with a small amount of butter and salt added for seasoning. The popped corn is also used in various confections and in prepared breakfast foods. Sweet com products. — The sweet corn crop is utilized as green corn on the cob, as " canned " corn, and " dried " corn. Dried corn was at one time an important home- made article of food and considerable was sold as a com- mercial product. Canning is the principal method of preserving green corn and has become an important commercial industry. Cereal food products. — Corn, either as grits, germs, or popped, is utilized to some extent in various prepared cereal foods. A common method is to. cook the cracked hominy until soft, then roll into thin flakes, which are then dried. The cooking and drying increases the soluble sugars, and more or less carmelizes the carbohydrates. Com meal is utilized in various ways. Corn-meal mush and samp is made by simply boiling in water with a little salt, and is well known. Polenta, made in the same way, is said to be almost a national dish in Italy. The three principal forms of bread made from corn meal are hoe-cake, johnny-cake, and brown bread ; the formulas for which are given on the following page.^ In the " Cotton Belt " of the United States corn furnishes the principal bread food, rather than wheat. In other sec- tions of the United States — also in Europe — corn meal is used in proportions varying from 5 to 50 per cent in a variety of bread and pastry foods, where a coarse flour is desirable. 1 Maine Bui. 131, p. 139. 252 CORN CROPS JOHNNT- CAKB Gbams Bbown Brsad Gbams Hoe-cake Gbams Corn meal . . ... Flour (wheat) Salt Sugar Bating powder Molasses Water Milk 100.0 100.0 5.0 10.0 4.4 150.0 100.0 100.0 4.0 4.4 40.0 200.0 100.0 "5.6 5.0 400.6 References on corn as food • — Food Value of Corn and Corn Products. Farmers' Bui. 298. 1907. Indian Corn as Food for Man. Maine Bui. 131. 1906. CHAPTER XXI ^ SHOW CORN The culture and characteristics of show corn deserve special discussion. , 180. Corn shows, in common with poultry and live stock shows, serve a practical purpose, in so far as they sustain Fia. 87. — Show ears of Boone County White. A typical white variety of the corn-belt. interest, and serve as a rallying ground for those interested in production. On the other hand, show corn is not necessarily the best type to grow or most productive, and farmers have often 253 254 COBN CROPS ii»^a!^«3 S"5 gg^-l?*i e^^^SKtr:;^^ made the mistake of buying it to plant under conditions not suited to that type of com. Usually show com is grown imder the most favorable con- ditions of climate and soil. There are certain regions, such as seuthem Indiana, central Illinois, and Missouri River bottom land, where com appar- ently attains a perfection ia type not possible under aver- age conditions. Our study of acclimatiza- tion developed the importance of growing seed com under conditions similar in soil and climate to the region where it is to be used as seed. This makes it doubtful whether com grown under the most favorable environment is best adapted for average conditions. The future of com shows does not rest so much on practical considerations as aesthetic . A sound, perfect ear of com is beautiful, artis- tic, and pleasing to the senses. The plant on which it grew is interesting in the same way; Fig. 88. — A typical ear of show corn, Ried's yellow dent. SHOW CORN 255 The ear also represents the largest and most interesting crop in the United States, and the principal means of sup- port of many millions. So long as men admire perfect ears of com, the com show will last. 181. Show corn is judged, on the basis of degree of perfection exhibited, both in soimdness and general sym- metry, imiformity, and beauty. It must be perfectly sound and matured, and free from signs of deterioration due to disease or improper care. The characters of show corn may be grouped in two classes, as those that pertain to soimdness and maturity and those that pertain to perfection in symmetry and uni- formity. The first class is of practical value and applies in the judging of all seed corn. The second class of points cannot be said to be important to consider in seed selection. 182. Maturity is judged by the general plumpness and development of the kernels. If the kernels are loose on the cob, or unduly shrunken at tip or crown, the ear probably did not mature properly. 183. Soundness is judged principally by the vitality of germs and strength of germination. Good germs should be plimip, of a texture similar to good cheese, and no signs of discoloring. Any variation from this can usually be seen, but it is not always possible to judge the viability by examination alone. A germination test is sometimes necessary to determine this point. Fancy characters pertain to the perfection and symmetry of development of all parts of the ear, as butts, tips, rows, kernels, etc. 184. Standards of perfection have been adopted in re- gard to a few of the best-known varieties, but at present these standards are not regarded very much by corn judges, but rather a imiversal standard has come to be 256 CORN CB0P8 recognized, which is applied to all exhibits, more or less regardless of variety. For dent corn the following standards are generally- accepted : Shape of ear. — Cylindrical or nearly so. The circum- ference should be about three-fourths the length. Size of ear. — The standard size of large dent varieties is ten inches in length and seven and one-half inches in Fig. 89. — Ideal butt and tip ends of dent corn. Note the regular size of kernels in both cases. circumference; of medium dents, eight inches long and six inches circumference. Rows. — The rows should be straight, and each row be full length of ear and extend well over butt and tip. Short or irregular rows are regarded as imperfections. Butt ends. — The butt end should be well rounded, not flat. The shank should be about one-half the diam- eter of cob. If smaller, the ear is liable to fall off the stalk ; and if larger, the ear is more difficult to husk. Tip of ears. — The rows should extend in a regular way well over the tip. Only a small exposure of cob at SHOW CORN 267 the tip end is allowed. Full depth of grain should extend almost to the very tip of the ear. Type of kernel. — A good kernel of large dent com should be about seven-eighths inch in length and three-eighths in width, if an eighteen-row ear, but narrower if more rows. The kernels should fit close from tip to crown, being somewhat keystone shaped. The kernels should be fairly thick, averaging in the row about six kernels to the inch. The kernel tip should be full and square ; the germ, large, plimap, and of good Fig. 90. — Cross-seotion of very fnlnr nnH tpvtiirp deep-kerneled type of dent corn COlOr ana texture. commonly known as hackberry. GROWING SHOW CORN 185. The seed must come from a good show strain with many generations of selection for type. The soil should be naturally good com soil, and everything done to put the soil in perfect condition, by proper rotation, manuring, and tillage. The soil, however, can be too rich in nitrogen for best results, as the plant is then inclined to run too much to stalk rather than ear. The soil should be rich in available minerals. Good show ears seldom come from the portion of field where the growth is rankest, but rather from a part where growth of stalk is normal but ears large. The rate of planting should be rather thin, about two- thirds normal stand. 258- COBN^ CROPS The crop should be handled so as to insure a rapid normal growth throughout the season without a check. Fig. 91. — An example of prolific com. CHAPTER XXII SWEET CORN OR SUGAR CORN By Albert E. Wilkinson Sweet corn is grown chiefly as a vegetable for table use, although the stover is usually harvested as forage for stock. Sometimes sweet corn is planted as a silage or forage crop. The development of sweet corn has been dis- cussed in another place (page 79). VARIETIES AND TYPES 186. Sweet corn may be divided into about the same general classes and types as field corn. The height of the stalk varies from three to ten feet and the number of rows on the ear from eight to twenty. Practically all common • colors are found. The time from planting to maturity varies from 65 to 110 days. 187. As mentioned before (page 23) sweet corn is any one of the starch corns (flint, dent, or flour corn) that has lost its faculty of coverting sugars into starches; hence, a large part of its carbohydrate material remains in the form of sugar, although some starch may be developed. Sweet com culture is most extensive in the vicinity of large cities, where it is grown as a market-garden and truck crop, and in regions where it is grown as a can- ning crop. 188. According to the latest census, 1910, the number of farms reported as growing sweet com in the United 259 260 CORN CROPS States was 48,514, the number of acres, 178,224, the value of the product, $5,936,419. New York leads with the number of farms reporting, having 6,584, the number of acres being 23,739, and the value of the prod- uct $942,023. Penn- sylvania is second in number of farms, 4,896 reporting sweet corn. The second place in number of acres, however, is with Il- linois, 19,976 acres. Illinois is also sec- ond in the value of the product, having $558,746. Ohio is third in the number of farms, having 4,591. Maryland is third in the num- ber of acres, report- ing 18,387 acres de- voted to the crop. In total value, An ear of green corn, at proper stage New Jersey takes for table use. ^^^^^ pj^^.^^ ^^^ $557,708. Around the large »cities of the northern part of the United States, large areas are devoted to the Fig. 92.- SWEET CORN OR SUGAR CORN 261 262 CORN CROPS production of sweet corn for immediate consumption. Farther back and in several of the states, in particular Illinois, Indiana, Iowa, Maine, Maryland, New York, and Ohio, the great canning industry is developed, and large acreage is devoted to the growing of sweet corn for canning. VARIETIES The varieties can be classified under three heads: (1) canning, (2) commercial or market garden varieties, and (3) home garden varieties. The principal canning variety is a late eqm, Stowell Evergreen. Country Gentleman is also used to a large extent among the caimers. In the Maine canneries, a com known as Clark's is used. This is a com which has been developed by the large canning houses, and the seed is grown in that section. Farther west, the Hickox is used to a considerable extent, while Trucker's Fa- vorite and Evergreen are considered desirable in some sections. 189. The commercial varieties may be subdivided into three or four divisions. Among the early varieties are Cory, Adams Early, Early Maine, Peep o' Day, Aristo- crat ; medium earlies. Metropolitan, Golden Bantam, and other golden corns, Honey, Quincy Market, and Crosby; late varieties. Country Gentleman, Stowell Evergreen, Late Mammoth Hickox, Black Mexican. In the home garden varieties, quality is of first impor- tance. The custom is either to plant early and late corn, or one high-class variety such as Golden Bantam every two weeks for both early and late. A not unusual sequence of varieties is : Cory, Crosby, Quincy Market, Country Gentleman, and Stowell Evergreen. SWEET CORN OR SUGAR CORN 263 SEED 190. The canning men as a rule raise their own seed, or have it raised on private farms by contract. In raising seed it is important to keep it free from contamination with other varieties, especially with field corn. When a sweet com field is within a quarter of a mile of field com, the sweet corn ear is likely to have kernels that resemble the field corn, due to wind-blown pollen. All blocks of seed corn should be far enough apart to protect against cross- pollination. The commercial grower or market-gardener very often produces his own seed. In some cases the seed has been maintained on the same farm for many years. Some of these growers have suc- ceeded by careful selection in developing desirable early types suited to their needs and as a result are able to market their product very early and secure the highest price. 191. The home gardener must depend practically from season to season upon the product that he can buy of the seedsman. If the seedsman is one who practices good methods of breeding and selecting his com, the re- sultant seed is high class. If the seed is grown under con- tract and care is given, the results are satisfactory. When a large firm is responsible, it is reasonable to expect that the corn will come true to name. 192. Breeding and selecting sweet corn offers an interest- ing field for investigation. As explained before (page 105)' the sweet com grain type and starchy grain do not blend in hybridizing. The sweet com type of grain is a reces- sive. This makes it possible to cross sweet corn with any type of starchy corn and, by selecting sweet corn grains from the hybrids, have pure sweet corns at once which 264 CORN CROPS may be combined with many or all the characters of the starchy parent. SELECTING AND CUEING SWEET CORN 193. Methods of selecting seed sweet com vary with different growers. One way that has been found satis- factory is herewith given. For many years it has been the custom to select for home planting a number of ears having characteristics ::: VK1 ■ ■ "k ~i v ;t')ci;; 1 i i: " i Ii:; :::::£!ii liillHi ■■II :: 1 fit i :? : 'A IP s! ■■1 is" :: :: ::: 1 ■■■■■ ■■■*^ : i'.KS 1 :;:;; y:t::; :: ■■ : ^, ■1 k' ;s: !■■■ ;: ;;; :: : : ::•■: :::: !! 1 : ::;y:;::::: : 1 r^. ; ::: :: : ■ an ;: :i :: !i s»3:"i*.i :::::::: ■ ■ ■■■ kvBB P . K :!SS4 ■■ T g EI^.;j:rs ■■■ :: ■ •j: : :: ;::: : jii::: ::» : 1 is : :: :::: s 1 Ii : i: Siii s Ii i ■■ 1 ■■ 1 j ■ ■ i illll 1 ■■■■■ ■ inii 1 III iS! !:! ill !!::■■■■ :ii:s:ii ■ i ! j ■■1 ■■! ;s! ■Si ■■ ! ii : ■i 1 ■Si« i:ssisss:::i:i:iisis!:::!:ij .;:i :■■:;;•■■• is:s::iiKCi:i::ssii::::sissiSi::isss:i i:i:::;::::::::r^i:::::i !ii:i::::!::i;KSiSiiSi:i Fig. 94. — Handy rack for drying seed corn. most desirable'. Earliness is maintained only by saving the earliest ears from the early corn, and from these eariiest ears a small number, known as "double extra," are set aside for the breeding-plat. In selecting these double extra ears, it is important to note, not only size, length of grain, and length of cob, but also the character of the SWEET CORN OB SUGAR CORN 265 com for quality, as denoted by its translucent appearance. It is important to practice rigid selection, that is, not only to have a great many of the right kind of ears, but to plant none or the wrong kind in the breeding plat or near it. One of the most important factors in the sweet com industry is the proper curing of the seed ears. Sweet corn molds and ferments more easily than field com. This greatly injures germination. Freezing before curing also injures germination. 194. Drying seed corn by fire heat is often practiced in seed houses equipped for the work, but is not the most prac- ticable method on a small scale. Corn thrown in a large pile with or without the husk on will develop heat enough inside of twenty-four hours to injure the germ, sour the cob, and discolor the grain. Sweet corn cut and shocked up like field com will sour before it dries, imless the weather be both cool and dry enough before winter to escape in- jury by freezing. Com left on the stalk untouched until the husk opens will be greatly discolored and injured by a spell of hot, damp weather. If, however, the ears be husked out on a dry day and allowed to lie a few hours exposed to the direct rays of the sun, the organisms which cause fermentation are killed by the simshine, and a layer of impervious matter is formed over the butt end of the cob, which makes it more difficult for fermentation to start. The following method of curing sweet com seed is recommended : When the husk is dead and loose on the ear, wait for a bright, clear day, begin early in the morning, and cut down a small piece of corn, throwing into piles. The same forenoon, when the sun is shining bright, husk it out as rapidly as possible, throw the corn into small piles on the ground, tie the fodder into bundles, 266 COBN CROPS and set it up in small shocks. Before night, haul in the com and put it on a slatted floor. The floor is made of lath one inch thick by two inches wide, spaced one inch apart. The corn is taken up in baskets, and each basket is turned upside down on the slats, and taken off carefully, so that the ears are left like a pile of " jack-straws," crossed in every direction, many of them standing in a nearly verti- cal position. Each basketful of com is emptied in a fresh place, and when all is done the slats are covered with com about a foot deep, but so loosely arranged that there is no obstruction to the passage of air between the ears. In this position it dries very quickly and may be put uito barrels as soon as all moisture is Out of the cob. Each barrel may be covered with a piece of cloth held down by the top hoop, and then the barrel turned on its side. This plan applies more to the regions with hiunid fall weather than to those regions in the West where fall weather is dry. GROWING SWEET CORN FOB CANNING 195. Canning corn is grown under contract with the firm in many corn-growing regions. The caimiag company sends out a contract similar to the following : — Sweet corn agreement (Place), (Date) This agreement made with the Canning Com- pany, by which I hereby agree to plant and raise for said Company acres of sweet com, the same to be de- livered at factory from time to time as required by said Company, in proper condition for canning during the season of 191-; for which said Company agrees to pay seven dollars per ton, said Company to furnish me at their factory seed com at the proper time for planting. For SWEET CORN OB SUGAR CORN 267 said seed com I agree to pay said Company two dollars per bushel on or before the first day of October, 191-, or from the proceeds of com delivered on this contract. I further agree (1st) to plant said com in three different plantings, first planting, acres, to be planted early in May ; second and third plantings, acres, to be planted the last of May or the first week in June, or after each preceding planting is well up. (2d) Not to let any corn become heated or damaged by remaining in bulk too long, and to deliver said corn the day it is picked. (3d) To make a short snap close to the ear. (4th) It is further agreed that the corn covered in this contract shall not be paid for till October first, 191-. (5th) That corn must not be planted near field corn unless it be white field corn, as mixed yellow corn is unfit for canning. In case of destruction of the cannery by the elements, said Company not to be held liable for damages on this contract. (Signed) (The Company) (Signed) (The Farmer) 196. Rotation. — It is often to the advantage of the growers to plant their cannery corn crop in rotation with other crops. It is desirable that the com can be planted following a sod, especially if on this sod from eight to ten tons of stable manure are applied and plowed under. From experiments, sweet corn is found to be greatly benefited by deep plowing in some soils. If choice of soil is obtain- able, the piece of ground that will give the most satisfac- tory results is a gravelly or a sandy loam, especially if there is some chance of having humus, such as sod or manure. The corn is generally planted with a machine, either one- or two-row corn planter ; and at the same time, some growers apply from three to five hundred pounds of 268 COMN CROPS a 3-8-5 fertilizer formula, or if the manure is deficient, up to 1000 to 1200 pounds of fertilizer of the same formula. In some cases, growers raising sweet com place not only the above amount of manure on their ground, but some- times more, and add the larger amount of fertilizer, as well. 197. Distance between the rows in planting is from 30 to 42 inches. Sometimes the distance between the hills in the rows is but 24 inches, and other times it will extend to 36 inches. The general custom is, with the smaller-growing varieties, to lessen the distance, whereas with the large-growing varieties, such as Stowell, the dis- tance is increased so that each plant may have a normal amount of space for full development. More seed is gen- erally planted in the hill than is required, from five to eight seeds being dropped in each. Later, this corn is thinned to three or four stalks to the hill. By this pro- cess the three or four best developed plants are allowed to remain. The weeder is used soon after the seed is planted, or a fine-tooth harrow. When the corn has broken ground, the weeding is generally discontinued, and a fine-tooth cultivator used. This may be a one-row or a two-row cultivator. The general plan at first in cultivation is to till rather deeply, especially in the middle of the row between the plants, later tilling more shallow. The corn plant requires constant tillage and a good soil mulch for its best development and conservation of the moisture. Hand hoeing would be necessary if weeds were troublesome, especially if the plot was not check-rowed. However, there are some men that go to the extra care of check-rowing their corn, and cultivating in two direc- tions, then omitting the hand hoeing. It may be an ad- SWEET CORN OR SUGAR CORN 269 vantage to go through with a hand hoe, because, at the same time that hoeing is performed, sucker growths may be removed from the corn, thereby improving the quality ■and size of the ears. When it is seen that the horse and machine in cultivating are injnring the corn, this work is discontinued, and the corn is allowed to grow without farther attention. About the time of marketing, the factories generally send a man to the field to instruct the farmer just when to bring the corn to the factory. In the different sections, there is some difference of opinion as to when the corn should be harvested for the factory and just how. In general, the corn should be delivered to the factory as soon as possible after breaking from the stalk. There are some companies that desire the corn broken in the morning and carted immediately to their factories. As stated in a number of reports received from canners, they did not desire the growers to pick the corn in the late afternoon and allow this to stand in the wagons over night, owing to heating of the corn. In harvesting, the ear is broken from the plant so that there is very little or no stub left on the base, and the unnecessary husks as well are taken off. However, no extra attention or care is given at this period. The corn may be gathered in baskets or in boxes, and immediately emptied in a wagon. When the wagon is full, it is taken to the factory and there weighed, if sold at so much a ton green weight. 198. Thirty-five dollars is a fair return for an acre, ex- clusive of the value of the fodder, as well as the husk and the cob, which the growers can take back to their farms. The average returns for sweet com to the acre are between three and four tons. Example : On good Iowa land, a 270 COBN CBOPS farmer will average with a good stand about three tons per acre. Some years the yield will be as high as four and one-half tons. The price varies, but for large Evergreen com from six to seven dollars is received per gross ton of corn with the husks on, and for smaller varieties the price is from $7.50 to $8.50 per gross ton. Other states report different yields and different prices for their com. Very much depends on the cannery, the methods em- ployed, and several other factors. The above are average figures. Besides the com grown for the canneries under con- tract, canneries often grow a large acreage of corn for their own use. The work there is conducted similarly to that of the men who contract with them. They plant their com at different periods, so that it may extend over a long season and they may, by so planting, be able to keep the factory busy throughout the season. MARKET SWEET CORN Commercial com growing for consumption in the green stage may be classed as : market-garden sweet corn grow- ing, which embraces the extremely early and a small amount of the main season crop ; and truck growing sweet corn, which never embraces the extremely early crop, but only the main and late crops. 199. The market-garden crop is generally grown on high-priced land near the centers of population. The soil is generally in the best condition and of the typical market-garden type, a sandy loam well supplied with humus, and improved each year by applications of ma- nure, sometimes as high as 40 tons to the acre. Besides the heavy applications of manure, some market-gardeners use large quantities of commercial fertilizer. The general SWEET CORN OR SUGAR CORN 271 idea among them is that in order to get an early crop of sweet corn, which is the one that brings the highest money, they should have food for the plant quickly available. 200. From six to eight kernels, in some cases more, are planted ia each hill. For the early varieties, the hills may be as close as one foot. From fifteen to eighteen inches is more nearly the average distance between hills in the row. The distance between rows varies from twenty-four to thirty inches. The cleanest culture is given, and irriga- tion is practiced in some cases. Market-gardeners, by their intensive methods of plant- ing, are able to place corn on the market from ten days to two weeks earlier than men living a little farther back from the centers of population, and practicing less inten- sive methods. In cultivating the com, especially with the hoe, suckering is generally practiced. Cultivation is continued thoroughly and as along as possible, the horse being muzzled when it is found that injury results. If the corn is not growing to suit, slight applications of fertilizer, especially nitrate of soda 100 to 150 poimds per acre, are made. In planting the early and main season and late varie- ties, some planters practice sowing the seed at the same time, and allowing the difference in the period of maturity to bring the crop in at the proper time. Other growers prefer to plant their corn at intervals of ten days to two weeks. This latter seems to be the most practicable method. 201. Marketing. — As soon as the ear is at the right stage for harvesting it is broken from the plant and placed in baskets or boxes, immediately taken to the shed, and there repacked. In the eastern markets, especially in New England, the com is packed in boxes, a certain definite 272 CORN CROPS number of ears in each box. For New York and Phila- delphia and through the North and West, ears are sold by the hundred in sacks or hampers. This is' less satis- factory. It is not a pleasing pack or one that attracts attention. The bushel box is more practical, more up to date and the corn carries better. In the sack the com has been known to heat because too much was placed together. 202. The first corn coming to the market sells for thirty to forty and in some cases fifty cents a dozen. It then steadily declines until it reaches eight and even six cents a dozen. If a man has a retail route and has corn through- out the season, he usually maintains a high average price. ■ Some men never sell for less than fifteen cents throughout the season from their retail wagons. 203. The bulk of the main crop and the late crop are grown a httle farther back from cities on less expensive land, and under less intensive methods. The rows and hills are generally a little farther apart, three feet to forty- two inches between rows, and from thirty to thirty-six inches between hills in the row. Fertilizer up to a thou- sand or twelve hundred pounds is applied with the corn. The corn is commonly planted on sod groimd, this being usually spring plowed. Clean culture is practiced in the early part of the season. The corn is generally harvested the same as for the market-gardening. When grading and packing is necessary, the ears should be of uniform size and about the same degree of maturity. Better prices can be thus secured. The corn is usually shipped to commission houses, to wholesale stores, to clubs and hotels. Gross returns of $100 an acre will make a crop of com profitable. As high as $350 the acre has been received from sweet corn. SWEET COMN OR SUGAR CORN 273 FORCING SWEET CORN 204. Forcing under glass has been practiced for com- mercial corn growing. Experiments have been tried, es- pecially in New England. The Early Minnesota, Crosby, Early Cory, Adams and other varieties have been used for forcing with more or less success. A summary of sugges- tions is given here. 205. The requirements for forcing com under glass are practically the same as those for forcing other warm- weather plants, such as tomatoes, melons, cucumbers, and egg-plants, — a day temperature of 70° to 80° and a night temperature of 60° to 70° being required, the atmosphere in the house to be rather moist during the first period of the corn's growth, but when pollen begins to fall, the at- mosphere being dry. The crop should be marketed before July first, in order to be remunerative. Extra early varieties maturing in from 65 to 83 days from seed are to be used. The corn may be started in pots, either paper or clay, a few seed in each pot, and later transplanted where it is to stand in the greenhouse. Inter-cropping with radishes, lettuce, or spinach may be practiced, to utiUze all space in the greenhouse to the best advan- tage. The distance between rows should be 18 inches, and between hills in the row 9 inches. Suckers are very common in a crop of this kind, and these should be re- moved. The principal pests in the greenhouse are rats and mice. They bother both by digging out the seed and by attacking the matured ear, spoiling it for sale. Poisoning or destroying these pests should be performed before the crop is planted. 206. Forcing corn in hot beds or cold frames very early in the season, allowing it to mature in these beds, is a 274 CORN CROPS practical method. In this way, corn may be obtained for consumption in the month of June when the price is very high. The general conditions of growth are the same as those for greenhouse work. The spacing between the corn is the same. Careful attention as to ventilation and watering should be given. The pollination in the hotbed or cold frame will be looked after by the natural elements, but in the greenhouse it is advisable to shake the corn plant shghtly when the pollen is ripe. A still later method of forcing has been practiced on a limited acreage near some cities, and that is starting the__ corn in paper pots or other receptacles. Two or three seeds are planted in each pot, allowing the corn to grow from four -to six inches, and then transplanting the corn to the garden after the weather conditions have settled. The corn at this time should be four to six inches high. The roots have not suffered by being pruned, and the plant will continue its growth. This method has been tried both in the East and the Middle West, and where the demand warrants, has proved satisfactory. SWEET CORN IN THE HOME GARDEN 207. In the home garden the aim should be to have a Uberal and constant supply of sweet corn. The variety should correspond with the personal taste of the individual gardener or consumer. It is doubtful whether the extra early corns will answer the demands of the individual home gardeners, as they lack somewhat in quality. The home gardener does not have a great choice of soil for the growing of sweet corn. The garden may be heavy clay or light loam. In either case the principal treatment should be hberal applications of stable manure. Some per- sons apply a little commercial fertilizer, but this is the ex- SWEJET CORN OB SUGAR CORN 275 ception rather than the rule. No fertiUzer is needed if the garden has plenty of manure. Sweet corn in the home garden may be grown under the methods described for commercial growing. Transplanting corn from hotbeds is a feasible method for the home garden, especially for early corn. Inter-cropping of the corn, in the earliest stages when planted from seed, would be practical. Such crops as radishes, spinach, lettuce, and even beans can be grown in the home garden, utilizing apparently waste space, which later is necessary for the full development of the corn. PART II SORGHUMS CHAPTER XXIII THE SORGHUM PLANT Sorghum {Andropogon Sorghum var. vulgaris, Hackel, A. Sorghum, Brot., Sorghum vulgare, Pers.) is generally- conceded to have been originally derived from the well- known wild species, Andropogon halepensis, Brot. The wild species is found abundantly in all tropical and subtropical parts of the Old World and has been in- troduced into the Western Hemisphere, where it is now well distributed in both North and South America between the parallels of latitude thirty degrees north and south of the equator. 209. Andropogon halepensis is generally known in the United States as Johnson-grass. JohnscJn-grass is a coarse- growing perennial, with strong underground rootstocks by means of which it spreads rapidly and is very persistent, being regarded generally as a bad weed. Sorghum differs from the wild form in that it is larger- growing, that it produces more seed, that certain forms have abundant sweet juice, and that no form is perennial or has persistent rootstocks. However, there are forms of Andropogon halepensis that are annual and without the persistent rootstocks, an example being the variety known as " Soudan grass." The wild form is somewhat vari- able, having certain types paralleling in their variations the cultivated forms. 279 280 COBN CB0P8 GEOGRAPHICAL ORIGIN 210. Hackel ^ states that the cultivated forms had their origin in Africa, but Ball^ believes that they also had an independent origin in India as well. The early history of sorghum culture is unknown, but ^^0^""'^^ H^ 0^-- /^ ^ ^ll^mfp \ii ' ^t^^tJ^ ^^M kliat'^W^idr ^ k |Mw^ H w ;.OECi ^ P f J ^^ife '.. - -■ , - '-^.::ji.' .- ■ ,_■/ Fig. 95. — Plant of sorghvim. (After Fuchs, 1542.) ' Hackel, Edward. The True Grasses, p. 59. 2BALI/, Caelbton R. TJ. S. Dept. Agr., Bur. Plant Indus., Bui. 175, pp. 9-10. THE SORGHUM PLANT 281 there is good evidence that it was an important crop in both Africa and South Asia hundreds of years before the Christian Era. A reference to millet in the Bible (600 B.e.) probably refers to sorghum. (Ezek. x. 4. The word millet is translated " dochan " in the original Hebrew text, a word still in use in Arabic for various forms of sorghum.) Sorghum is well adapted to meet the needs of a primitive agriculture. The seeds provide human food, while the plant furnishes abundant fodder for animals. Under favorable conditions the plant will nin wild to some extent, and is better able to care for itself than any other of our important cultivated plants. Sorghum is at present the most important cereal food of the native people of Africa, and is a very important crop through the southern half of Asia. There are no statistics of the world's production of sorghum. The United States crop is estimated at about 3,000,000 acres and that of India at 25,000,000. The crop of Africa and of Asia Minor should approximate that of India. BOTANICAL CLASSIFICATION Order — Gramineoe. Tribe — Andropogonem. Genus — Andropogon. Species — A . Sorghum var. vulgare. 211. Ball 1 has suggested the following classification as a key to the principal groups of sorghum : — I. Pith juicy. A. Juice abundant and very sweet. 1. Internodes elongated ; sheaths scarcely overlapping ; leaves 12-15 (except in Amber varieties) ; spike- lets eUiptic-oval to obovate, 2.5-3.5 mm. wide ; seeds reddish brown. I. Sorgo 1 Ball, Cahlbton R. U. S. Dept. Agr. , Bur. Plant Indus., Bui. 175, p. 8. 282 CORN CROPS B. Juice scanty, slightly sweet to subacid. 1. Internodes short; sheaths strongly overlapping; leaves 12-15 ; peduncles erect ; panicles cyhn- drieal; spikelets obovate, 3-4 mm. wide; lemmas awnless. II. Kafir. 2. Internodes medium; sheaths scarcely overlapping; leaves 8-11 ; peduncles mostly inohned, often recurved ; panicles ovate ; spikelets broadly obovate, 4.5-6 mm. wide ; lemmas awned. VII. Mile. II. Pith dry. A. Panicle lax, 2.5-7 dm. long; peduncles erect; spikelets elUptic-oval or obovate, 2.5-3.5 mm. wide; lemmas awned. 1. Panicle 4-7 dm. long ; rachis less than one-flfth as long as the panicle. a. Panicle umbelliform, the branches greatly elon- gated, the tips drooping ; seeds reddish, in- cluded. III. Broom-corn. 2. Panicle 2.5^ dm. long ; rachis more than two- thirds as long as the panicle. a. Panicle conical, the branches strongly drooping; glumes at maturity spreading and involute ; seeds white, brown, or somewhat buff. IV. Shallu. b. Panicle oval or obovate, the branches spreading; glumes at maturity appressed', not involute; seeds white, brown, or reddish. V. Kowhang. B. Panicle compact, 1-2.5 dm. long ; peduncles erect or recurved ; rhaehis more than two-thirds as long as the panicle. 1. Spikelets elliptic-oval or obovate, 2.5-3.5 mm. wide; lemmas awned. V. Kowhang. 2. Spikelets broadly obovate, 4.5-6 mm. wide. o. Glumes gray or greenish, not wrinkled; densely pubescent ; lemmas awned or awnless ; seeds strongly flattened. VI. Durra. b. Glumes deep brown or black, transversely wrinkled ; thinly pubescent ; lemmas awned ; seeds slightly flattened. VII. Milo. THE SOBGHUM PLANT 283 212. Technical description. — The plant varies in height from about 4 feet (dwarf Milo) to 12 or 15 feet high in some of the tropical forms. Panicle, or " head," varies in shape from the small, compact " sumac " type, in which the rachis is almost as long as the panicle, through the looser and more branch- ing forms of the CoUier type, in which the rachis is about one-half that of the panicle, to the broom-corn type, in which the rachis is only one-fifth the length of the branches. Seeds. — The shape of seed varies, from round in the Kafir, Kowliang, and Shallu, to somewhat pear-shaped in certain of the sweet sorghums, somewhat flattened in Milo, and decidedly flat in the Durras. The seed coat of all dark-colored varieties has a decidedly astringent taste, due to the presence of tannin. The amount of tannin seems to vary with the color, being greatest in the black- seeded and dark red varieties, very little in yellow seeds, and there being none in white seeds. The astringency apparently has no ill effect except as it affects flavor, the dark-seeded grain not being so desirable for stock food on this account. Stems. — ■ Stems vary not only in height (from 4 to 15 feet), but also in relative thickness. The Amber variety is slender, with stems less than 1 inch in diameter, while in the Gooseneck variety the stems are 1 to 2 inches thick. In slender-stemmed varieties the nodes are usually long, about 12 inches; while in the stouter-stemmed varieties the tendency is toward short nodes, as in the Sumac, the average length being 8 or 9 inches. Juices. — Stems are designated as juicy or dry. The actual water content of the green stems does not differ so much in the two cases, the green stems being 80 to 90 per cent water. In the juicy-stemmed varieties the juice is 284 COBN CB0P8 easily extracted by crushing and pressing. An ordinary roller cane press will extract 50 to 60 per cent of the juice. Not all juicy sorghums are sweet, but practically all the very juicy varieties are. The sugar content of the juice in sweet sorghums varies from 10 to 18 per cent. Leaves. — The leaves of the sorghums are strong and are especially well adapted to withstand the rather dry and often hot winds that prevail in semiarid regions. In periods of protracted drought the leaves assume a rather erect position, rolling together to a considerable degree in a way that appears to protect against exces- sive evaporation. All the very drought-resistant forms, as the Milo and Durra types, are rather scanty-leaved; the leaves being about eight to ten in number, rather broad and short, and rather coarse in texttire. Tillers. — All varieties of sorghum seem to produce tillers abundantly. These appear at the lower joints of the stem. The buds that develop into tillers may re- main more or less dormant when conditions for growth are unfavorable, ready, however, to develop at the first favor- able opportunity. Fertile soil and thin planting favor their development. Certain varieties, however,' seem to produce two or more tillers normally, the tillers starting almost as soon as the main stem, and it is only under the very thickest planting that they are suppressed. It sometimes occurs, when the first part of the season is dry and unfavorable, that the main stem may become stunted ; if late rains come, the tillers will often grow much taller than the main stalk. The tillers are later in matur- ing and are considered undesirable when the crop is grown for grain or sirup ; but" they are usually desirable when the crop is grown for forage, as they no doubt in- crease the yield of fodder. TBE SOBGHUM PLANT 285 When sorghum plants are cut off, tillers usually spring up at once. In the South two crops, and even three crops, may be cut from the same roots. In regions of very mild winters the roots of certain varieties will live over, giving a crop the second year. Branches. — Branches come from latent buds on the upper part of the stem as tillers do from the lower nodes. The same conditions that > favor tillering favor the development of branches. The first branch appears from the topmost node, the second from the next, and so- on down, in order; under very favorable conditions and thin planting, four or five branches may develop. Each branch bears a small head, similar to the main head but later in maturing. Branches are considered undesirable, and the usual plan is to plant the sorghum thick enough so that there will be neither tillering nor branching. Roots. — The Kansas station made a study of Kafir corn and sweet sorghum roots in comparison with corn and other field crops. The roots of Kafir corn were found to be finer and more fibrous than corn roots under the same con- ditions. A few. of the longer Kafir roots penetrated to a depth of 3 feet, but most of them were confined to the upper 18 inches, filling the soil to this depth with a fine network of roots; while corn under the same conditions fully occupied the upper 30 inches with roots (see Fig. 12, page 27), sending its deepest roots about 4 feet. The sweet sorghum roots were somewhat intermediate in char- acter, but resembled the Kafir more than the corn roots.^ The distribution of roots indicates that the sorghums draw their nutrients from the surface soil much more than com. 1 Kans. Agr. Exp. Sta., Bui. 127, pp. 207-208. 1904. 286 CORN CROPS PHYSIOLOGY OF THE SOKGHUMS 213. In general, the physiology and nutrition of sor- ghum are similar to those of corn, which has been set forth (page 38). The most interesting physical phenomenon of sorghum from an economic standpoint is its general re- sistance to drought and to the climatic conditions that prevail in dry climates. Drought resistance. — The drought resistance of sor- ghum is well established. Its ability to yield in a dry chmate is apparently not due to a deep root system or to any other adaptation of the root system so far reported. Neither does it seem to be due to a low water requirement, as the few tests made on this point indicate that quite as much is required per pound of dry weight as for Indian corn or for other crops not particularly adapted to dry conditions. The success of sorghum, under semiarid conditions seems to depend on two qualities, not found developed to so great a degree in other crops : (1) The high resist- ance of leaves to injury from hot, dry weather. The non- saccharine groups, especially, will withstand dry and hot climatic conditions that would wither most vegetation be- yond recovery. (2) The plants have the faculty of becom- ing almost dormant, so far as growth is concerned, for long periods during severe drought. During such periods the leaves roll and tend to assume an upright position. This, no doubt, reduces evaporation from the leaves and affords protection to the younger leaves and the seed head. The plant may remain in this condition, apparently without growth, for several weeks, far beyond the endur- ance of most cultivated plants. With the coming of rain, growth will usually be renewed with vigor. If the main THE SORGHUM PLANT 287 stalk has been much stunted, tillers will often grow up at once and become taller than the main stalk. While tillers do not usually produce a good seed crop, they are satisfactory as forage. REPHODUCTION 214. The sorghums are all " perfect-flowered " — the pollen and ovary being in the same flower, instead of in separate flowers as in corn. This is the principal botanical distinction between the tribe Maydew, to which corn belongs, and the tribe Andropogonece, to which sorghum belongs. FERTILIZATION 215. All sorghums are adapted to both self-fertilization and wind fertilization. Apparently, self-fertilization is normal in the sorghums, and is in no way injurious as it is in corn (page 107). In developing pure strains of sorghum it has been found practicable to cover the heads with bags before blooming, thus securing complete self-fertili- zation. NATURAL CROSSING 216. Under normal field conditions more or less crossing takes place. Regarding this point BalP makes the fol- lowing statement : " Just to what extent cross-fertihza- tion takes place under normal field conditions, it is, of course, impossible to say. However, in the case of ad- jacent rows of different varieties, flowering on approxi- mately the same dates, as high as 50 per cent of the seed produced on the leeward row has been found to be cross- fertilized. It is probable that in a fairly uniform field of any given variety a similar percentage of natural ' Ball, Cableton R. American Breeders' Association, Vol. VI, p. 193. 288 COBN CROPS crossing takes place. Many writers have stated that such cross-pollination occurs also at very long distances, but this seems to be less conclusively proved. Probably a distance of 8 to 10 rods to leeward is the maximum at which appreciable hybridization occurs." Ball also states that the pollen is mostly shed during the early morning hours, when the winds are usually at lower velocities than later in the day. Crossing of types. — ■ All the different tj^jes of sorghum, as sweet sorghums, non-saccharine types, and broom-corns, cross readily. (See Fig. 115.) Broom-corn growers must exercise some care in keeping their seed stocks pure, in regions where other varieties of sorghum are grown. CLIMATE AND SOILS 217. The entire botanical genus (Andropogon) , made up of hundreds of species, is found growing principally in wide-open plains regions. Hackel ^ states, " the species prefer dry places, especially savannas." Climatic requirements Temperature and sunshine. — Sorghum, like corn, is a plant of tropical origin, varieties of which have been adapted to temperate climates. Like corn, it requires abundant sunshine and warm weather, being very sensitive to cool nights. At high elevations where nights are gen- erally cool, sorghum seldom does well even when the days are warm and sunshiny. Humidity and rainfall. — While both corn and sorghum require sunshine and warmth, they apparently differ somewhat as to humidity, corn preferring regions of high ' Hackel, Edwakd. The True Grasses, p. 57. THE SOBQHUM PLANT 289 humidity such as prevail in the Mississippi valley, and sorghum preferring regions of dry air such as prevail in the Great Plains region of the upper Missouri River valley and southward. The above general difference may be due in part to selection of varieties. Sorghum being of tropical origin and widely distributed, certain varieties flourish in very humid regions of Africa. Certain varieties of the sweet sorghums grow well in the Carolinas and Gulf States, where both rainfall and humidity are high. While certain sorghums do well under humid conditions, the ability of all sorghums to remain more or less dormant during periods of drought, and to renew growth with the return of rain, has qualified the crop for adaptation to dry climates. For centuries sorghums have been grown and adapted to dry conditions in the Old World as they are being further adapted in the United States. The result is that the principal varieties of sorghum under cultivation prefer a drier and warmer climate than is required by the corn crop, although no doubt varieties of sorghum could be foimd equally adapted to humid regions. The above conclusion applies with more truth to the grain sorghums (Kafirs and Dvu-ras) than to the sweet sorghums or broom- corns. Soil requirements 218. The sorghums are adapted to a wide range of soils, but they prefer a medium-weight loam to very light or very heavy soils. The grain sorghums are apparently more sensitive in this respect than the sweet sorghums. Sor- ghtmis for forage are often grown on poor land, not only because they produce more forage than any other crop under such conditions, but also because the stems are finer than when grown on heavy land. V 290 COUN CHOPS 219. Effect on the land. — The sweet sorghums sown thickly have the reputation of being " hard on the land." Grain sorghums planted thin seem to have the same effect also, in lesser degree. All millets have the same reputation. No very satisfactory explanation for this has been ad- vanced. When the effect is noted it is most marked on the first crop following, and less marked afterward, usually completely disappearing in one or two years. The effect is most marked on small grain and less on intertilled crops. As the sorghum roots are rather concentrated in the upper layers of soil, it is possible that this soil is very much exhausted of available fertility. There is some reason to believe that sorghums may exhaust available fertiUty to lower limits than do other crops. It is not known whether sorghums have a toxic effect on the soil. The injurious effect when noted is considered only temporary, and farmers in general do not consider it a serious drawback to sorghum culture. 220. Alkali resistance. — ■ Sorghum is often said to be alkali-resistant. It is not resistant in the same sense as are many native alkali plants, but at least it is one of the best of our cultivated plants to succeed on land rich in alkali. SORGHUM TYPES 221. A common grouping, based principally on the economic use of the crop, is (a) Saccharine sorghums, (6) Non-saccharine sorghums, (c) Broom-corixs. A. Saccharine sorghums. Those having an abundant sweet juice. Cultivated at one time principally for sirup manu- facture, but now principally as a forage plant. Commonly known as " sorghum," I. Sorgo. THE SORGHUM PLANT 291 B. Non-saccharine sorgliums. 1. Pith contains a scant juice, which varies from slightly sweet in some varieties to subacid in others. Grown princi- pally for the grain, but also has forage value. II. Kaflr. III. Milo. 2. Pith dry. (a) Grown principally for the grain and forage. II. Kaflr. VI. Durra. IV. Shallu. V. Kowliang. (6) Grown for the bush, no value as forage. VII. Broom-corn. The economic discussion of sorghums will follow the above grouping. 292 CHAPTER XXIV THE SACCHARINE SORGHUMS Sweet Sorghums 222. This group of sorghums is usually designated as sweet sorghums, or "sugar" sorghums. They are quite distinct from the non-saccharine, grain sorghums in having a juicy stem containing a high percentage of sugar and in producing a rather light seed crop. Early culture. — The sweet sorghums have never been cultivated extensively in the Old World, where the sorghums have been cultivated more for seed than for forage — the non-saccharine forms being more productive for the former purpose. The sweet sorghums seem to have been kept in cultivation principally for the sweet canes, which, however, were not manufactured but were peeled and the juice was expressed by chewing. Almost no sweet sorghum is raised in North Africa or in India ; it has been kept in cultivation in China and South Africa, however, though only in a small way. 223. Introduction into the United States. — The first recorded introduction into the United States was from China in 1853, by way of France, and the plant was known at first as " Chinese Sorgo." This was a loose-panicled sorghum, from which have been derived most of our cultivated varieties of Amber sorghum. " Our Early Amber is said to have originated in 1859 as a sport in a field of Chinese sorgo growing in Indiana." ^ ' Ball, Cableton R. l.c., p. 25. 293 294 COBN CROPS A collection of sixteen varieties of sorghum brought from Natal, South Africa, to Europe in 1854 and from Europe to this country in 1857, included several sweet sorghums, from which have been derived 'our compact- headed types such as Orange, Sumac, and Gooseneck. Development of culture in the United States. — While sweet sorghum has remained a secondary crop in the Old World, it had a rather rapid development in the United States, owing to the belief that it would become a great sugar- and sirup-producing crop. In 1857 the United States Patent Office distributed 275 bushels in small lots to farmers ; The American Agriculturist distributed to its subscribers 1600 pounds in small packages, and the next year 34,500 pounds in the same way. At this time exten- sive experiments were being made with it in Europe for the manufacture of sugar, and later the United States Government ^ conducted an elaborate series of experiments for the same purpose. With the development of sugar beets at this time a better source of crystallized sugar was found, and the plan of using sorghum for this purpose was abandoned. First grown as a sirup crop. — However, sorghum was found to be a cheap source of home made sirup and it was more or less grown for this purpose in every rural com- munity. Local " sorghum mills " were very common dur- ing the eighties in the Central and Western States. Dur- ing the dry years in the early eighties, and again during the general drought of 1892-1894 in Nebraska, Kansas, and southward, sorghums of all kinds were found to with- stand drought. There are no available data on acreage of sweet sor- ghum, but the data on Kafir corn (page 304) indicate the 1 See U. S. Dept. Agr., Bur. Chem., Buls. 26, 40, etc. THE SACCHARINE SORGHUMS 295 $ORGi , CCMSUV1 II) THOUUNOS Fig. 97— Production of sorghum sirup middle of laat century. PROBUCTU ClNSUl IHTUOUSmOS. I/Nt7l0 iW£5 KSriTHOI/MHO eiiums Fig. 98. — Productiou of sirup at close of century. 296 CORN CROPS increase. of sweet sorghum as the acreage of the two crops of late years is about equal. Beginning with 1890, the acreage has continued to increase up to the present time. 224. How the crop is utilized. — In the Central States east of the Mississippi River, these sorghums have been cultivated principally since 1865 for the manxifacture of sirup. The extent of sirup manufacture for the census years is as follows : — Gallons 6,749,123 Year I860 1870 1880 1890 1900 16,050,089 28,444,202 424,235,219 16,972,783 The principal States in sirup manufacture for the last three decades have been Tennessee, Missouri, and Ken- tucky, but the industry has shown a rapid decrease in all these States. In only one State, North Carolina, has it shown a notable increase. Figures 97 and 98 show graphically the distribution at two periods. 225. As a forage crop. — West of the Missouri River and southward in the Great Plains region, the culture of sweet sorghum is principally as a forage crop. It is an important forage crop in the drier parts of Kansas, Oklahoma, Nebraska, and Texas. The use of sweet sorghum as a forage crop has developed since 1880. 226. Classification of sweet sorghums. — The following classification is adapted from Ball : — A. Peduncle and panicle erect. 1. Panicle loose, open, branches spreading to horizontal or drooping ; rachis two-thirds as long to equaling the panicle. THE SACCBARINE SORGHUMS 297 Empty glumes black, hairy. I. Amber. Empty glumes black, smootli. II. Minn. Amber. Empty glumes red. III. Red Amber. Empty glumes light brown. IV. Honey. Raehis less than one-half the length of the panicle : — Panicle hght, drooping branches, seeds orange to red. V. Collier. Panicle heavy, seeds orange. VI. Planter's Friend. 2. Panicle close, compact. Empty glumes equal to seeds, seed red. VII. Orange. Empty glumes half as long as the small seeds, seeds dark red. VIII. Sumac. Empty glumes narrow. IX. SapKng. B. Peduncle recurved (gooseneoked) or sometimes erect. Panicle black, glumes awned. X. Gooseneck. The three varieties that have had most extensive cul- tivation are Amber, Orange, and Sumac. 227. Amber, being the earliest of the three (90 to 100 days), has been practically the only variety grown in the northern limits of sorghum culture — that is, north of Kansas and the Ohio River — and has been most popular in Kansas, the leading sorghum-growing State. Amber grows about 5 to 7 feet tall, with 8 to 10 leaves, being neither so tall nor so leafy as the other two varieties. The seed head is usually black and is loose or spreading, though it is somewhat variable in this respect. A number of selections have been made, the best known of which are : Minnesota Amber, which differs only in minor details ; Red Amber, the heads of whidi are red instead of black but which is otherwise similar ; and Folger's Early, a strain said to be especially desirable for sirup production. The various strains of Amber sorghum have been popular for forage because of the rather slender stems and early 298 COBN CBOPS maturity, these qualities facilitating the curing and im^ proving the quality of forage. » Fig. 99. — Amber sorghum. 228. Orange sorghum is two to three weeks later in maturing (100 to 125 days) than is Amber. It is about 12 inches taller, the stalk is heavier and the nodes are shorter, THK SACCHARINE SORGHUMS 299 and the plant is more leafy. The variety name refers to the deep orange color of the ripe heads. This variety is excellent for sirup pro- duction and it makes a heavy yield of for- age, especially on good land. However, for cured forage farmers object somewhat to heavy stalks, as they are more difficult to handle and cure. Orange sorghum is second in popularity to Amber and is grown principally from Kan- sas southward. Collier and Coleman are two varieties of the Orange sorghum type which are so sim- ilar to it that for all forage purposes they may be considered the same. The CoUier is considered the better for sirup-making. 229. Sumac sor- ghum derives its name from the very com- pact red seed head, resembling the seed head of sumac. It is somewhat larger and perhaps later than Orange, but otherwise similar in Fig. 100. — Orange sorghum. 300 COBN CROPS appearance of plant. " For forty years this has been the most popular variety in the South, especially in the Pied- mont districts. It is now largely grown in Texas and Oklahoma also." 230. Gooseneck is a very large, late-growing variety, adapted only to the South. Ten to fifty per cent of the heads are re- curved, or "goosenecked." Fig. 101. — Sumac sorghum. Fig. 102. — Gooseneck sorghum. CHAPTER XXV THE NON-SACCHARINE SORGHUMS 231, The non-saccharine sorghums, with the exception of broom-corn, are often called grain sorghums because their principal value is as grain producers rather than as producers of forage. As a group, they constitute the most drought-resistant grain and forage crops in cultivation. The five principal types of the non-saccharine sorghums are: (1) Kafir, (2) Durra, (3) Shallu, (4) Kowhang, (5) Broom-corn. Historical. — The non-saccharine sorghums are very generally cultivated throughout Africa, southwest Asia, India, and Manchuria, but are not cultivated extensively in Europe. In general, the kafir types dominate in South Africa, the Durra types in North Africa, southwest Asia, and India, and the Kowhang types in Manchuria. Shallu, the least important of the five principal groups, is grown as a winter crop in India, and the same type has been reported as grown in a Umited way in Madagascar and at several points in Africa. 232. The Durra group (spelled also dura, durah, doura, dhoura, and other ways) is the most important in the Old World. It should be noted, however, that there are three general groups of the durra sorghums, only one of which is important in the United States : (1) The types grown in central and northeast Africa are tall, large-seeded, and late-maturing, furnishing both forage and grain ; (2) those 301 302 CORN CBOPS ■ 4'W 'f^W # #^ .^ c i tf « -• « • • m >' M •B V 0" M f ■MtJ a to n d o » 3 3 QS fe-3 ■ J SB ^ tS THE N0N-8ACCEABINE SORGHUMS 303 of North Africa are shorter, early, comparatively low in forage and high in grain production, and the grain is flat and of medium size ; (3) those of India have comparatively small heads and seeds, the seeds not decidedly flat ; they produce both forage and grain, but are too large and late- maturing for culture in the United States. The second group has thus far furnished most of the varieties that have found a place in United States agricul- ture. The probable reason is that grain sorghum could not compete with maize in the corn-growing belt. There was, however, a distinct demand for crops adapted to the Great Plains, a region too dry for the culture of corn. The sorghums from the more humid regions of the Old World havo not always been drought-resistant, and in most cases are too late in maturing. Most of the kafirs and durras meeting the requirements of drought resistance and a short maturing season have come from, the drier regions of North Africa and the high plains of South Africa. 233. Introduction in the United States. — The cultiva- tion of non-saccharine sorghums dates from the intro- duction of White Durra and Brown Durra into California in 1874 and the introduction of kafir in 1876, but they were not generally distributed until about ten years later. 234. Region where cultivated. — -The "grain sorghums" are cultivated for grain and for forage. They are not so desirable for forage alone as are the sweet sorghums ; the fodder is coarser and lacks the sweet sugars in the stem, being less palatable. They are commonly harvested for both grain and forage. As a grain crop they cannot com- pete with corn in the regular corn-growing belt, and there- fore the principal grain-sorghum belt lies just west of the corn-growing belt, following in general the hne of 25- inch rainfall on the east and extending west to the Rocky 304 CORN CROPS Mountains; the belt includes also southern California and Utah. The accompanjdng chart ^ (Fig. 104), prepared = /r/f£>r nwsx'S m/io /s f/OKfyi sr/iPi.E chop. — JfffEA TO IVmCIf MfLO SB A/OtV ^O^PT£D = /me/l IN WHICH THE /taifMB/UTy OFMIIO is BEIN6 TESTEO. Fig. 104. — This map made to show the distribution of milo ; also shows, approximately, the area where the culture of all sorghums are of most importance. to show the area of Milo culture, outlines the probable area of grain-sorghum culture. 235. Statistics of culture. — It is not possible to supply exact figures on the production of grain sorghums. The census of 1909 gives the total acreage of kafir grown for grain as 266,513. The principal States reported, and their acreage, were as follows : — State Acheaqb Kansas 154,706 OUahoma 63,455 Texas 22,813 California 20,218 Total .... 261,192 1 U. S. Dept. Agr., Farmers' Bui. 322, p. 11. THE NON-SACCnABINE SOBOHUMS 305 Ninety-eight per cent of the entire acreage was produced in four States. The above figures do not include that sown as forage. From the Kansas State Board of Agri- culture, however, we have data for the census year show- ing 631,040 acres sown for forage, or about four times as ? ^ m p J& ^W ^^M^ W ; "S^^M ^^^^^' aJR^ji ^^^i 1 " 1. HbK ^ Fia. 105. — Two heads of Mile, showing good and poor types. much as that harvested for grain. On the same basis for the United States it would appear the the non-saccharine- sorghum acreage for 1909 was about 1,250,000 acres. The acreage has since increased slightly in Kansas and to a marked degree in Oklahoma and Texas, so that present 306 CORN CROPS acreage is above two million acres. The value of non- saccharine sorghums is now recognized, and with the im- AcRBAGB, Value, and Yield op Kafir, Milo, and Corn fob THE Years 1904 to 1909, inclusive, in Kansas and Oklahoma KANSAS Yield PEE Valtte ACKE Crop and Year AOBEAGB IN Tons OB Bush- els Per Ton or Bushel Total Per Acre Kafir: 1904 . 518,372 3.04 $3.19 $5,041,546 $9.70 1905 . . . 538,393 3.24 3.06 5,352,810 9.91 1906 . . . 548,497 3.05 3.01 5,039,238 9.18 1907 . . . 508,485 2.94 3.78 5,658,860 11.11 1908 . . . 630,096 2.85 3.82 6,856,845 10.89 1909 . . . 636,201 2.79 2.99 4.02 7,150,080 11.21 Average . 3.48 10.33 Milo: 1904 . . . 7,166 3.18 3.22 73,476 10.24 1905 20,550 2.84 3.28 190,974 9.31 1906 . . . 17,563 2.55 3.26 146,289 8.31 1907 . . . 22,090 2.72 3.90 234,686 10.61 1908 . . . 55,255 1.92 4.85 515,269 9.31 1909 . . . 102,492 1.97 4.74 959,259 9.34 Average 2.53 3.87 9.52 Corn: 1904 . . . 6,494,158 20.3 .39 50,713,955 7.81 1905 . . . 6,799,755 28.0 .36 68,718,584 10.11 1906 . . . 6,584,535 28.4 .35 65,115,203 9.25 1907 . . . 6,809,012 21.3 .43 63,040,743 9.26 1908 . . . 7,057,535 21.3 .55 82,642,462 11.71 1909 . . . 7,711,879 19.1 .57 83,066,905 10.77 Average 23.1 .44 9.83 THE NON-SACCHABINE SORGHUMS 307 Acreage, Valtje, and Yield of Kafir, Milo, and Corn for THE Years 1904 to 1909, inclusive in Kansas, and Oklahoma oklahoma Yield PER Value Acre Chop and Ybak Acreage IN Tons or Bush- els Per Ton or Bushel Total Per Acre Kaflr: 1904 . . . 334,948 9.79 $0.40 $1,312,204 «3.92 1905 . . . 297,286 12.72 .40 1,512,318 5.08 1906 . . . 269,218 16.10 .34 1,465,937 5.44 1907 . . . 371,405 13.50 .58 2,881,032 7.77 1908 . . . 400,047 9.20 .46 2,548,200 1 6.36 1909 . . . Average 12.26 .44 5.71 Milo: 1904 1905 . . . 138,608 20.06 .40 1,112,602 8.02 1906 . . . 122,347 17.82 .40 870,767 7.12 1907 . . . 131,366 13.30 .65 1,142,098 8.64 1908 . . . 145,096 12.55 .33 757,565 2 5.22 1909 . . . Average . 15.93 .45 7.25 Corn: 1904 . . . 1,369,276 16.00 .39 8,544,339 6.24 1905 . . . 1,369,276 16.00 .39 8,544,339 6.24 1906 . . . 1,642,930 18.90 .40 12,436,657 7.66 1907 . . . 1,528,735 31.40 .36 17,142,081 11.21 1908 . . . 4,014,631 18.10 .48 35,409,961 8.82 1909 . . . 4,284,661 18.60 20.60 .48 38,449,866 8.97 Average .42 8.56 1 Includes $828,131 worth of fodder. 2 Includes $151,911 worth of fodder. 308 COBN CROPS provement of varieties they are destined to become an important crop west of the 98th meridian. The compara- tive acreage and value of non-saccharine sorghums com- pared with corn in Kansas and Oklahoma, as compiled in Bulletin 203, Bureau of Plant Industry, United States Department of Agriculture, is given above. 236. Classification of non-saccharine sorghums. — Pith juicy : (Very juicy, sweet = Sorgo.) Juice scanty, subacid or somewhat sweet or dry in certain varieties. (1) Heads erect, cylindrical, spikelets oval, small, 3-4 mm. wide, (a) Seeds white : Glumes greenish white, some darker. I. White Kafir. Glumes black or nearly. II. Blackhuh Kafir. (6) Seeds red : Glumes deep red to black. III. Red Kafir. Kafir Group DaRRA Group (2) Heads pendent but sometime secret, ovate; spikelets broadly obovate, large, 4, 5-6 mm. wide, (a) Seeds white : Glumes greenish white, silky, seeds flat- tened, awned. IV. White Durra. Glumes black, seeds smaller, less flattened, rare. V. BlackhuU Durra. (6) Seeds yellowish to reddish brown : Glumes short, wrinkled, reddish to black, not sillcy ; seeds yellowish brown ; - florets awned. VI. YeUow Milo. Glumes as long as seeds, greenish white, seeds reddish brown, not awned. VII. Brown Durra. THE NON-SACCBARINE SOBGHUMS 309 Broom- corn Type Pith dry: Head loose, 10-28 inclies long; spikelets oval or obovate, small, 2.5-3.5 mm. wide, lemmas awned : Bacliis one-fifth, as long as branches. (a) Branches drooping, seeds reddish. XI. Broom-corn. Rachis more than two- thirds as long as head : (6) Branches of panicle drooping ; glumes at maturity spreading and involute ; seeds white to buff (several varieties). VIII. ShaUu. (c) Branches spreading but not drooping, glumes at maturity appressed, not in- volute; seeds white, brown, or red. (Several varieties, corresponding to the red, white, and blaekhull varieties of Kafir and Durra. Also standard and dwarf.) IX. Kowhang. Head compact, erect or pendent, spikelets oval or obovate, small, lemmas awned : Rachis two-thirds as long as head. X. Kowhang. 237. Kafir. — • The three principal varieties of kafir are red, white, and blaekhull. The heads are erect, in con- trast to the durra group, in which the heads are mostly recurved, or " goosenecked." The white and blaekhull varieties both grow about 5 to 6 feet high, while the red is 8 to 12 inches taller. The white and red varieties were first introduced. The white variety, however, was not satisfactory because of its not maturing well, and the head was not always exerted from the leaf sheath, thus inducing rot in damp weather. The red variety matured properly and soon became more popular. The objection to Red Kafir was the astringent taste of the seed coat^ common to all kafirs with a colored seed coat. The blaekhull, a white-seeded variety, appears to 310 CORN CROPS be a later introduction, having attracted attention about 1896. It had all the good qualities of Red Kafir, and in addition the seed was not astringent. This variety probably furnishes nine- tenths of the kafir crop to-day, and Red Kafir the other tenth. 238. Durra.— The char- acteristics of this group are that the heads are mostly " goosenecked " and the seeds are large and flat. The extensive cultiu'e of non-saccharine sorghums in this country began with the introduction of Brown Durra and White Durra into California in 1874, but the culture did not become general in the Great Plains region until about 1890. The White Durra is com- monly known as " Jerusa- lem corn," and sometimes as " Egyptian rice corn." The Brown Durra is often called " Egyptian corn." White Durra is little grown, as it is frequently injured by insects and diseases. The grain also shatters badly. Brown Durra has continued in cultivation especially in southern California and Texas. The total area of White Fig. 106. — Plant of Blackhull Kafir. TB.E NON-SACCHARINE SORGHUMS 311 and Brown Durras was estimated at 50,000 to 60,000 acres in 1908.1 239. Milo, or Yellow Milo, was introduced about 1885, ten years later than the White and Brown Dur- ras, but it quickly be- came the most popular of the group, the area in 1908 being estimated at 300,000 acres. This variety will mature in 90 to 100 days and is adapted to culture as far north as south- western Nebraska. In addition to the standard varieties, there is now a dwarf variety well suited to cultivation for grain production. Compared with kafir, the durras are better adapted as grain pro- ducers but not so well suited for forage pro- duction. Milo is the best suited of all the sorghums for grain pro- duction. Early varie- ties of milo have been developed by selection, which adapts it to a Fig. 107. — White Kafir Com. 1 U. S. Dept. Agr., Bur. Plant Indus., Bui. 175, p. 34. 312 CORN CROPS Fio. 109. — Pendent form of FiQ. 108. — Upright Mllo head. MUo head. THE NON-SACCHARINE SORGHUMS 313 wide range of conditions, and this plant, together with BlackhuU Kafir, is the best of the sorghums for grain production. The milos, being about three weeks earlier in maturing than the kafirs, have two distinct advan- tages : in Oklahoma and Texas they can be planted early and will more nearly ma- ture before the severe midsummer drought ; also, they may be grown farther north and at higher alti- tudes. 240. Shallu.— This plant is of recent in- troduction. The stalks are tall and slender, with large loose and open pani- cles, approaching broom-corn in type. The plant comes from India, where it is cul- tivated as a winter crop, being sown in October and har- vested in March. It is grown for both seed and forage. Seed of this was introduced Fig. no. —Yellow MUo. 314 CORN CROPS and tested by the Louisiana Agricultural Experiment Station about twenty years ago. It is occasionally grown from Kansas to Texas. It has acquired several local names, as California wheat, Egyptian wheat, and Mexican wheat. 241. Kowliang. — In both India and China the sorghums are commonly classed with millets. " Kowliang," or " tall millet," is a Chinese name given to distinguish this variety from the common smaller millets (Panicum and Chffitochloa). The three colors of seed and glume found in kafirs and durras are found also in this group, namely, brown seeds with black glumes, white seeds with black glumes, and white seeds with white glumes. There are varieties of both dwarf and standard size, 4 to 11 feet high. Ko whang comes from northeast China and the adjacent territory of Manchuria, 38° to 42° north latitude — ■ the farthest north of any region where sorghums have been an important crop for any great length of time. They are oxtousivoly cultivated in this region for grain and forasiv and the stems are used for fuel. All varieties are earlj'-maturing, and, being already adapted to a region farther north than any other group of sorsihunis exeept the Early Amber varieties (the original Amber type also eame from China), they should be adapted to a similar latitude in the United States. They have not been extensively tried in tliis country, but the early dwarf stoeks give promise of furnishing a good foimdation stock for the development of grain sorghtmis in the northern half of the Great Plains. They could not replace Early Amber sorghvuus as a forage crop. CHAPTER XXVI CULTURAL METHODS FOR SORGHUMS 242. Sorghums are grown for four distinct purposes: (a) as a grain crop primarily, (b) as a forage crop, (c) for sirup manufacture, and (d) for broom-corn brush. The land to be chosen would be similar in each case, but the principal difference in cultural methods would come in method of sowing and harvesting. Because the sorghums will grow on poorer and drier land than any other of our cereals is to be taken as an indication not that they naturally prefer such conditions, but rather that they are capable of withstanding greater hardships than other crops. Consequently, the culture of sorghums may extend beyond the limits of common cereals; but, on the other hand, they will respond as readily to manuring and to favorable environment as will any plant, on good, rich land producing six to seven tons of cured forage per acre. Preparation. — ■ The land is prepared much as for corn. The plowing may be done in the fall or in the spring. As planting does not take place until rather late — two to four weeks after corn, — there is ample time for spring preparation of the soil. GBOWING SORGHUMS FOR GRAIN ■ 243. Varieties. — Blackhull Kafir, Milo, Red Kafir, and Brown Durra, in the order named, are the principal sor- ghums grown for grain. 315 316 CORN CROPS Fig. 111. — Heads of Sudan Durra, from San Antonio, Tex. On left, in flower latter part of May, not injured by midge. On right, in flower September 1, and almost sterile, due to midge. CULTURAL METHODS FOB SOBGHUMS 317 244. Time of Planting. — Grain sorghums are usually planted soon after corn; the time ranging from March to June in the Southern States, while as far north as Nebraska the planting must be as early as possible in order to insure maturing. Planting in Nebraska practi- cally coincides with corn planting, about May 10. In the San Antonio region of Texas it has been found necessary to plant very early in order to avoid the sorghum midge, an iasect that becomes very numerous in June and practically' prevents all seeding from that date on. In order to avoid the midge, planting must be early. According to one experiment reported in 1911, eleven va- rieties of grain sorghums planted on March 4 yielded 23.1 bushels, while early varieties planted on March 15 gave only profitable yields, and no varieties planted on April 1 were profitable.'^ 245. Rate of planting. — Grain sorghums are usually planted in rows 3 or 3| feet apart ; the plants 6 to 8 inches apart for the milos and durras, and 8 to 10 inches for kafirs. On very fertile soils the planting should be thicker than this. The amount of seed required will be 3 to 5 pounds per acre. With durras a higher percentage of the heads " gooseneck," or recurve, when planted thin than when planted thick. 246. Methods of planting. — Corn-planting machinery is generally used for sorghums, the only change necessary being to use special plates for dropping or to adapt the corn-dropping plates. The corn-planting plates can be adapted by filling the holes with lead and boring out to the right size. Grain sorghiims are always drilled. Listing is a method common in regions of low rainfall, 1 Grain Sorghum Production in the San Antonio Region of Texas. U. S. Dept. Agr., Bur. Plant Indus., Bui. 237. 1912. 318 COEN CROPS but in regions of higher rainfall and heavy soils surface planting is better. When planted in a lister furrow the seed should not be covered deeper than is necessary to Fig. 112. — Plat of Milo selected for erect heads. insure good germination, as it rots very easily when planted deep or when the soil is cold or wet. Surface planting is ordinarily done with the two-row corn-planter ; the grain drill is sometimes employed, how- ever, by using only every fourth or fifth hole. 247. Tillage. — The same tools are used in general for cultivating sorghum as for corn, and in much the same manner. However, sorghum, especially when hsted, is much slower in growth than corn for the first four weeks, CULTURAL METHODS FOR SORGHUMS 319 and consequently more skill is required to clean out the weeds. Young sorghum is tougher and less likely to break than is young corn, which is an advantage, since it permits of the use of such tools as harrows and weeders oftener and longer than is the case with corn. With surface-planted sorghums, by the proper use of harrows and weeder it is often not necessary to give more than one thorough cultivation with the shovel cultivator. With listed sorgum, the harrow and lister cultivators should be used for the first cultivation. When the plants Fig. 113. — Field of White Kafir in shock. are 8 to 10 inches high a very thorough cultivation should be made with the cultivator, to be followed later by such shallow cultivation as is necessary to keep down weeds. 248. Cutting. — ■ When grown for grain the heads should be fully ripe. If cut for silage, the seeds should be, in the soft dough stage, as the ripe seeds in silage are very likely to pass through the animal without digestion. The corn-binder is the best and most economical implement for harvesting on a large scale. With smaller areas the sled cutter is used, or the crop is cut by hand. 320 CORN CROPS Various plans for harvesting only the heads have been tried, but all these have proved less satisfactory than harvesting the whole' plant. 249. Curing. — The grain sorghum, however harvested, should be set up in shocks until well cured. Precaution should be taken to set the base of the shock wide and to tie well about the heads. The heads being heavy, the shocks are very likely to fall over. Before threshing, the sorghum heads should be very dry, as the grain heats and spoUs quickly when stored if at all damp. This will require four to six weeks in the shock. 250. Hauling and storing. — Where the fodder is fed, it is very common to haul from the field as used. Sorghum will remain in very good condition for several months when bound and set in large shocks. If not to be used for three months, it is usually better to haul and stack. Baling is sometimes practiced, a hop or broom-corn baler being used as the bundles are not broken apart. When the stover and grain are to be fed separately the bundles are sometimes beheaded with a broadax or heavy knife. The heads are then stored in a dry place, to be fed whole or to be threshed. 251. Threshing. — ■ The whole bundles are sometimes run through an ordinary grain-thresher, or only the heads run in and the bundles then withdrawn. The labor is heavy in both cases and it is often considered better to behead the bundles and thresh only the heads. Yields 252. As shown by the table on page 306, the average yield of grain sorghums in Kansas and Oklahoma is not equal to that of Indian corn ; but in these States corn is CULTURAL METHODS FOB SORGHUMS 321 raised in the part of the State having heaviest rainfall, and sorghum in the drier part. West of the 25-inch-rainfall line, grain sorghums will equal or outyield corn. The advantage increases as rain decreases. Yields of twelve to twenty bushels of grain sorghum are often harvested when corn is a failure from drought. Twenty bushels per acre is considered an aver- age crop and forty bushels per acre a good crop. Yields of seventy bushels have been known. GROWING SORGHUMS FOR FORAGE 253. Sweet sorghums are used more extensively when grown primarily for forage than are the non-saccharine. Since the foliage of all sorghums remains green until the heads are mature, a fair quality of coarse forage is secured when sorghums are grown for grain. About one- half the sorghimi crop is sown primarily for fodder, to be cut before heads are ripe and cured as fodder or hay. 254. Time of planting. — In the Gulf States sorghum is often sown early so that the crop may be cut two or three times, though sowing may continue for several months. In the Central States sowing is usually after corn planting, generally in the month of June. 255. Rate of planting. — • Sorghum for forage is either sown thick in drill rows about 3 feet apart and cultivated, or sown close, either broadcast or with the grain drill. When sown in rows to be cultivated, the methods are similar to those for growing grain except that about 15 pounds of seed per acre is used instead of 2 to 5 pounds. When sown broadcast, one to two bushels per acre of seed are used ; the thinner sowing is done on poorer land or in a dry climate, and the thicker seeding under the most favorable conditions. 322 CORN CROPS 256. Methods of planting. — Which of the two methods shall be employed — drilUng or broadcasting — depends on circumstances. In regions of low rainfall, drilling in wide rows and cultivating is the surer method, but in more humid regions there is little difference in yield. On the other hand, drilling in rows increases the cost because of the amount of cultivation necessary. The fodder is also coarser. Harvesting forage sorghum 257. When cultivated in rows the best method of harvesting is with a corn-binder. The bundles are set up in small shocks to cure. In four to six weeks several small shocks may be set together in large shocks, which '-UsJ' M r^^s",*^ m ^^ |^^1K»|^ ^M^ P ^f,- FiQ. 114. — Cutting sorghum forage with a mower. CULTURAL METHODS FOR SORGHUMS 323 are securely tied near the top and left in the field to be hauled as used. A better method is to stack in large stacks, but care must be observed that the fodder is well cured before stacking. When sown broadcast the crop is usually cut with a mower and handled as coarse hay, or cut with the grain- binder. When cut with a mower a stubble of 6 inches should be left. This tall stubble facilitates drying, and also gath- ering the heavy fodder, with a hajTake. Heavy sorghum hay dries very slowly and should be left for one to two weeks in the swath before raking and cocking. It should be thoroughly cured in the cocks before stacking. 258. An aveiage yield of cured fodder varies from 3 to 6 tons per acre. Very heavy yields of 10 tons per acre have been reported from one cutting. Where sorghum is cut two or three times a season, as in the South, the relative jdeld of the different cuttings depends on the method of handling. If the first cutting is allowed to become quite ripe, the following cutting will be light; but if the first crop is cut quite green, the second cutting may be as heavy as, or heavier than, the first. 259. Seed crop. — ■ Twenty-five to thirty bushels of seed per acre is considered an average jaeld. All sorghum sown in rows for fodder or planted thin for sirup-making produces a good crop of seed. Most of the commercial seed of sweet sorghums comes from this source. CHAPTER XXVII UTILIZING THE SORGHUM CROP 260. In Asia and Africa the grain of sorghum is utilized principally as human food, in the United States as stock food. The seed coat is hard and rather indigestible, therefore all sorghum grain fed to live stock should be ground. Composition. — The composition of kafir is shown by the following summary : ^ — Food Constituents in Kafir. In Fresh or Air-det Material Pito- NlTBO- Wateh Ash TEIN FiBEK GEN-FREE Extract Fat A UTHORITT Per Per Per Per Per Cent Cent Cent Cent Per Cent Cent Kafir (whole plant green) . 76.13 1.75 3.22 6.16 11.96 0.78 Penn. Station Kafir (whole plant green) . 76.05 1.44 2.34 8.36 11.41 0.40 N. Y. (Cornell) Station Average 76.09 1.60 2.78 7.26 11.69 0.59 Kafir fodder (whole plant . 10.94 5.48 3.31 30.37 47.40 2.50 N.C. Station Kafir fodder (without heads) . . 8.67 7.14 4.89 28.02 49.75 1.SS Kans. Station Kafir (mature head) . . . 16.23 2.02 6.92 6.79 65.18 2.86 N.C. Station Kafir aeed . . 9.31 1.53 9.92 1.35 74.92 2.97 Kana. Station Kafir flower . . 16.75 2.18 6.62 1.18 69.47 3.82 N.C. Station 1 Cycl. of Agr. IV : 387. 324 UTILIZING THE SORGHUM CBOP 325 Kafir and other sorghum seeds are considered to be very starchy foods. For good results they require that some protein food, as alfalfa hay or cottonseed meal, be fed with them. Ten per cent cottonseed meal is sufficient. Kafir grain fed alone is also constipating, and this tend- ency is corrected by the addition of a protein food fed in connection. When fed to cattle, horses, and sheep, good results are secured, though pound-for-pound feeding experiments show sorghum to be not quite so valuable as corn. In general, for fat stock, 80 to 90 pounds of corn have been found to equal 100 pounds of kafir or milo when fed in comparison. 261. Poultry food. — Sorghum seed is one of the best poultry foods and enters into a large proportion of these foods found on the market. It is considered superior to corn. For poultry the seed need not be ground but is fed whole, either threshed or in the head. 262. Soiling or green feed. — Sorghum is probably the most popular crop to cut and feed green. The sweet sorghums are used principally for this purpose. The superiority of sorghum for this use lies in its large yield, its sprouting up from the roots so that the crop may be cut several times in succession, and its drought resistance. Sorghum will remain green and growing under drier conditions than will other forage crops, furnishing succu- lent food at the time it is most needed. For green feeding it is usually drilled very thick, in rows 3 feet apart. An acre of green sorghum producing 12 tons will feed twenty head of stock for twenty days, allowing 60 pounds per head each day. 263. Pasture. — Sorghum is used considerably as a 326 . C0B2V CROPS pasture crop. For this purpose it is sown rather thick, 2 to 3 bushels per acre. Stock is turned in when the crop is 3 to 4 feet high. For pasturing, the field should be divided into lots and enough stock should be turned in to eat down the crop in about two weeks. The stock should then be removed to another lot and the pasture given four to six weeks to grow up again. This would require three to four lots. It is estimated that one acre will furnish grazing for the equivalent of one animal for one hundred days, or ten animals for ten days. 264. Sorghum mixtures for pasture. — For pasture purposes German millet is sometimes mixed with sorghum and gives good results. Cereals have been used as a mixture, but it is doubtful whether they add to the value as pasture. In the South, it has been recommended to mix sorghum and cowpeas, for both forage and pasture. Cowpeas give a better-balanced ration. For pasture the sorghum and cowpeas should be drilled in rows about 8 to 12 inches apart, in alternating rows. 265. Sorghum for silage. — Within the corn-belt, sor- ghum compares favorably with corn as a silage crop. In regions of less than 25 inches rainfall, sorghum will probably come to be the most important silage crop. In the South, also, it is likely to supersede corn for silage, especially where the crop is to be grown on rather poor land. Sorghum silage is more difficult to preserve than corn, being more likety to ferment. When well preserved it appears to have a feeding value about equal to that of corn silage, though very little experimental work on this point has been done. Sorghum for silage is now in extensive use in many places in the Southern States. UTILIZING THE SORGHUM CROP 327 266. Sorghum poisoning. — Sorghum pasture under some conditions is a virulent poison. This is due to prussic acid forming in the leaves under certain condi- tions. The conditions favoring the development of prussic acid seem to be hot, clear, and dry weather, producing a stunted growth. Poisoning is most common in semiarid regions. When conditions are right for developing poison, the sorghum should be pastured with caution, as the poison acts quickly and there is no known remedy. Cattle should not be pastured on stunted or drought-stricken sorghum. Where it is desired to test the pasture, prob- ably the best way is to allow only a single animal to graze the field for a day or two. When poisonous sorghum is cut and allowed to lie until wilted, the poisonous property entirely disappears. CHAPTER XXVIII SORGHUM FOR SIRUP-MAKING As discussed heretofore (see page 296), sorghum has had an extensive use in the United States for sirup manufacture. The process of sirup-making is so simple that nothing more is necessary than a roller press, for extracting the juice, and a single evaporating pan. In a few cases rather extensive plants have been established, but most of the sirup has been made in small local plants. 267. For sirup the sweet sorghums are used, as Amber, Orange, Sumac, and Gooseneck. There are strains of all these varieties selected for sirup-making. (See descrip- tion of these varieties, pages 297-300.) 268. For sirup the sorghum is planted and cultivated practically as described for the culture of grain sorghums. 269. Time of harvesting. — The sugar content of sor- ghum at different stages of growth as determined by Collier, the result of 2740 analyses, is given as follows : '■ — Sugar Content of Sorghum at Different Stages of Growth Stage of CtjTTiNQ Sucrose Invert Sdgab Panicles just appearing Panicles entirely out . Flowers all out . Per Cent 1.76 3.51 5.13 7.38 8.95 10.66 11.69 Per Cent 4.29 4.50 4.15 3.86 Doughy, becoming dry Dry, easily split . . Hard 3.19 2.35 1.81 ' Sorghum Sirup Manufacture. U. S. Dept. Agr., Farmers' Bui. 477:12. 328 SORGHUM FOB SIRUP-MAKING 329 270. Sorghum increases not only in total weight until mature, but also in the percentage of sugar. The seed should reach a hard dough stage before cutting. Stripping. — For best results the leaves should be stripped. This is done while the canes are standing. The canes are often pressed without removing the leaves, but if this is the case, the yield of juice is less and the im- purities are much greater. Cutting. — The canes are cut by hand or with a corn- binder. In hot weather, cutting should be done not more than two days before grinding, as there is danger of fermentation developing. In cool fall weather, however, canes are often kept in large shocks for one to two weeks after cutting. When a heavy frost occurs the sorghum should be cut and placed in large shocks at once. If it is to stand for some time, both leaves and heads should be left on. In large shocks, with cool weather the sorghum may be kept' with little loss for three or four weeks. A heavy freeze will do no harm provided the cane can be ground at once upon thawing ; but after thawing it is likely to go out of condition in a very short time. 271. An average yield of green sorghum would be 8 to 10 tons, though it may vary from 5 to 15 tons. The yield of sirup depends on the kind of mill, quality of the sorghum, and quality of the juice. A poor mill may extract only 30 per cent of the total juice, while with a good three-roller mill 60 per cent of the original weight may be extracted as juice, or 1200 pounds to a ton of canes. Juice varies in quality, containing 8 to 15 per cent of sugar. The juice is concentrated by boiling until it con- tains about 70 per cent of soUd matter and 30 per cent of 330 CORN CROPS water. The amount of sirup produced from a ton of canes is therefore very variable. In general, a ton of canes will give 700 to 1200 pounds of juice, which in turn will yield 10 to 30 gallons of sirup, according to quality. 272. The manufacture of sorghum sirup consists of three steps : (1) extraction of juice ; (2) clarification of the raw juice ; (3) evaporation of juice. The extraction is done with heavy roller presses of either the two-roller or three-roller type. The juice is then run into settling tanks, where impurities in suspension are allowed to settle out. The clarification is accomplished in some cases by merely allowing the raw juice to settle for some time. Settling is hastened by heating. Sometimes fine yellow clay is added, which aids in settling. When the juice is somewhat acid, lime also is added to the heated juice. After clarification the clear juice is drawn off to be con- centrated. Concentration takes place in large, shallow pans, where the juice is kept boiling by a well-regulated fire. Ordi- narily the pan is divided into compartments, the boihng juice flowing slowly in a thin layer from one end to the other. By the time the outflow is reached, the juice should be concentrated into sirup. In very small plants the juice is merely boiled down in kettles. CHAPTER XXIX BROOM-CORN Broom-corn belongs to the non-saccharine sorghums, resembling Shallu or Kowhang more than others. It is characterized by very short rachis and long, slender, seed-bearing branches. The plant is grown principally for the seed head, or " brush," having practically no forage value. 273. Historical. — The origin of broom-corn is not known, though it was cultivated and used for making brooms two hundred and fifty years ago ' in Italy, where it apparently had its first general culture. References are made to its culture in the United States about the year 1800. The following statement appears regarding it in a book entitled " The Pennsylvania Farmer," published in 1804 : 2 "A useful plant, the cheapest and best for making brooms, velvet whisks, etc. The grain for poultry, etc., a few hills or rows of it in the garden or cornfield suffice for family purposes." While its value was thus recognized, its culture did not become important until several decades later. 274. Statistics of culture. — During the past forty years, broom-corn culture has developed rapidly, as shown by the crop harvested for the past three census years : — Yeab Pounds 1879 29,480,106 1889 38,557,429 1899 90,947,370 ' Mentioned by Casper Bauhin as used for this purpose in 1658. 2 Twelfth Census. Vol. VI, Part II, p. 519. 331 332 COEN CROPS I a i a The crop practically trebled in thirty years. Broom-corn culture has always been concentrated to certain rather limited regions : Four States in 1879 — lUi- nois, Kansas, Missouri, and New York — produced 80 per cent of the crop. In 1889 four States, the first three named above and Nebraska, produced 89 per cent of the crop. In 1 899 the last-named four States and Oklahoma produced 90 per cent of the crop. In 1899 Illinois alone, which has been the leading State in broom-corn production for forty years, produced 66.7 per cent of the entire crop in the United States, while 50.1 per cent of the entire crop was grown in three counties. The twenty-two counties of the United States produC' ing more than 1000 acres each are shown in the fol- lowing table, as reported by the Twelfth Census : — Fig. 115. — Broom-corn, sorghum, and hybrid between the two : li, broom-corn ; 6, hybrid ; c, black-seeded sorghum. p'M BBOOM-CORN 333 County State ACKES Pounds Produced AVEEAUB Yield PEK Ague Coles . . . Illinois 34,597 23,948,030 692 Douglas . . -. Illinois 22,356 14,768,780 661 Moultrie . . . Illinois 10,256 6,815,530 665 Cumberland Illinois 6,619 2,738,710 414 Edgar . . lUinois 6,248 4,085,860 664 Woods . . . OMahoma 6,086 1,292,670 212 McPherson . . Kansas 6,684 2,890,330 609 Reno .... Kansas 5,137 1,691,090 329 Rice .... Kansas 4,167 1,366,030 328 Henry . . . Missouri 3,753 1,177,950 314 Shelby . . Illinois 3,246 1,826,670 663 Clark . . . lUinois 2,446 1,210,140 495 Henry lUinois 2,000 1,298,450 649 AUen . . . Kansas 1,952 566,480 290 Cass . . Nebraska 1,726 776,580 450 Stafford . Kansas 1,684 553,710 329 Jasper lUinois 1,496 651,560 436 Piatt . . Illinois 1,454 950,710 654 Sheridan Kansas 1,307 305,910 234 Cheyenne . . Kansas 1,090 252,940 232 Stevens . . . Kansas 1,054 267,680 264 Polk .... Nebraska 1,051 498,000 474 275. Varieties. — Seedsmen list broom-corn under at least a dozen variety names, but these names have littlq significance. There are two types, known as (1) stand- ard, normally growing about 12 feet high with a brush 18 to 28 inches in length, and (2) dwarf broom-corn, growing 4 to 6 feet in height and producing a brush 12 to 18 inches in length. The standard type is used for the manuf actiire of large brooms. While dwarf brush is also used to some exteiit in the manufacture of large brooms, the straw is generally too 334 COBN VBOPS fine and weak for this purpose. The dwarf type, however, is almost exclusively used in whisk brooms. There is some variation in different strains. Very often the large manufacturers keep on hand seed of the strains best suited to the needs of the trade, and are ready to supply growers with this seed. 276. Brush. — The brush should be bright and of a uniform light green color. When the head does not fully exsert from the " boot," or upper leaf sheath, the base of the brush is likely to take on a red color, which is very undesirable. . The discoloring is most common when con- siderable rain occurs during the maturing season. This is a very common fault of the dwarf variety and necessi- tates breaking over the brush as soon as it is well grown so that it will hang down. For this reason dwarf broom- corn is more successfully grown in rather dry climates, most of it at present being cultivated in Kansas and Oklahoma. Length of brush. — In general, the longer the brush the better, all other qualities being equal. There is some danger that very long brush may be coarse. Brush that is both fine and long is the most valuable. Rachis. — The rachis should be short, with no central " core " of stiff branches extending upward in the center. Shape of head. — The head should be broom-shaped rather than conical, with all branches approximately the same length. Flexibility. — The brush should be flexible and tough. This condition is attained both by proper climatic condi- tions and by proper harvesting. 277. Culture of broom-corn. — The selection and prepa- . ration of land, method of planting, cultivating, and so on, are no different in general from those in the culture of BBOOM-COBN g85 other sorghum crops. How^yer, quaUty and uniformity in the crop is as important as yield, and more precaution must therefore be taken to have the land uniform, and the Fig. 116. — Poor and good heads of standard and dwarf broom-corn (after C. P. Hartley) : a, poor head of dwarf with large center ; 6, head of dwarf inclosed in " boot " ; c, good grade of dwarf for whisks ; d, long head of dwarf with characteristic weakness at point x ; e and /, good grades of standard hurl ; g, good head of self-working; h, poor grade of standard because of heavy center ; i, smutted head. stand uniform. Also, the cost of harvesting is much increased if the crop does not ripen so that it can all be harvested at one time. 336 COUN CHOPS Land. — Any productive soil will raise broom-corn. The principal consideration is that the soil be uniform. One reason why the culture of this plant has been so suc- cessful in central Illinois is because of the extensive areas of uniform soil. Planting 278. Time of planting. — The planting of broom-corn usually begins about two weeks later than the planting of field corn and may be continued for a period of four weeks. In the Central States, planting is done from the middle of May to the end of June and harvesting begins the middle of August. It is often desirable to distribute the planting so that the harvesting will not come too much at one time. Method of planting. — The width of row varies from 3 feet for dwarf varieties to 3| feet for standard varie- ties. The distance apart in row is 2 inches in dwarf and 3 inches in standard varieties. The planting should be uniform, as the brush will be too coarse where the stalks are thin, and undersized where the planting is too thick. Drilling is the ordinary method of planting. The ordi- nary corn-planter, with special plates for broom-corn seed, is satisfactory. Replanting thin places is not practicable, and thinning the stand is too expensive. It is, therefore, very impor- tant to take every precaution to secure a perfect stand at the beginning. It is hardly necessary to state that the land should be clean and in good tilth, and the seed should be carefully cleaned and of good germinating quality. 279. Tillage. — The same tools and methods of cultiva- tion that are successful with Indian corn are effective with broom-corn, except for the fact that broom-corn is more BROOM-COBN 337 delicate and grows slowly the first three weeks, necessitat- ing greater care and skill. 280. Time of harvesting. — In order to get a good green color and tough, flexible brush, the corn must be cut quite green, or just as soon as the brush has reached full growth. , The best time is when just past full bloom. If allowed to ripen, the brush loses color and becomes brittle, and the selling price for such brush is often less Fig. 117. — Standard broom-corn, tabled and ready for hauling. than one-half that of high-grade stock. On the other hand, when allowed to ripen, 10 to 20 bushels of seed per acre is secured, which is valuable as a poultry and stock food. It is generally conceded that the loss in value to the brush is much greater than the value of the seed crop, although in California the seed crop is quite generally harvested ; but this is not customary in other places. Cutting the brush. — Dwarf broom-corn is usually " pulled," while the standard type is " tabled " and cut. Dwarf varieties are short enough so that a man can easily reach the heads; also, the base of the brush is inclosed in the " boot," which must be removed. When the crop is uniform enough so that all can be pulled at one z 338 COBN CROPS time, the cheapest way is to pull and load directly on wagons. When it must be pulled twice, that harvested the first time over is laid on the ground and covered with leaves. It is not possible to get a uniform grade in this way. Standard broom-corn is first " tabled " and the heads are then cut by hand. In tabling, one man passes backward Fig. 118. — Threshing broom-corn heads or brush. between two rows, bending the stalks at a point about 30 inches above the ground toward each other and across the row, so that the heads hang about two feet past the other row. Two men following cut off the heads and place them evenly, on every other table. Three men can harvest about two acres per day.. Later, a team with a wagon passes over the empty tables and the brush is collected. Threshing and storing. — The heads are threshed directly from the field, or within a very few days after BBOOM-COBN 339 cutting. The thresher removes all seeds, after which the brush is stored in drying sheds, in thin layers about 3 inches deep. Bulking. — After drying for about three weeks the brush is piled in tiers, called " bulking," for further drying. It Fig. 119. — Power baling press for broom-corn. then goes " through the sweat," which means merely that considerable natural heat is developed and the drying is hastened. Baling. — This should not take place until the brush is thoroughly dried. Good bales of brush are often very- much damaged by heating and molding, as a result of baling before dry. A bale weights 300 to 400 pounds. 340 COBN CROPS 281. Market grades. — Certain trade terms are applied in describing the qualities of broom-corn, which are well Fig. 120. — A bale of broom-corn. understood by those famihar with the stock. The fol- lowing data, prepared by C. P. Hartley, give trade terms and relative prices of different grades : — . Cents per Pound Fair, crooked IJ Good, well-handled, crooked . . 2 Fair, medium, red-tipped 34 Slightly tipp d, smooth growth .... . . 4 Good, green mooth, self-working 44 Choice, green, self-working carpet stock ... 6 Fair, medium, sound hurl 34 Good medium hurl ... 4 Good, green, smooth, carpet hurl 5 Choice, green, smooth, carpet hurl 54 BttOOM-COBN S4l REFERENCES ON SORGHUMS Bureau of Plant Industry, United States Department of Agri- culture : — Bulletin 50. Three Much Misrepresented Sorghums. Bulletin 175. The History and Distribution of Sorghums. Bulletin 203. The Importance and Improvement of Graiu Sorghums. Bulletin 237. Grain Sorghum Production in the San Antonio Region of Texas. Farmers' Bulletins, United States Department of Agriculture :— Bulletin 37. Kafir Corn Characteristics and Uses. Bulletin 50. Sorghum as a Forage Crop. Bulletin 92. Improvement of Sorghum. Bulletin 174. Broom Corn. Bulletin 246. Saccharine Sorghums for Forage. Bulletin 288. Non-saccharine Sorghums. Bulletin 322. Milo as a Dry Land Crop. Bulletin 334. Sorghum for Silage. Bulletin 448. Better Grain Sorghum Crops. Bulletin 450. The Best Two Sweet Sorghums for Forage. Bulletin 477. Sorghum Sirup Manufacture. Kansas Agricultural Experiment Station Bulletins : — Bulletin 23. Smuts of Sorghum, Corn Smut. BuUetin 93. Kafir Corn. Bulletin 99. (Page 5.) Kafir Corn, Alfalfa Hay, and Soy Beans for Pork. BuUetin 99. (Page 32.) Bulletin 99. (Page 35.) Corn. BuUetin 119. BuUetin 119. Bidletin 119. Kafir Corn. Digestion Experiments with Kafir Kafir Corn vs. Good Butter. Sorghum Pasture for Dairy Cows. Whole Kafir Corn Compared with (Page 28.) (Page 42.) (Page 63.) Ground Kafir Corn for Growing Calves. BuUetin 136. (Page 164.) Sorghum with Corn for Baby Beef. Bulletin 136. (Page 179.) Kafir Corn Meal and Sorghum Seed Meal with Soy Bean Meal for Swine. BuUetin 136. (Page 202.) Kafir Corn with Alfalfa for Baby Beef. 342 CORN CROPS Bulletin 149. Prevention of Sorghum and Kafir Corn Smut. Oklahoma Agricultural Experiment Station Bulletins : — Bulletin 22. Field Experiments with Kafir Corn. Bulletin 35. Summary of Digestion Experiments with Kafir. Other Bulletins : — Florida Agricultural Experiment Station, Bulletin 92. Sorghum for SUage and Forage. Ohio Agricultural Experiment Station, Bulletin 21. Sorghum. Georgia Agricultural Experiment Station, Bulletin 86. Sor- ghum vs. Corn Meal as a Source of Carbohydrates for Dairy Cattle. Iowa Agricidtural Experiment Station, Bulletin 55. Field Experiments with Sorghum. American Breeders' Association. III. Breeding of Grain Sorghums. Bureau of Entomology, United States Department of Agri- eultm-e. Bulletin 85. The Sorghum Midge. South CaroHna Agricultural Experiment Station, Bulletin 88. Sorghum as a Sirup Plant. Nebraska Agricultural Experiment Station, Bulletin 77. Poisoning of Cattle by Corn or Sorghum, and Kafir Corn. Texas Agricultural Experiment Station, Bulletin 99. Kafir Corn and Milo Maize for Fattening Cattle. Colorado Agricultural Experiment Station, Bulletin 93. Colorado Hays and Fodder. Texas Agricultural Experiment Station, Bulletin 13. Sor- ghum ; Value as Feed. Effect on Soil. Ohio Agricultural Experiment Station, Bulletin 115. Sugar Beet and Sorghum Investigations in 1899. Delaware Agricultural Experiment Station, Bulletin 44. Sorghum in 1898. Delaware Agricultural Experiment Station, Bulletin 27. Tests of Sorghum Varieties. New Mexico Agricultural Experiment Station, Bulletin 33. Feeding Non-sacoharine Sorghums. INDEX Acclimation, 117-121. Adaptation and improvement of corn, 74. of sorghum to dry climate, 288. Adjustment of corn plants, 178. Air passages, 35. Alkali resistance, 290. Amber sorghum, 297. Andropogon halepensis, 279. Animal and insect pests of corn, 214— 221. Biological origin, 16. Biotypes, 109. Breads, 252. Breeding close, narrow, broad, 102. Breeding plants, 94. how to conduct, 95. notes, 97. selection of ears, 96. Broom corn, 331-340. classification, 282. Carbon, in composition, 47. Chinch bugs, 218. Chinese maize, 24. Classification corn, 15, 20. by groups, 20-24. broom corn, 282. sorghum, sweet, 281. sorghum, non-saccharine, 282, Climatic factors. in growth of corn, 58-67. in growth of sorghum, 288. Composition of corn, 42. as affected by the rote planting, 183. of parts of plant, 184, 226. as affected by time of cutting, 225. Composition of sorghums, 324. Corn binder, 234. cost of production, 247. crossing biotjrpes. 111. varieties. 111. shows, 253. Corn crop, mineral requirements of, 135. Coyote corn, 20. Crossing sorghums, 287. corn, 111. Crows, 214. Cultivation depth and frequency, 209. methods compared, 206. principles of, 197. tools for, 198. Cultivators for listed corn, 202. two-row, 200. Cultural methods, 158-275. Cutworms, 215. Dent corn, 22. Description corn plant, 26. sorghum plant, 283. Development of varieties, 78. Diseases of corn, 220. Disk harrow, 167. Dominant characters, 105. Drainage, 157. Drought resistance, 286. Drying corn for shipment, 246. Durra, 299, 310. classification, 282. Ear origin, 37. proportion of plant, 228. 343 344 INDEX Ear {continued) relative feeding value, 227. storage, 242. shrinkage, 245. Early culture of corn, 77. methods of modifying, 80. Ear worm, 218. Energy, source of, 47. Environment effect on corn, 118. Erosion, 154. causes of, 155. prevention of, 156. Euchlcena Mexicana, 16. Evaporation of water, 151. from soil under corn crop, 208. Exportation of corn, 4. Fertilization of corn, 52. of sorghum, 286. Fertilizers for corn, 138. formulas, 142. increase due to, 141. use in rotation, 131. when profitable, 144. with farmyard manure, 133. Flint corn, 21. for North Carolina, 187. varieties, 189. Flowers of corn, 36. Fodder shrinkage in curing, 243. Forage corn, sowing for, 171. yield at different rates, 183. sorghum, 294. Gooseneck sorghum, 300. Grain sorghums, 301. Growth of corn, 48. climatic factors, 58-67. length of growing season, 59. relation of sunshine to, 61. rainfall to, 64. soils to, 68. Growth of sorghum relation of climate and soils, 288- 289. Grubworms, 216. Harshberger, J. L., 15. Harvesting corn, 222-248. breeding plats, 97. comparative cost of methods, 241. cost of harvesting tops and leaves, 232. time of, 224. Harvesting sorghum broom corn, 337. for forage, 322. for grain, 319. for sirup, 328. Hermaphrodite forms, 24. History of corn, see Origin of early corn culture, 77. of sorghums, 279. Hoe cake, 252. Hominy, 249. Husker and shredder, 238, Husking fodder corn, 237. Hybridization of corn, 101-116. Importation of corn, 6. Improvement and adaptation, 74-84. of varieties, 85-92. Interculture, principles of, 197-213. International trade in corn, 4. July rainfall and yield, 66. Kafir, 309. Kowliang, 314. Leaves of corn, 33. composition of, 184, 227. percentage, 226. stripping, 230. turgidity, 39. Lime, 147-149. application of, 134. effect of, 147. Lister, 168. Listing, 169. Manure, farmyard for corn, 130. value the ton, 132. Marketing, 245. Market movement, 11. INDEX 345 Mass selection, 88. results with, 89. Meal, corn, 249. Mendel's laws, 104. Milo, 311. Mineral matter for corn soils, 135-150. Moisture in corn, 175. Natural selection, 83. Nitrogen for corn, 134, 146. Non-saccharine sorghums, 301. classification of, 291. region cultivated, 303. statistics, 304. Orange sorghum, 298. Organic matter of corn soils, 130. Origin of corn biological, 16. geographical, 15. Origin of sorghum, 279. geographical, 280. Pasture (sorghum), 325. Pedigree selection of corn, 89. Physiology of corn, 38. Physiology of sorghum, 286. Plant, corn description of, 26-37. numjjer to the acre, 176. type of, 86. Planter's corn calibrating planter plates, 195. two-row check, 172. lister, 168. Planting corn, 161. checking and drilling, 172. depth of, 175. rate of, 176. on various soils, 180. time of, 173. width of rows, 182. Plowing for corn, 163. Pod corn, 20. Poisoning, sorghum, 327. Poison, for squirrels, 215. Pop corn, 21. products, 251. Preparation of land for corn, 161. Products, corn, 249-251. Production, broom corn, 331. Production of corn as related to climate and soils, 54-73. causes of low, 70. continents, 2. countries, 2. development, 7. how maintained, 134. percentage, 3. restoring, 123. United States, 6. world's crops, 1-2. Production of non-saccharine sor- ghums, 304. Production of sorghum sirup, 295. Rate of planting corn, 176. on different soUs, 180. Recessive characters, 105. Relation of climatic- factors to growth, 58. of cropping systems to yield, 122. of July rainfall to yield, 66. of soils to growth, 68. Relationship, degrees of, 101. Relative importance of corn, 1. Root louse, 217. Roots of corn, 26-30. depth, 176. prevent evaporation, 208. spread of, 28. Roots of sorghum, 285. in upper layers, 290. Rootworm, 217. Rotations for corn, 127. Runoff water, 151. Saccharine sorghums, 293-300. classification, 296. introduction, 293. sirup, first grown for, 294. gallons produced, 295. sirup-making, 328^330. Seed corn curing sweet corn, 264. germination tests, 192. grading, 195. 346 INDEX Seed corn (.continued) preparation of, 190. Selection of corn for composition, 91. mass, 88. natural, 83. Self-fertilization, 107. Shallu, 313. Shocks, size of, 235. tying, 237. Show corn, 253-258. Shredding fodder, 238. Shrinkage of ear corn, 244. of fodder in curing, 243. of silage, 243, Silage from sorghum, 326. growing corn for, 212. shrinkage of, 243. time of harvesting, 229. Sirup-making, 328-330. Smut of corn, 220. Soft corn, 22. SoUs as related to growth, 68. classification of corn soils, 70. non-saccharine sorghums, 301. saccharine sorghums, 293. Sowing corn for forage, 171. Squirrels, 214. Stalk cutter, 162. Stomata, number, 35. Stover, feeding value of, 229. relative yield, 228. Style, 51. Subsoiling, 166. Sunlight, intensity of, 62. Sweet com contract with growers, 266. description of, 22. forcing sweet corn, 273. market for, 270. products of, 251. seed, 263. varieties, 262. Teosinte, 18. Tillage comparison of methods, 206. depth and frequency, 209. machinery, 197. reasons for, 205. Tillers, 33. economic value of, 179. factors effecting, 179. Tripsacum dactyloides, 16. Tull, Jethro, 205. Types of corn for different sections, 185. Type of ear, 85. Type of plant, 86. Uses of corn, 249-252. Utilizing the sorghum crop, 324. Value of principal crops, 7. Varieties of corn development of, 78. for different regions, 187. improvement, 85. production by selection, 83. Varieties of sorghum broom corn, 331. for grain, 301. sweet sorghums, 293. Water absorption, 45. given off, 45. loss from fallow soil, 207. loss of, 35. regulating supply of, 151-157. required by months, 152. required for corn, 65, 151. Weeds clearing, 168. effect on yield of corn, 208. Wireworms, 216. Xenia, 103. Yields, corn. ability of corn to, 57. relation to cropping system, 122. to the acre, 7. to the acre, forage, 183. when harvested at different dates, 224. INDEX 347 Yields, sorghum broom corn, 331. forage, 323. grain, 320. sirup, 329. Zea Mays amylacea, 22. canina, 20. curagua, 24. everta, 21. hirta, 23. indeniata, 22. indurata, 21. japonica, 23. saccharata, 22. tunicata, 20. Printed in the United States of America. npHE following pages contain advertisements of a few of the Macmillan books on kindred subjects. Latest Additions to the RURAL TEXTBOOK SERIES Edited by Professor L. H. BAILEY Director of the New York State School of Agriculture at Cornell University Manures and Fertilizers By H. J. WHEELER, Ph.D., D.Sc. Formerly Director of the Rhode Island Experiment Station Illustrated. Cloth, izmo; preparing The clear and unusually full discussion of the practical utilization of manures and fertilizers of all kinds, and of their relations to the plant and to the soil, makes this book not only an excellent text for college students, but also one which will be generally welcomed by all up-to- date agriculturists. All the animal manures, litter, and waste nitroge- nous materials of every sort are discussed. A helpful feature for the student is the extended treatment of the availibility of organic nitro- gen and of the organisms contained in barnyard manure which give rise to the various fermentations taking place therein. The well- known, and also the new, nitrogenous manures such as calcium cyan- amid and calcium nitrate are considered in detail. 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Cloth, i2mo, xx -\- Ji}2 pages, $1.7^ " Farm Management is the study of the business principles in farming. It may be defined as the science of the organization and management of a farm enterprise for the purpose of securing the greatest continuous profit. " Successful farming requires good judgment in choosing a farm and in deciding on a type of farming. It demands clear business organization and management for the efficient "use of capital, labor, horses, and ma- chinery. It requires good judgment in buying and selling. " The change from cheap land, hand tools, and farming to raise one's own food and clothing, to farming as a commercial undertaking has come upon us so suddenly that business principles are not always well under- stood by farmers. Nor do those who understand the application of such principles to city conditions often know how to apply them on the farm. 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The various breeds are discussed in such a way as to enable the reader to select the kind that is most likely to do well under his conditions and to acquaint him with the care it is accustomed to and needs. The management of the flock in the fall, winter, spring, and summer seasons, the formation of the flock, the selection of foundation stock, and the means of maintaining a high standard of flock efficiency are all discussed in subsequent chapters. Principles of Fruit Growing By Professor L. H. BAILEY JVew edition. Cloth, ismo, $1.^0 Since the original pubhcation of this book, in 1897, it has gone through many editions. The progress of fruit growing in the meantime has been very marked and it has been necessary to completely rewrite the work. The present issue of it brings the accounts of the new practices and discov- eries as they relate to fruit growing up to date. All of the text and practi- cally all of the illustrations are new. 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The author's aim has been at all times to give the pres- ent state of knowledge as supported by the weight of evidence and the opinions of those whose authority is highest. THE MACMILLAN COMPANY Publishers 64-66 Fifth Avenue New York OF KINDRED INTEREST The Farmer of To-morrow By F. I. ANDERSON CUa, i2mo, $1.30 There has been a great deal of theorizing about the " back to the land " movement. It is the purpose of this boolt to crystal- lize and to make practical all of the vague generalizations which have so far been expressed on this subject. To this end the first part of Mr. Anderson's book is given over to a considera- tion of the land itself as a factor in the movement, primarily its economic bearing on the question. 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WARREN, Professor of Farm Management and Farm Crops, New York State College of Agriculture at Cor- nell University Cloth, i2mo, 4^6 pages, $i,io Written by Professor G. F. Warren, who is in charge of the Department of Farm Management and Farm Crops in the New York State College of Agri- culture, Cornell University, an authority on questions pertaining to practical agriculture. Professor Warren is, moreover, a farmer. He grew up on a farm in the mid- dle West and is living at the present time on a farm of three hundred and eighteen acres, which he supervises in connection with his work at the Univer- sity. The " Elements of Agriculture " is a text that does not " talk down " to the pupU. It gives agriculture rank beside physics, mathematics, and the languages, as a dignified subject for the coiurse of study. In Warren's " Elements of Agriculture " there is no waste space. 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Bailey's Fruit-Growing ....... 1 50 L. H. Bailey's The Pruning Book 1 50 F. W. Card's Bush Fruits 1 50 On the Care of Live-stock Nelson S. Mayo's The Diseases of Animals . W. H. Jordan's The Feeding of Animals I. P. Roberts' The Horse M. W. Harper's Breaking and Training of Horses George C. Watson's Farm Poultry . 1 50 1 50 1 25 1 50 1 25 On Dairy "Work, Farm Chemistry, etc. Henry H. Wing's Milk and Its Products .... 1 50 J. G. Lipman's Bacteria and Country Life .... 1 50 On Economics and Organization I. P. Roberts' The Farmer's Business Handbook . . 1 25 George T. Fairchild's Rural Wealth and Welfare . . 1 25 H. N. Ogden's Rural Hygiene 1 50 J. Green's Law for the American Farmer .... 1 SO THE MACMILLAN COMPANY PUBLISHERS 64-66 Fifth Avenue NEW YORK Cyclopedia of American Agriculture Edited by L. H. BAILEY Director of the College of Agriculture and Professor of Rural Economy, Cornell University. With 100 fuU-page plates and more than SftOO Ulustrationa in the text; four volumes; the set, $80.00 half morocco, $3S.OO carriage extra Volume I— Farms Volume in— Animals Volume n— Crops volume rv— The Farm and the Community "Indispensable to public and reference libraries . . . readily comprehensible to any person of average education." — The Nation. "The completest existing thesaurus of up-to-date facts and opinions on modem agricultural methods. It is s^fe to say that many years must pass before it can be surpassed in comprehensiveness, accuracy, practical value, and mechanical excellence. It ought to be in every library in the country." — Record-Herald, Chicago. Cyclopedia of American Horticulture Edited by L. H. BAILEY With over $,800 original engravings; four volumes; the set, $^.00 half morocco, $SS.OO carriage extra "This really monumental performance wUl take rank as a standard in its class. Illustrations and text are admirable. . . . 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