f\ n.7!/-S> U. S. DEPARTMENT OF AGRICULTURE, BUREAU OF PLANT INDUSTRY Circular So. 13. B. T. G \l.l."\\ AY Chief of Bureau. THE WORK OF THE SAX ANTONIO EXPERIMENT FARM IX L90T. FRANK B. HEADLEY, Scientific Assistant, \NI) STEPHEN II. HASTINGS, Farm Superintendent, Western Agricultural Extension Investigations. . i l'i ;: ; cir. 13 "^ WASHINGTON : COVE'..' . OTFICE : 1908 S. DEPOSITORY BUREAU OF PLANT INDUSTRY. Physiologist and Pathologi t, and Chief of Bureau, Beverly T. Gallowaj . Physiologist and Pathologist, and Assistant Chief of Bureau, \ 1 1 >ert I". Woods. Laboratory o) Plant Pathology, Erwin I Smith, Pathologist in Charge. Investigations of Diseases of Fruits, Mertoii B. Waite. Pathologist in charge. Laboratory of Forest Pathology, Haven Metoalf, Pathologist in Charge. Cotton inn/ Truck Diseases and Plant Disease Surrey, William A. Orton, Pathologist in Charge. Plant J. Hi History Investigations, Walter T. Swingle, Physiologist in Charge. Cotton Breeding Investigations, Archibald D. Shamel and Daniel N. Shoemaker, Physiologists in Ch.i i Tobacco Investigations, Archibald l> Shamel, Wightman W. Garner, and Ernest II. Mather Charge. Corn Investigations, Charles P. Hartley, Physiologist in Charge. Alkali and Drought Resistant Plant .Breeding Investigations, Thomas II. Kearney, Physiologist in Charge. Soil Bacteriology ami Water Purification Investigations, Karl F. Kellerman, Physiologist in Charge. Bionomic Invt ligations of Tropicaland Subtropical Plants, Orator F. Cook. Bionomist in Charge. Drug and Poisonous Plant Investigations and Tea Culturt Investigations, Rodney II. True, Physiologist in Charge. Physical Laboratory. Lyman J. Briggs, Physicist in Charge Crop Technology and Fibt r Plant Investigations, Nathan A. Cobb, Crop Technologist in charge. Taxonomic mat Rangi Investigations, Frederick V. Coville. Botanist in Charge. Farm Management Investigations, William I Spillman, Agriculturist in Charge. Grain Investigations. Mark Alfred Carleton. Cerealist in Charge. Arlington Experimental Farm, Lee C. Corbett, Horticulturist in Charge. Vegelablt Testing Gardens, William W. Tracy, sr.. Superintendent. Sugar-Bccl Inn sligations Charles 0. Townsend Pathologist in Charge. Western Agricultural I tit n ion Invi stigation Carl S. Scofield, Agriculturist in Charge. Dry-Land Agriculture Investigations E Channing Chilcott, Agriculturist in Charge. Pomological Collections, Gustavus B Bracket) Pomologisl in Charge Field Investigations in Pomology. William A. Taylor and G. Harold Powell, Pomologists in Charge. Experimental Gardens arid Grounds, Edward M Byrnes Superintendent Foreign Seed and Plant Introduction, David Fairchild Agricultural Explorer in Charge Forage Crop I mi sligations Charles V. riper, Agrostologist in Ch Seed Laboratory, Edgar Brown, Botanist in Charge Grain Standardization, John D Shanahan, Crop Technologist in Charge. Subtropical Laboratory and Garden, tfiami.Fla. Ernst \ Bessej Patl i I in Charge. Plant Introduction Garden, chico, Cat., W W. Tracy jr., Assistant Botanist m Charge, South Texa Caidiit Urownsrilli 7V/ rdwurill' Green Pomologist in Chargi Farmi r, Cooperativt D< monstration War/.. Seaman A. Knapp Special Igent in < barge. Seed Distribution (directed by Chief of Bureau) Lisle Mori • tan t in General Charge. Editor, i. i: Rockwell. rln. i i I, 1 1; lames E. Jones. [Cir. 13] 2 B. P. I THE WORK OF THE SAN ANTONIO EXPER MENT FARM IN l!H)7. INTRODUCTION. Although San Antonio is one of the oklesl cities in the Stal Texas, agriculture in it- vicinity has nol been continuously successful except with irrigation. To observers acquainted with semiarid con ditions in other States, the amount of rainfall, the soil, and oilier natural conditions indicate thai this section should be well adapted to dry farming. The rainfall, were it well distributed, would be suffi- cient for bountiful crops, but a large part of the water is lost through surface run off, since much of the rain comes in violent storms and due- not penetrate readih into the heav^i soils that are characteristic of the region. Severe droughts occurring at irregular intervals and alternating with period- of excessive rainfall have seriously hampered agricult ural de\ elopment. The farms near this city that have irrigation facilities produce abundant crops, showing that the soil is not lacking in fertility. The further extension of agriculture in Bexar County and surround- ing counties depends more than anything else upon catching and holding the rain thai falls. The >oil musl be tilled in such a manner as to permit the rapid absorption of the rain, and the best methods to prevent the loss of water by evaporation must be used. The San Antonio Experiment Farm of the Bureau of Planl [n dn-tr\ was established in order to tesl the practical utility of various tillage methods, and also for the purpose of testing varieties of field - nee .Inly. 1904, the Bureau of Planl Industry lias been operating an e\ perimeut and de istrntion farm near San Antonio, Tex. The farm, which consists of l -'• acres, is owned bj the citj of San Antonio and its use is given to this Bureau withoul charge. The buildings and permanent improvements were furnished by local subscription through tin- Business Men's Club of San Antonio. The aim of the Bureau's work on this farm lias been to ascertain and demonstrate the tillage methods besl suited to successful crop production in this region, which lies near the western and arid limit of the cotton belt, and also i" experiment with new or little known crops thai may be suited to this region. This circular is iutended to give si Uriel' and popular statement of the work of the farm for 1907. B. T. Galloway, Physiologist and Pathologist and Clw ttM. [Cli 4 SAN ANTONIO EXPERIMENT FARM. crops and fruits in order to determine those best adapted to the cli- matic and soil conditions of this section. In connection with these variety-testing experiments many trees, shrubs, and field crops im- ported from foreign countries are being grown. LINES OF WORK UNDERTAKEN. The following are the most important lines of work under way. a large part of which is in cooperation with other office- of the Bureau of Plant Industry: Tillage experiments, rotation experiments, cul- tural experiments with cotton, finding a method of eradicating John- son grass: acclimatizing weevil-resisting type- of cotton, in coopera- tion with the Office of Bionomic Investigations; tests of forage crops, in cooperation with the Office of Forage Crop Investigations ; tests of grain crops, in cooperation with the Office of Grain Investigations; investigating the cause of the sterility of sorghum, in cooperation with the Agronomist in Charge of Grain-Sorghum Investigations: and tests of horticultural crops, in cooperation with the offices of Seed and Plant Introduction and of Field Investigations in Pomology. TILLAGE EXPERIMENTS. The soils in the vicinity of San Antonio are mostly heavy clay and so compact that they absorb water very slowly. To make them more open and porous, several methods of tillage not ordinarily practiced by farmers are being tried. The more important features of the method- tested last year were dee]) plowing, plowing in early autumn rather than in the spring, the addition of manure or other organic matter, and the maintenance of a dust mulch. DEEP PLOWING AND M BSOI1 INC. Deep plowing and subsoiling loosen the -oil to a depth of 1_ inches or more, so that both water and air can easily enter. In addition to catching more of the rainfall, the subsoiled ground allows a deeper and more healthy growth of the root- of plants. In experi- ments with cotton and corn in L907 four plots of subsoiled ground yielded more in rvcvy case than an equal number of plots not sub- soiled. A series of moisture determinations made during the grow- ing season failed to -how any appreciable difference, however, in tie' moisture condition of the two series of plots. It costs almost twice as much to plow and subsoil land as it does to plow it alone. The results so far obtained are not adequate to serve as a basis for an estimate as to whether this increase in yield is suffi- cient to repay the additional cost of subsoiling. There is reason to believe, however, that the effects of subsoiling may be evident in crops for several years. [Cir. 13] SAN \N rONIO EXPERIMENT FARM. 5 I \];].\ I All. PI uu i HG. It has been common experience in semiarid farming that, where it can be 'I early fall plowing gives better results than plowing in the spring immediately before planting, yet this practice is by no means generally followed in the vicinity of San Antonio. It takes an extra amount of power t<> plow the land when it is hard and dry, usually is in the late summer after crops have matured, so that the temptation is strong to put off plowing until the ground has been softened by rain. When rain falls on hard, unplowed ground much iih.it ol' it is lost l>'\ surface run-off than when it falls on loose, plowed land. For this reason fall-plowed land usually shows a greater soil moisture contenl than spring-plowed land. In October, 1907, a portion of a field of sorghum was plowed, the other part being left unplowed until December. In the mean time more than 7 inches of rain had fallen, and soil moisture determina- tions made in December showed that in the first 3 feel of the land plowed in October there was 24.9 per cent of water, while the land plowed in December contained for the -a me depth 22.6 per cent. This was a saving equivalent to Id inches of rain actually absorbed and held as a result of the earlier plow ing. There are. of course, many local factor- that must be taken into account in determining the besl time to plow in any region. The important thing i- that when the land is not actually in crop the surface should be kept in the best possible condition to absorb and retain any rain that fall-. Tin- i- not merely good farm practice; it i- absolutely necessary to insure crop production in the San Antonio region. MANURING. Either the application of barnyard manure or the plowing under of green crop-, besides increasing the -oil fertility, has a tendency to loosen the soil aid to put it into much better condition for the absorption and retention of water. It i- true that a heavy dressing of stable manure apparently dries out the -oil. particularly if the manure i- coarse. This i- because such manure both ventilates the -oil ami actualh absorbs water from it. din- effect i- immediate hut not permanent. Although it may dry out the soil to some extent at first, at the same time the manure put- it into hetier condition for tin' absorpti f moisture. When heavy rain- fall upon manured land it may accumulate more moisture than unmanured land. This peculiarity of manure to at lir-t dry out the -oil make- it quite necessary in a dry climate t<> apph it in the fall or early winter lather than in the spring. Bad effects from drought are likely t" follow if the manure he added I nit a short time he lure seeding. ■ [Cli SAN ANTONIO EXPERIMENT FARM. I ill DTJS1 Ml I .( II. Direct evaporation from the soil can be checked by keeping the upper 2 or 3 inches of the surface well cultivated, so as to form a dust blanket, or dust mulch. When the ground is kept covered with a thick layer of dry, loose soil, evaporation is slight, but when the soil surface is not kept dry and loose, evaporation goes on very rapidly. The tools required for maintaining the dust mulch are a common barrow, a vveeder, and various form- of cultivators. The fact that the -oil in the vicinity of San Antonio is heavy, together with the comparative rarity of high winds, makes it possible to maintain an effective dust mulch and to accumulate in the soil' enough moisture to carry a crop to maturity even if little rain falls during it- growth. After the dust mulch has been destroyed by a rain, evaporation from the supply of water in the soil begins as scion as the rain ceases, and in cases where the weather immediately following the rain is hot and windy this loss of moisture becomes exceedingly "Teat. On the heavy soils of San Antonio a light rain, as for instance 0.1 to 0.-1 inch, reduces rather than increases the total amount of soil water. This is apparently due to the fact that such lighl rain- are only suf- ficient to establish capillary connection between the surface soil and the moisture in the lower soil, and before the surface is dry enough to permit cultivation some of the moisture has been drawn from the supply below and dissipated into the air. A rain of less than 0.1 inch is usually insufficient to establish such capillary connection, and is therefore harmless. Even a heavy rain, mile-- followed immedi- ately by cultivation to renew the dust mulch, may result in a reduc- tion rather than in an increase of the amount of -oil moisture. Such a case i- illustrated by Tahle I. Table I. — Soil moisture in mi orchard and i h In for: . Orchard. field. Moisture, Moisture, May 28. JuneG Moisture, May 28 \l ii lure, l 3 Average- Per a ni . Pi i , 22.3 22.2 21.2 i 19 6 17.8 1'ir cent . 18 3 18 I i i e cent. :0.o 18.6 21.0 20.4 17.4 On May 29, 1.2 inches of rain fell, which should have raised the moisture content of the upper 3 feet of soil 2.7 per cent had it all been absorbed. Seven day- after the rain, in the absence of a dust mulch, the moisture content of the first 3 feet in the orchard was 0.6 per cent less than it had been before the rain. Had this held been [Cii\ L3] SAK ANTONIO EXPERIMENT FARM. i harrowed two or three day- after the rain there would have been an increase in the amount of water in the soil instead of an actual de- crease. In a near-bj field of corn which was cultivated two days earlier than the orchard there was an increase of O.C per cent of moisture over what was in the soil May 28. WIXTEK I'M. I. VGE. Not only is it important to keep a well-established dust mulch on all cultivable land throughout the summer, but effective measures should I"' taken in catch and bold all the moisture possible that may fall during the winter. In cold climates, where the soil remains frozen, but little tillage can be given. The San Antonio climate. however, is comparatively warm in w inter, so that much soil moisture may be lost by evaporation unless the ground is harrowed or culti- vated so as to establish a dust mulch after rains. The usual method is to stir the surface of the ground as soon as it can be worked after each rain. Winter harrowing of fallow land maj seem to be an expensive operation, but in this region it is very likely to make the difference between success and failure, and the ex- pense is really not verj great where proper tools are used. Table II -how- the results of soil-moisture determinations made on March 12, 1908, on two fields, one of which was fall-plowed and kept well tilled throughout the winter and the other plowed in February. These plots bore the same kind of a crop in L907, and the moisture condition in the autumn was probably alike in both. It will be noted that the upper foot of soil of the winter-tilled plot retained :'>. I per cent re moisture than the plot that was left without cultivation until February. Tabu II. -Soil moisture on March I.'. 1908, in tico m Ids at San Antonio, Tt /.. om of which irn.s /ilmriil during /In prcriottx autumn and flic other in tin- pt i , i iiinii month. Full plowed Held. Spring- plow ed Held. Average III. 4 Rl I I VI I' >\ >i| CROPS. There are few subject? so much discussed in tlio agricultural papers and at the same time so little understood as the rotation of crop-. It has long been known that continued use of the land for a single crop [Cir. 13] SAX ANTONIO EXPERIMKNT FARM. finally results in reduced yield-, and it is also generally recognized thai alternating two or more crops gives better results than when but one is grown continuously. To find ilif rotations best suited to any given agricultural region is a very complex undertaking and one that takes many years to accom- plish. To find suitable rotation- it is necessary to determine the crops that can be most profitably grown, the order in which they should fol- low each other, and the tillage methods most successful in securing high yield-. The effect of the entire system of rotations, combined with the best tillage methods, should be to maintain or increase the soil fertility. Establishing rotations in the semiarid regions is com- plicated by the fact that they must lie adapted to the conservation of soil moisture. For successful farming in the region of San Antonio not only must the best methods known be used for saving the soil moisture, but it is also important that proper rotation of crops be followed if high productiveness is to be maintained. In order to find practical rota- tions that will keep the soil in condition to give the maximum yields, about forty rotations have been planned and are now being carried on at the experiment farm. To show the method of procedure the following examples are given: Rotation A. Rotation B. RotationC. i lats and vetch. Oats and \ etch • lats and vetch, followed by cowpeas, Cot ton Cotton. Cotton. ( 'mil. i "ii. manured. t '(.in. manured. Tl will lie noticed that only one factor is changed for each rotation. Rotations A and B differ only in the fact that the corn is manured in the latter. After a series of years the results of the manuring should be apparent on all of the crops in Rotation 1>. and the effect of this manure can he determined by comparing the yields in 15 with A. Likewise, the effect of the cowpeas on the yield- of the crops in Rotation C can he determined by comparing C with B. In the same way. by changing one factor at a time in the rotation, we may compare the effects of deep and shallow plowing, of fall and spring plowing, and may determine (he value of disking and liie effect of plowing under green crops. The rotation experiments have been but recently started and it is -till loo early to draw conclusions as to the results, hut it seems certain that (he differences in yield- will he brought out more and i i i i .-, i s\X ANTONIO EXPE] I \i:.M. 9 more distinct h in the years that follow, and the rotation- best suited to the region will be shown. Ml rilOOS "l PREVENTING STERI1 in I \ SORGHUM. Sorghum is one of the commonest forage crops grown in the vicinity of San Antonio, and such varieties as milo and kafir thrive well there and would be profitable as grain crops were it not for the fact that tln'\ can nol be depended upon to produce seed. It has been generally supposed thai unfavorable weather conditions al flowering time was the cause of sterility, which is often complete. The true explanation of this sterility was not discovered until the season of L907, when a special study was made of the problem al a number of places, including the San Antonio Farm. An elaborate series of ex periments was planned, which included planting sorghums al regular intervals during the season and a close study of the weather con- dil ions at Mow ering time. It was found, however, that it was nol the climate thai caused the sterility, but that it was due to the activities of certain minute red- bodied flies {Diplosis sorghtcola) thai infested the sorghum [leads al the time the flowers opened. These insects lay their eggs in the blossoms; from these eggs tiny maggots hatch out, our in each flower, and during their growth these maggots absorb the substance of the newly formed seed. In fourteen or sixteen day- after the eggs are laid these maggots have, in turn, become mature flies. No practical remedy has yel been found for combating the work of this insect, although it is quite possible to secure -<'r>\ by covering the sorghum head- with paper bags before the flowers open. Further investigations concerning the sorghum midge are being carried on and it i- hoped that some practicable method of combating it max be discovered. i i: \nu \ I lo\ i if .n .11 \-o\ GR \--. Johnson gra ! dropogon hah p< nsh Brot.), which may be either a valuable forage crop or a pernicious weed, depending upon how it is controlled, i- an important feature of the agriculture near San An- tonio. This grass perpetuates and spreads itself not only by seed hut by rootsttfeks sent oul beneath the surface of the soil. These root -lock- are capable of sending up a new plant al each joint. It i- on this ace, unit that the grass i- so difficult to exterminate, and any For .i more detailed report <>n tins subject, see "The Sorghum Midge," by Onrie'tou R. Ball. "Science." n. s., vol. 27, up. til 115. January 17. LOOS. r.'i- another method i»f eradication, see Farmers' Bulletin No. 279, entitled ■■ \ Method of Eradicating Johnson ■ trass." [Clr. 13] 10 SAX ANTONIO EXPERIMENT FAEM. method of getting rid of it must be one that will prevent the forma- tion of now rootstocks. It has been found by observing the habits of the plant that new rootstocks do not form until the plant is or 8 inches high or is ready to head out. It is obvious, therefore, that if the plant is never allowed to attain a greater development than this it must die as soon as the last joint of the old rootstock has sprouted or decayed. In the spring of 100G work was begun to eradicate the Johnson grass that wholly covered a large part of the farm and that occurred sporadically on the remainder. At first, attempts were made to rake the roots into windrows on the surface and burn them, but this method proved more expensive and less effective than persistent cul- tivation. It was found that a quicker plan of eradication was to cut the grass off below the surface of the ground as often as it attained a height of 6 or 8 inches. In killing out a meadow, the best results were obtained by plowing the land shallowly in September and sowing to winter oats. During the winter while the grass i- dormant the oats reduce the moisture content of the -oil. so that in the spring when they are cut for hay the ground is left comparatively dry. The resulting growth of the Johnson grass is not so vigorous as on fields left fallow during the winter and is kept down with greater ease by the cultivation follow- ing the removal of the crop. In September, L906, a 6-acre field of Johnson grass meadow was plowed 1 to o inches deep with a disk plow. In November the field was divided into two parts. A and B. Field A contained L' acres and was left fallow during the winter. The cultivation required to keep down the Johnson grass during the months of February. March, and April cost $10.84 per acre for man and horse labor, which is rather too expensive for general practice. In May, when the eradication was nearly complete, this field was sown to German millet. Field B, containing 1 acres, was sown to oats in November. In the spring the Johnson grass grew very vigorously in Field A. hut (lie growth in the oats in Field B was weak, and but few plants headed out before harvesting, which was early in .May. The field was plowed again in dune at a cost of $-_'.7:> per acre, but this should not be charged against the cost id' eradicating the grass, since it left the Held in excellent condition for the following crop. The cos! of cultivation to eradicate the Johnson grass after plowing was only $1.12 per acre. The above treatments were equally efficient in eradicating the grass, but (he difference in cost was entirely in favor of the second method given. [Cir. 13] s\\ VXTONIO EXPER1 \l INI I \l; M. 11 The most useful implement for this work is a 2-horse G-shovel cultivator with sweep attachments. A -mall L-horse cultivator with similar sweeps does a- good work a- the large one, bul is of course more expensive, since one man can not accomplish a- much in a day. When iIm grass occurs only in -mall scattered spots, cultivation of the whole field becomes unnecessary. These spots can lie cleaned up by keeping the grass cut down with a garden lioe. Digging out the roots in such spots (a plan followed by some farmers) i- no more effective than cutting <>!l the plants and i- much more laborious and expensive. In attempting in eradicate Johnson grass by any method the work must he thoroughly done, for it' any plant- he allowed to approach maturity all the previous work is lost. Thorough culti- vation will kill out i he grass. Careless cultivation makes it grow more \ igorously. I Rl a'- l OR l' a: VGE l\H GREEN M \ \ I RE. There i cms lack of suitable forage crop- in the region about San Antonio. In the drier seasons not enough forage is produced to supply the local demand and it becomes necessary to have supplies brought in from outside sources. Such a condition i- both undesir able ami unnecessary and tend- to cripple the dairying and stock- raising industries, which should flourish in this region. Johnson grass, sorghum, and winter oat- are at present the most prominent and profitable forage crop- grown. While Johnson grass i- a profitable crop when properly handled, it i- a serious pest where not under control, and the danger of scattering it by feeding is so great that it i- far from being a popular forage crop. Winter oat- make a very desirable (^otl. hut do not seem to he ordinarily profitable enough to induce farmers to raise a sufficient quantity to supply the market. Sorghum yield- well and i- fairly drought resistant, but it is so hard to cure thai farmers do not grow it extensively. A number of experiments in methods of planting sorghum for forage have been tried. The results -how that heavier yield- are obtained, at least in tht tir\ year-, when the sorghum is drilled in row- far enough apart to allow cultivation. In L907 a field of sorghum -own in the manner usually followed by the San Antonio farmer-, that i-. by broadcasting the seed, yielded 1.68 tons per aire, while the same variety of sorghum dialled in row- I feet apart in an adjoining plot yielded '_'.'•» ton- of cured fodder per acre. Sorghum grown in drilled rows has (he disadvantage ol producing a coarser fodder than when -own broadcast, hut in spite "I this the [Clr. 13] 12 SAX ANTONIO EXPERIMENT FARM. tota] yield of digestible dry matter is much greater. "When the sor- ghum is to be put on the market a readier sale may be found for the broadcasted sorghum on account of its liner quality, but for home consumption the drilled sorghum will be found to be the more profit- able crop. When drilled, it may be cut with a corn binder and shocked by hand in the same manner as corn, so that little difficulty is experienced in curing it. .Vetches are winter annuals that may be grown alone or in mixture with oats. There are a few varieties that seem to he adapted to San Antonio conditions. The scarlet vetch (Vicia fulgens) is one of the most promising species so far tried. It is not certain yet that any of the vetches will prove profitable as a forage crop for San Antonio conditions, but they will certainly be valuable in rotation as winter annuals that will improve the soil and yield at least a small amount of forage. No yield tests of forage have yet been made, as all the better varieties under trial w T ere allowed to mature in order to save the seed. Many varieties of cowpeas have been tried. Some of them have proved to be fairly drought resistant and their culture is to be rec- ommended. Cowpeas not only make a very nutritious hay. I nit. like the vetches, are of value in maintaining soil fertility. As the forage yield of eow 7 peas is not usually large they can not lie recom- mended solely as a forage (Top. but rather as a green manure crop to be used in the rotation for their beneficial effects upon the soil. Tin 1 varieties that did best last year on the experiment farm were the Whippoorwill, Iron, and Clay. Some especially drought-resistant strains have been selected from among these varieties ami are being li>ro2:>agalcd. A newly introduced plant from India known as "guar" (Cya- mopis tetragonoloba) has been found very drought resistant. It is a legume, having nitrogen nodules on the roots: hence.it will undoubt- edly prove valuable in increasing the soil fertility. It can at present be recommended for planting only as a green manure crop or as forage for sheep, as other kinds of stock do not readily eat any of the varieties so far tested. Several varieties of clover have been on trial, but so far none have proved to lie sufficiently drought resistant to be of value. Rape was tried for-two seasons, hut both times it was killed out by the harle- quin licet les. so that it can not he considered a success. Alfalfa is not a successful crop in the vicinity of San Antonio when sown in the ordinary manner unless irrigated. In the spring of 1907, in cooperation with Mr. Charles J. Brand, of the Office of [Cir. 13] S \.\ W rON 1" I XPl Ki M I .\ [ FARM. 1 3 Plant Life History [nvestigations, L.28 acres were planted to alfalfa varieties in double-drilled rows 2 feel apart, so as to permit cultiva t ion. These varieties survived the severe droughl of the summer of L907, and in March, L908, the first cutting yielded 1,236 pounds of cured alfalfa haj from the field, a yield equivalent to 957 pounds to the acre. Adjacent plots -own in the ordinary manner that i-. in drills 6 inches apart yielded at the same time at the rate of only :'.l 8 pounds to the acre. This indicates that there is a possibility of growing alfalfa suc- cessfully ncai' San Antonio without irrigation, if ii be planted so as in permit intertillage. Experiments are now under way to determine the i '.<'- 1 practicable method of sowing this crop and of keeping down the weeds when the plants are young. ' R( IPS RAISED FOB URA1 N. There is much need for more grain crops in the vicinity (if San Antonio. Ai presenl nol ei gh grain is raised to supply the local demand. '1 here i- no apparent reason why some varieties of grain should not prove successful in this region, for the average rainfall i> decidedly more than thai of some of the more important grain- producing regions. Ii is possible that the common failure of grain crops may he due to disease and not to the lack of moisture. In such a case it will become necessary to find and use the more disease-resist- ing varieties. Tests are now being made of a number of varietii winter wheat, oats, barley, and rye, and these crops are being watched carefulh to determine whether or nol it is disease or insect pests that cause the comparative sterility and consequent low yield-. No recom- mendation of varieties can yet he made. A- ha- already been pointed out, the use of varieties of sorghiun for main production i- not now possible, owing to the ravages of the sorghum midge. CULTURAL EXPERIMENTS Willi COTTON. Two line- of work are being carried on with cotton. One is in connection with the tillage ami rotation experiments, where yield tests of cotton are being made mi a deep fall plowing compared with -hallow fall plowing, deep spring plowing compared with -hallow spring plowing, and manured land compared with unmanured land: also drill planting compared with check-row planting. In L907 deep plowing yielded better than shallow plowing, fall plowing better than spring plowing, and manured land about the same a- unmanured [Cir. 13] 14 SAX ANTONIO EXPERIMENT FARM. land. Less definite results were obtained from the comparison of drilled and check-row planting, due to the poorer stand obtained from the hill planting, which was done by hand. ACCLIMATIZATION OF WEEVIL-RESISTING TYPES OF COTTON. Experiments arc being made with a considerable series of the weevil-resisting varieties of cotton discovered in Central America by Mr. O. F. Cook." These are being acclimatized and -elected at San Antonio and in several other localities in Texas. The condition- at San Antonio enable the new varieties to display their drought-resist- ing qualities, which prove to be unusually high. They also show, in various degrees, the characters which give them protection against the weevils. After being grown for two years at San Antonio some of the varieties remain nearly sterile, but others are rapidly increasing in fertility and have already overtaken most of the Upland varieties included in the test. Special attention is being given to the selection of a variety of cotton suited to San Antonio conditions by combining as much as possible of the three desirable qualities of large yield, weevil resistance, and drought resistance. HORTICULTURAL WORK. Tests are being made of the varieties of grape-, peaches, Japanese persimmons, apricots, apples, plums, figs, pistaches, olives, and a large number of new fruits and ornamental shrubs and trees that have been introduced by the Office of Seed and Plant Introduction. Altogether about LO acres have been devoted to horticultural work. This line of work is of very great importance, for the tests thus far made indicate that there are many fruit crops well suited to San Antonio condition-. The fruit trees were too young to bear in L907, but most of them should begin bearing in the near future. Tree crops appear to be more especially adapted to dry-land cul- ture than any of the general farm crops, because the trees are usually planted far apart and in such a manner as to permit cultivation of the land iii two directions. Since nearly the entire surface of the ground can he easily kept covered with a dust mulch, the loss by evaporation from the -oil surface i- comparatively -light. Soil moisture deter- minations made during the dry months of 1906 and 1907 showed less ""Weevil-Resisting Adaptations of the Cotton Plant." Bui. SS, Bureau of I'l.-nit Industry. ''• S. Dept. of Agriculture. [Cir i s\X \\ I (>\ h> I \n 1:1 VI I N I FARM. 15 of moisture in the orchards than in field-- planted to any other crop. There are over 100 seedling peache on the farm raised from collected in one oi the dry-land fruit regions of Mexico by Mr. (i. Onderdonk, of Nursery, Tex. These trees have been making rapid growth and are bearing fruit for the first time this season (1908). [n this orchard of seedlings it is hoped thai al least :i few trees will be found thai are well adapted to San Antonio conditions. Any trees that prove exceptionally valuable will be propagated for distribution. The pistache is a nut-producing tree quite extensively grown in -.'me parts of the Old World. The nut i- valuable for the color and pleasing flavor it imparts to confections. All pistache nuts used in the I nited States al the present time are imported. Several hundred trees, embracing a number of wild species brought from pari- of Europe, Asia, and Africa, are on trial at the experiment farm. They arc hardy, have made good growth, and seem to -land drought well. This work with the pistache is conducted in cooperation with the Office of Plant Life Histon [investigations of the Bureau of Plant IihIii-' i\ . CONCLUSIONS. In tho preceding pages the chief lines of work under way at the San Antonio Experinienl Farm have been outlined, and some of the results obtained in L906 and 1907 have been given, h musl be borne in mind, however, that results obtained from the work of one or two year- arc hardly sufficient to serve as a basis for general conclusions. Such experiments must be carried on for several seasons and be sub- jected to diverse climatic conditions before the results can be con- sidered reliable. The chief aim of this circular is to set forth -nine of the agricul- tural problems of the San Antonio region and t<> show how the solu- t ion of these problems is attempted. The crop year of 1907 was one <>l' low rainfall, the total precipita- tion for the vear ended September 1. 1907, being 20.37 inches, while the normal annual rainfall is 29.02 inches; yet the yields obtained on the experiment farm with cotton, sorghum, and corn shovt that even in the driesl seasons fairly good crops can be raised when the best methoi Is of i illagc i re l< •! low ed. A method of exterminating Johnson grass has been practiced suc- cessfully, and the cause of Ihe failure of some sorghum varieties to set seed in this section lias Keen discovered. The satisfactory showing made by many of the varieties of fruit trees under trial would indicate the possibility of a considerable de- [Clr. 13] 1Q SAN ANToNlo EXPERIMENT FARM. fcelopment of fruit production without irrigation. The trees are -till very young, however, and many difficulties now unforeseen may develop as they approach maturity. Detailed investigations have been made as to the effectiveness of various tillage methods in conserving soil moisture and as to the moist me requirements of various crops. UNIVERSITY OF FLORIDA Approved : James Wilson, '"'TlS 0892^9549 ' Secretary of Agricultun . Washington, D. C, July Hi. 1908. [Cir 13] O