CONN 
 
 S 
 
 43 
 
 .E22 
 
 no.235 
 
'At?* ,3^55 
 
 1 
 
 I NJ ' 
 
 CONNECTICUT 
 
 Agricultural Experiment Station 
 
 NEW HAVEN, CONN. 
 
 s 
 
 BULLETIN 235 
 
 FEBRUARY, 1922 
 
 EXPERIMENTS IN DUSTING VERSUS SPRAYING ON APPLES 
 AND PEACHES IN CONNECTICUT IN 1921. 
 
 By W. E. Brittox, M. P. Zavve and E. M. Stoddard. 
 
 Figure 7. Apple Worm 
 or Codling Moth. 
 
 Figure 8. Brown Rot 
 of Peach. 
 
 CONTEXTS 
 
 Page 
 
 Officers and Staff 208 
 
 Experiments in Dusting versus 
 Spraying on Apples and 
 Peaches in Connecticut in 
 
 1021 209 
 
 Apples 210 
 
 Materials used 210 
 
 Cost of Dust Mixtures 211 
 
 Apparatus Used 211 
 
 Number and Dates of Applica- 
 tions 211 
 
 Methods of Recording Data . . 212 
 
 Orchard Xo. I 213 
 
 Orchard Xo. II 214 
 
 Orchard Xo. Ill 215 
 
 Page 
 
 Comparison of Different Sprays 216 
 
 Discussion of Results 217 
 
 Chief Pests Attacking the 
 
 Fruit of Apple Orchards . . . 218 
 
 Insects 218 
 
 Fungous Diseases 219 
 
 Peaches 221 
 
 Mount Carmel Orchard 222 
 
 Cheshire Orchard 223 
 
 Cost of Dusting and Sprajong 
 
 Peach Orchards 224 
 
 Pests of the Fruit of Peach 
 
 Orchards . . .' 22s 
 
 Summarv 226 
 
 The Bulletins of this Station are mailed free to citizens of Connecticut 
 who apply for them, and to other applicants as far as the editions permit. 
 
CONNECTICUT AGRICULTURAL EXPERIMENT STATION 
 
 OFFICERS AND STAFF 
 February, 1922. 
 
 BOARD OF CONTROL. 
 
 His Excellency, Everett J. Lake, ex-officio, President. 
 
 James H. Webb, Vice President Hamden 
 
 George A. Hopson, Secretary Mount Carmel 
 
 E. H. Jenkins, Director and Treasurer New Haven 
 
 Joseph W. Alsop Avon 
 
 Charles R. Treat Orange 
 
 Elijah Rogers - Southington 
 
 STAFF. 
 Administration. E. H. Jenkins, Ph.D., Director and Treasurer. 
 
 Miss V. E. Cole, Librarian and Stenographer. 
 Miss L. M. Beautlecht, Bookkeeper and Stenographer. 
 Miss J. V. Beeger, Stenographer. 
 William Veitch, In charge of Buildings and Grounds. 
 
 Chemistry, 
 Analytical Laboratory. E. M. Bailey, Ph.D., Chemist in Charge. 
 
 R. E. Andeew, M.A., C. E. Shepard, ^ 
 
 H. D. Edmond, B.S., Owen L. Nolan, > Assistant Chemists. 
 
 R. T. Meewin, H. J. Fisher, B.A. j 
 
 Feank Sheldon, Laboratory Assistant. 
 
 V. L. Churchill, Sampling Agent. 
 
 Miss Alta H. Moss, Clerk. 
 
 Biochemical Laboratory. T. B. Osborne, Ph.D., D.Sc, Chemist in Charge. 
 
 Botany. G. P. Clinton, Sc.D., Botanist. 
 
 E. M. Stoddard, B.S., Pomologist. 
 
 Miss Florence A. McCormick, Ph.D., Pathologist. 
 
 G. E. Graham, General Assistant. 
 
 Mrs. W. W. Kelsey, Stenographer. 
 
 Entomology. W. E. Britton, Ph.D., Entomologist; State Entomologist. 
 
 B. H. Walden, B.Agr., M. P. Zappe, B.S., [Assistant 
 Philip Garman, Ph.D., > Entomologists. 
 
 John T. Ashworth, Deputy in Charge of Gipsy Moth Work. 
 Samuel T. Sealy, Deputy in Charge of Mosquito Control. 
 Miss Gladys M. Finley, Stenographer. 
 
 Forestry. Walter O. Filley, Forester. 
 
 A. E. Moss, M.F., Assistant. 
 H. W. Hicock, M.F., Assistant. 
 Miss Pauline A. Merchant, Stenographer. 
 
 Plant Breeding. .Donald F. Jones, S.D., Plant Breeder. 
 
 P. C. Mangelsdoef, B.S., Assistant. 
 
 In charge of the 
 
 Tobacco Station. G. H. Chapman, Ph.D., Windsor, Conn. 
 
Experiments in Dusting versus Spraying on Apples 
 and Peaches in Connecticut in 1921. 
 
 By W. E. Britton, M. P. Zappe and E. M. Stoddard.* 
 
 The series of experiments with dusts in comparison with liquid 
 sprays for controlling the common insect and fungous pests of 
 apple orchards in Connecticut, was begun in 1920, and the results 
 printed in the Report of this Station for that year, pages 168-177. 
 This project, considerably enlarged and including peaches, was 
 continued in 1921. In 1920 the tests were all made in one orchard, 
 while in 1921, experiments were conducted in four apple orchards 
 and two peach orchards, as follows : — 
 
 APPLE ORCHARDS. 
 
 Orchard No. I. Young orchard, Station Farm, Mount Carmel 96 trees 
 
 II. Orchard of W. F. Piatt, Orange 97 " 
 
 " III. Orchard of F. N. Piatt, Milford 524 " 
 
 Old orchard, Station Farm, Mount Carmel . . 40 " 
 
 757 trees 
 
 PEACH ORCHARDS. 
 
 Station peach orchard, Mount Carmel 150 trees 
 
 Peach orchard of M. L. Coleman, Cheshire 113 " 
 
 263 trees 
 
 Originally it was planned to use only the first two apple orchards 
 and the peach orchards, but later we were offered the use of the 
 third apple orchard. We desire to express our appreciation and 
 thanks to the owners of orchards No. II and III and to Messrs. 
 M. L. and Raymond Coleman for their co-operation in this work; 
 also to Mr. B. A. Porter in charge of the Wallingford field station 
 of the Bureau of Entomology, for the use of the dusting machine, 
 and for aiding us in making some of the applications, and in scor- 
 ing the fruit. Mr. George E. Graham of the botanical depart- 
 ment of this Station assisted in applying some of the treatments,, 
 and Messrs. B. H. Walden and Philip Garman of the entomolog- 
 ical department, and F. D. Luddington, E. R. Barton, R. C. 
 Botsford and J. R. Pedersen, temporary employees, aided in 
 gathering and scoring the fruit. 
 
 The owners of the orchards furnished spray outfits with team 
 and driver for each of the spray applications in orchards II and 
 III. 
 
 * The planning of these experiments and the preparation of this paper 
 are the joint work of the writers. The applications were made by Messrs. 
 Zappe and Stoddard, who also supervised and took part in the harvesting 
 and scoring of the fruit. 
 
2 10 connecticut experiment station bulletin 235. 
 
 Apples. 
 
 materials used. 
 Sprays : — 
 
 The liquid spray for all treatments in each of the three apple 
 orchards was made as follows : — 
 
 Liquid lime-sulphur 3 gallons 
 
 Lead arsenate (dry) 3 pounds 
 
 Nicotine sulphate (Black Leaf 40) 24 pint 
 
 Water 100 gallons 
 
 Dusts : — 
 
 SULPHUR-LEAD DUST. 
 
 Powdered sulphur 90 parts 
 
 Lead arsenate (dry) 10 parts 
 
 This dust was used only in the eastern part of orchard No. Ill, 
 and as no treatment was given until after the bloom was over and 
 as aphids and red bugs were rather scarce, the nicotine was 
 omitted. 
 
 SULPHUR-LEAD-NICOTINE DUST. 
 
 Powdered sulphur 90 parts 
 
 Lead arsenate (dry) 10 parts 
 
 Nicotine sulphate (Black Leaf 40) ... 1 per cent. 
 
 This dust was purchased and should have contained one per 
 cent, nicotine sulphate. During the course of making the appli- 
 cations, there seemed to be considerable difference in the color and 
 odor of the material in some of the containers. Assuming that 
 this might mean a difference in nicotine content, samples were 
 submitted for analysis to Dr. E. M. Bailey of the chemical depart- 
 ment, who reported them as follows : 
 
 Sample Nicotine 
 
 No. 1 .29 per cent. 
 
 " 2 .30 " " 
 
 " 3 -84 " " 
 
 " 4 .71 " " 
 
 It will be noticed that none of these samples contained the full 
 amount of one per cent, of nicotine. As it happened, red bugs, 
 aphids, and leafhoppers were not seriously abundant in any of the 
 orchards where this dust was used. 
 
 SANDERS DUST. 
 
 Hydrated lime 86 parts 
 
 Dehydrated copper sulphate . . 10 " 
 Calcium arsenate 4 " 
 
 This dust was used only in orchard No. Ill for the purpose of 
 comparing it with the sulphur-lead dust. 
 
dusting and spraying of apples. 211 
 
 Cost of Dust Mixtures. 
 The 1 92 1 prices for the dust mixtures were as follows: 
 
 Sulphur lead dust and nicotine $13.50 per hundred 
 
 Sulphur lead dust without nicotine ... 8.50 " " 
 Sanders dust 8.00 " " 
 
 In the dusting operations, between three and four pounds of dust 
 were used per tree for each treatment. The cost of dusting an 
 orchard at the present price of materials is about three times as 
 great as spraying even though the time required to apply the dust 
 is very much less than the time required to spray. If the price 
 of farm labor drops it will mean a still greater saving in favor of 
 the liquid spray. 
 
 Apparatus Used. 
 
 The dusting machine used in all three orchards was a Niagara 
 duster owned by the Federal Bureau of Entomology, and used at 
 its field station in Wallingford. The machine was constructed to 
 be drawn by a team of horses, but this method was too slow when 
 moving the outfit from orchard to orchard, so the machine was 
 mounted on a Ford ton-truck, thus saving considerable time on 
 the road and in the orchard. The Ford truck had no trouble in 
 pulling this outfit through the orchards (see Plate XIX, a). 
 When the machine was not in use it could easily be unloaded from 
 the truck and stored in a shed. 
 
 An Arlington X. L. gasoline power sprayer was used for apply- 
 ing the liquid spray in orchard No. I. This was a new outfit, 
 and the pressure was not very high, running at about ioo lbs. 
 most of the time. Two lines of hose were used with a single 
 nozzle on each rod. 
 
 In orchard No. II, the liquid spray was applied with a Friend 
 gasoline power sprayer equipped with a tank holding 150 gallons. 
 Two spray rods were used with two nozzles on each rod, and 
 carrying a pressure of about 200 lbs. One man sprayed from the 
 ground and another sprayed from a tower on the spray rig. 
 
 The spray outfit used in orchard No. Ill was identical with that 
 employed in orchard No. II, except that instead of two lines of 
 hose with double nozzles, a single line of hose with a "spray-gun" 
 was used. The pressure was about 175 lbs., which is about as 
 high as can be used without danger of mechanical injury to the 
 foliage. 
 
 Number and Dates of Applications. 
 
 Two treatments after blossoming were given in each of the 
 three orchards. 
 
 Orchard No. I had a delayed dormant spray of lime-sulphur on 
 April 7. On April 21, the pink treatment of spray and dust was 
 
212 CONNECTICUT EXPERIMENT STATION BULLETIN 235. 
 
 applied. The calyx treatment was given on May 18 and 19 and 
 the next or young fruit treatment was made on June 20. 
 
 Orchard No. 1 1 had a dormant spray of miscible oil applied by 
 the owner. The pink treatment was given April 22. The calyx 
 treatment was made May 16, and the next or young fruit treatment 
 was given on June 13. » 
 
 In orchard No. Ill, no dormant treatment was given by the 
 owner, and no pink treatment was made, as it was too late before 
 the orchard was offered to us for experiment. The calyx treat- 
 ment was applied on May 16 and 17, and the next application or 
 young fruit treatment was given on June 14, 15 and 16. 
 
 Method of Recording Data. 
 
 Certain trees promising a crop and situated inside the border of 
 each plot, and representing the chief varieties upon which the tests 
 were made in each orchard, were selected and marked as count 
 trees. In orchard No. I, all trees were used as count trees in 
 obtaining data. In orchard No. II, count trees were as follows : — 
 8 sprayed, 6 dusted, and 7 checks. In orchard No. Ill, the follow- 
 ing number were used as count trees : — 12 sprayed, 12 sulphur-lead- 
 nicotine dust, 8 Sanders dust, and 7 checks. For the sulphur-lead- 
 no nicotine treatment, 2 Baldwin trees were used and a composite 
 sample of Greenings from several trees because the crop on this 
 variety was very light. As a rule the count trees were selected near 
 the center of each plot and not adjacent to a plot having a different 
 treatment, on account of the danger of spray or dust getting on 
 to trees that were not intended to be so treated. With the liquid 
 spray there is little danger of this, but the dust is quite apt to drift 
 or be blown upon adjoining trees. 
 
 The green dropped fruit from each of the count trees was 
 gathered, counted and examined for insect and fungous injuries^ 
 and the data recorded for each tree, at three different times during 
 the season, as follows : July 11 and 12, July 25 and 26, and August 
 8 and 9. At harvest time the picked fruit was scored in the same 
 manner. Each individual apple was carefully examined and a 
 record made of each insect and fungous injury. Apples that 
 were called "good" were absolutely free from any signs of insects 
 or fungous diseases and might better be called "perfect" for they 
 were free from pests and were perfect except possibly as to size. 
 An apple showing the work of more than one pest would be 
 checked as many times # as there were kinds of insect injury or 
 fungous diseases. This very often gave a greater number of 
 injuries than there were apples and in order to get the true amount 
 of any kind of injury all the apples had to be counted, and this 
 number used to compute the percentage of injury or the per- 
 centage of good fruit. This scoring of the fruit involved examin- 
 
DUSTING AND SPRAYING OF APPLES. 2 1 3 
 
 ing separately 150,296 individual apples, equivalent, to about 334 
 barrels. 
 
 The figures given in the tables of results from the various plots 
 are percentages of perfect fruit or of injuries even if very slight, 
 and cannot be compared with any commercial grading. For 
 instance an apple that had been bitten by a curculio might only 
 have one or two small blemishes and would be counted as a "cur- 
 culio" apple, but in a commercial grading of the fruit would easily 
 go as a No. 1 apple. The same is true of other injuries, especially 
 small spots of scab, sooty blotch or fruit speck. After scoring 
 the apples by the above method, all the fruit on several trees was 
 graded as it would be for market. The results obtained by the 
 commercial grading method are of the greatest importance to the 
 fruit grower, and tell at a glance which treatment gives the high- 
 est per cent, of No. 1 fruit. See Plates XVII and XVIII. The 
 other method of scoring is of value in showing just where certain 
 treatments fail. 
 
 The following table has been prepared to show how the different 
 treatments compare by both methods of recording data. 
 
 Scoring for Injuries versus Commercial Grading. 
 
 Scoring Apples Singly Commercial Grading 
 
 
 4-1 
 
 a 
 
 be si 
 
 .2 c 
 
 4-J 
 
 d 
 
 nSg 
 
 4-J 
 
 PI 
 
 
 +5 
 
 
 
 Tree 
 
 •dO 
 
 
 3 u 
 
 
 Ool.T 
 
 bujiU 
 
 H<0 
 
 
 
 hU 
 
 
 
 2 1- 
 
 ■o-g.n 
 
 b in 
 
 •S S 1 - 
 
 l2 en ^ 
 
 A ^ 
 
 A >-< 
 
 £3 1^ 
 
 
 O ID 
 
 <u 
 
 3 a> 
 
 ^ 52 <a 
 
 3.S <u 
 
 O <u 
 
 O d 
 
 3 U 
 
 
 opu 
 
 oSfi 
 
 OP* 
 
 O£0h 
 
 feQPn 
 
 £p« 
 
 Zsh 
 
 OPh 
 
 Oi Sprayed 
 
 48.4 
 
 .4 
 
 42.4 
 
 IO.4 
 
 5.6 
 
 82. 
 
 15.8 
 
 2.2 
 
 B7 Nicotine Dust 
 
 4-95 
 
 .89 
 
 24.9 
 
 21. 1 
 
 83.6 
 
 46.2s 
 
 46.25 
 
 7-5 
 
 Bn Sanders Dust 
 
 •99 
 
 •43 
 
 20.8 
 
 I8.I 
 
 97-5 
 
 60.7 
 
 32.7 
 
 6.6 
 
 Bis & C16 Check 
 
 
 
 8-43 
 
 32.8 
 
 21.5 
 
 97-7 
 
 20. 
 
 60. 
 
 20. 
 
 D8 Sprayed 
 
 33-2 
 
 1.46 
 
 58.5 
 
 9.9 
 
 4-38 
 
 S3- 
 
 14.2 
 
 2.8 
 
 D14 Nicotine Dust 
 
 20.2 
 
 6.81 
 
 61.4 
 
 I2.I 
 
 33-05 
 
 66.3 
 
 22.1 
 
 11.6 
 
 Do. Check 
 
 
 
 19.09 
 
 73-9 
 
 12.6 
 
 100. 
 
 II. I 
 
 33-3 
 
 55-6 
 
 Orchard No. I. 
 
 Orchard No. I was the ten year old Experiment Station orchard 
 located at Mount Carmel. This orchard is just beginning to bear, 
 and consists of 96 trees on a side hill sloping to the west. All trees 
 bearing fruit were used as count trees to check up results. The 
 varieties were Baldwin, Rhode Island Greening, Roxbury Russet, 
 Mcintosh, Gravenstein, Duchess of Oldenburg, Fall Pippin, 
 Northern Spy, Sutton Beauty, King, Wealthy, Hurlbut and Stark. 
 
 This orchard was divided into three plots. The north plot was 
 treated with liquid spray and the south plot with the 90-10 nicotine 
 dust. The remaining plot in the center of the orchard was used 
 as a check. 
 
2-14 CONNECTICUT EXPERIMENT STATION BULLETIN 235. 
 
 NUMBER AND DATES OF APPLICATION. 
 
 The spraying - and dusting in each orchard was usually done on 
 the same day or on the following day if there was not time enough 
 to finish the work on the first day. 
 
 Before the dusting operations began this orchard had a delayed 
 dormant spraying of lime-sulphur on April 7 over the entire 
 orchard. The pink spray was applied on April 21. The weather 
 conditions were very favorable for dusting and spraying on this 
 day, there being a very light breeze from the southeast. The dust 
 flowed very freely and drifted through the orchard for quite a 
 distance. 
 
 The calyx treatment was applied on May 18 and 19. The spray 
 was put on in the afternoon of May 18, the dust on the morning 
 of the 19th. The third treatment or young fruit spray was 
 applied on June 20th. At this time there was no wind and the dust 
 could be blown in almost any direction and would hang in the 
 orchard like a fog. 
 
 RESULTS OF SPRAYING AND DUSTING. 
 
 i %i s si bo •* £? s i S a 
 
 ID ^ <D ^ <D c<D C tfl 0) 0) -4^ ID 
 
 73 O mo .20 gO -S^O S'==oO n O t»oO ?MO 
 
 O <D <D ID P. ID 3 ID O ° ID ->->,d J2 <D o 0) q ,2 <" >-> Q. <" 
 
 OPh rtO, <JPl, OPh I_SPh OOmP-i ooOh ot«0h fcc/jdi 
 
 Spray 39.9 .02 1. 48.2 5.78 10.5 1.28 1.7 .27 
 
 Dust 32.5 .00 .99 55-4 6.48 7.2 7.39 1.39 1.40 
 
 Check 24.8 .078 1.09 55.6 22.0 10.5 12.3 15.7 18.0 
 
 DISCUSSION OF RESULTS. 
 
 The liquid spray gave a higher percentage of good fruit than the 
 dust, and the dust gave more good fruit than where no treatment 
 was applied. With curculio and codling moth the spray gave 
 better control, while with the other chewing insects the dust was 
 a little better and for some unaccountable reason the spray and 
 check plots gave the same result. The amount of aphis and red 
 bug injury was so small that the figures are of no particular value. 
 In the control of the fungous diseases, the spray was of more value 
 than the dust, but the dust was much better than the check. 
 
 Orchard No. II. 
 
 This is the same orchard and some of the same plots of trees 
 that were used in the season of 1920. The orchard is about 27 
 years old and has been very well kept. The varieties in the experi- 
 mental plots were Greening and Mcintosh, Fall Pippin and one tree 
 of Hurlbut. The crop was very light this year. 
 
 There were 97 trees under experiment, 39 in the spray plot, 49 
 in the dusted plot and 9 in the check. 
 
DUSTING AND SPRAYING OF APPLES. 215 
 
 TIME OF APPLICATIONS. 
 
 The entire orchard had a dormant spray of oil which was applied 
 by the owner. The pink spray was applied on April 22 and the 
 first dust treatment was also applied on this date. The calyx treat- 
 ment was made on May 16, both liquid and dust being applied on 
 this day. On June 13, another treatment was given. 
 
 In this orchard fruit was picked and scored from 21 trees, with 
 the following result : 
 
 RESULTS OF SPRAYING AND DUSTING. 
 
 
 *-< 
 
 
 ■£ 
 
 ,2 s 
 
 
 ho ■g 
 
 g 
 
 4-J 
 
 
 s 
 
 -S <u 
 
 5 
 
 — tu 
 
 
 C tfi O 
 
 cu 
 
 rt "" 
 
 
 ■aO 
 
 a O 
 
 .20 
 
 3" 
 
 S'juO 
 
 ^0 
 
 0-,-gO 
 
 
 2 *- 
 
 O D 
 
 T3 u 
 
 Cucu 
 
 3 CD 
 
 O ° cu 
 
 ^1* 
 
 gii 
 
 I^fe 
 
 
 OP-. 
 
 &P-, 
 
 <!ph 
 
 oph 
 
 OS?h 
 
 OOwJm 
 
 a: O-i 
 
 tyjCq?H 
 
 Spray 
 
 48.2 
 
 .04 
 
 .02 
 
 14.7 
 
 1.9 
 
 4-5 
 
 33-3 
 
 .04 
 
 Dust 
 
 19.8 
 
 •78 
 
 .56 
 
 14-3 
 
 2.4 
 
 5-3 
 
 70. 
 
 3.25 
 
 Check 
 
 i-57 
 
 9-7 
 
 .68 
 
 43-7 
 
 12-3 
 
 11.7 
 
 76. 
 
 66.5 
 
 DISCUSSION OF RESULTS. 
 
 As far as the insects are concerned in this orchard, there is not 
 much difference between the dust and the liquid spray. The liquid 
 spray gave over twice the percentage of good fruit. that the dust 
 produced, which difference was largely due to the number of 
 scabby apples in the dust treatment. In this orchard neither the 
 spray nor the dust were very effective in controlling scab, due to 
 the fact that the pink treatment was delayed too long on account 
 of inclement weather. 
 
 Orchard No. III. 
 
 This orchard is located about two miles north of the village of 
 Milford and is divided by a highway running north and south 
 through it. The trees are about 17 years old and are on a fairly 
 level piece of land with woods on two sides. The trees had dense 
 crowns making it rather difficult to reach the centers with spray or 
 dust. 
 
 The varieties in this orchard are Baldwin, Greening, Graven- 
 stein, Mcintosh and Hurlbut. This orchard had no dormant 
 spray, and afterwards had one treatment less than the others, the 
 pink spray being omitted. 
 
 t TIME OF APPLICATION. 
 
 The first treatment was made at the time the petals had all 
 dropped, on May 16 and 17. The second application was given 
 on June 14, 15 and 16. The wind on these days was very strong 
 and the dusting work was delayed a little on this account. 
 
2l6 CONNECTICUT EXPERIMENT STATION BULLETIN 235. 
 
 RESULTS OF SPRAYING AND DUSTING. 
 
 Spray- 
 Sulphur Dust 27.4 
 Nicotine Dust 22.6 
 Sanders Dust 
 Check 
 
 Good 
 
 Red Bug 
 
 Aphis 
 
 Curculio 
 
 Codling Other 
 
 Scab 
 
 Sooty 
 
 Fruit 
 
 Per 
 
 Per 
 
 Per 
 
 Per 
 
 Moth Chewing 
 
 Per 
 
 Blotch 
 
 Speck 
 
 Cent. 
 
 Cent. 
 
 Cent. 
 
 Cent. 
 
 Per Insects 
 'Cent. Per Cent. 
 
 Cent. 
 
 Per 
 
 Cent. 
 
 Per 
 
 Cent. 
 
 44-7 
 
 5-47 
 
 1. 18 
 
 33-9 
 
 5.98 5.98 
 
 4-97 
 
 3-36 
 
 3-28 
 
 27.4 
 
 3-72 
 
 .647 
 
 24.3 
 
 I.85 6.72 
 
 2.08 
 
 34-10 
 
 38.40 
 
 22.6 
 
 12.37 
 
 .706 
 
 40.9 
 
 3-63 9-43 
 
 IO.56 
 
 14.83 
 
 19.70 
 
 16.9 
 
 8.17 
 
 2.03 
 
 36.3 
 
 10.91 11. 13 
 
 13.13 
 
 33.69 
 
 40.70 
 
 4.6 
 
 16.70 
 
 I.24 
 
 60.1 
 
 26.73 30.09 
 
 34-98 
 
 29.87 
 
 35-25 
 
 DISCUSSION OF RESULTS. 
 
 As in the other orchards the spray is again better than any kind 
 of dust. There are no striking differences in the results between 
 the three kinds of dust used. The figures show less scab when 
 sulphur dust was used, but the varieties in this particular plot, 
 Baldwins and Greenings, are not ordinarily very susceptible to scab, 
 especially Baldwins. All kinds of dust were less effective than 
 the spray in controlling the fungous diseases. 
 
 Comparison of Different Sprays. 
 
 In addition to the work on the comparison of dusting and spray- 
 ing, an experiment was conducted on an orchard of 40 forty-five- 
 year old Baldwin and Greening trees at the Station Farm in Mount 
 Carmel in which four different sprays were compared. This 
 experiment has been conducted for three years, but as the 1921 
 results are representative of the two previous season's results, 
 only the work and results of this season will be discussed. 
 
 materials used. 
 
 The sprays used in this experiment were liquid lime-sulphur, 
 dry lime-sulphur, B. T. S., and Bordeaux mixture. 
 
 LIQUID LIME-SULPHUR. 
 
 Lime-sulphur 1 ^2 gallons 
 
 Lead arsenate (powder) ij4 pounds 
 
 Water 50 gallons 
 
 DRY LIME-SULPHUR. 
 
 Dry lime-sulphur 3 pounds 
 
 Lead arsenate (powder) l 1 /* pounds 
 
 Water 50 gallons 
 
 B. t. s. 
 
 B. T. S iY 2 pounds 
 
 Lead arsenate (powder) i 1 /* pounds 
 
 Lime 3 to 4 pounds 
 
 Water 50 gallons 
 
PLATE XVII. 
 
 ■ ■ '*■ ■ . * 
 
 66.; 
 
 11.6 
 
 Harvested fruit from orchard No. I. Sprayed fruit at top, dusted fruit 
 
 in center, and check or untreated fruit at bottom. The percentage of 
 
 fruit in each grade is shown on the labels. 
 
 COMMERCIAL GRADING OF APPLES FROM EXPERIMENT PLOTS. 
 
PLATE XVIII. 
 
 Harvested fruit from orchard No. III. Sprayed fruit at top, Sander's 
 
 dust in second view, sulphur-lead-nicotine dust in third view, and 
 
 check or untreated fruit at bottom. The percentage of fruit in each 
 
 grade is shown on the labels. 
 
 COMMERCIAL GRADING OF APPLES FROM EXPERIMENT PLOTS. 
 
PLATK XfX. 
 
 a. Dusting outfit used in experiments. 
 
 b. Spraying outfit used in orchard No. II. 
 DUSTING AND SPRAYING IN APPLE ORCHARD. 
 
PLATE XX. 
 
 a. Adult moth resting on young apple, twice enlarged. 
 
 b. Stem, calyx and side injury: section of fruit showing larva in burrow. 
 
 Natural size. 
 
 CODLING MOTH. 
 
PLATE XXI. 
 
 a. Adult red bug. Four 
 times enlarged. 
 
 b. Apple injured by red bugs. 
 Natural size. 
 
 c. Curculio egg-scars as they appear at harvest time. 
 Natural size. 
 
 d. Plum curculio side view. 
 Four times enlarged. 
 
 e. Spots on apple leaf caused by black rot fungus. 
 Natural size. 
 
 RED BUG, CURCULIO AND BLACK ROT. 
 
PLATE XXII. 
 
 a. Peach Scab. 
 
 c. Fruit speck of apple. 
 
 b. Brown rot of peach. 
 
 d. Black rot of apple. 
 
 ppipjtf* 
 
 e. Apple scab. f. Sooty blotch of apple. 
 
 FUNGOUS DISEASES OF PEACH AND APPLE. 
 
DUSTING AND SPRAYING OF APPLES. 
 
 217 
 
 BORDEAUX MIXTURE. 
 
 Copper sulphate 1 pound 
 
 Lime 4 pounds 
 
 Lead arsenate (powder) 1J/2 pounds 
 
 Water 50 gallons 
 
 APPARATUS USED. 
 
 All the applications were made with an Arlington X. L. outfit, 
 using two lines of hose and rods with one Friend nozzle to each 
 rod. This outfit maintained a pressure of 125 pounds. 
 
 DATES OF APPLICATION. 
 
 The entire orchard had a delayed dormant spray of lime-sulphur 
 1-9 on April 7. As scab was known not to be abundant in this 
 orchard, the pink spray was omitted. The calyx spray was put 
 on May 19 and the young fruit spray on June 20. 
 
 The following table shows the results obtained. 
 
 RESULTS OF SPRAYS. 
 
 Dry Lime-Sulphur 
 Liquid Lime-Sulphur 53.6 
 B. T. S. 
 Bordeaux 
 
 Good 
 
 Per 
 
 Cent. 
 
 Red Bug 
 
 Per 
 
 Cent. 
 
 Aphis 
 Per 
 Cent. 
 
 Curculio 
 Per 
 Cent. 
 
 Codling Other 
 Moth Chewing 
 Per Insects 
 Cent. Per Cent. 
 
 Scab 
 Per 
 
 Cent. 
 
 Sooty- 
 Blotch 
 Per 
 Cent. 
 
 Fruit 
 
 Speck 
 
 Per 
 
 Cent. 
 
 72.5 
 -53.6 
 
 •13 
 .14 
 
 I.24 
 I.67 
 
 10.70 
 21.76 
 
 .66 
 5-43 
 
 8.7 
 17.70 
 
 •03 
 
 .66 
 
 8.42 
 5-24 
 
 3.64 
 
 2.66 
 
 54-2 
 52.0 
 
 •34 
 
 •25 
 
 3-09 
 1.8 
 
 22.92 
 23.82 
 
 4.92 
 8.29 
 
 11.64 
 n.85 
 
 •34 
 1.78 
 
 13.24 
 9.08 
 
 4-57 
 3-86 
 
 DISCUSSION OF RESULTS. 
 
 In this experiment the dropped fruit was not scored and records 
 were made from harvested fruit from all trees, otherwise the data 
 was taken as described elsewhere in this paper. The check trees 
 did not bear any fruit so no comparison could be made with 
 untreated trees. It will be seen that the dry lime-sulphur gave 
 the highest per cent, of good fruit, this also being true in the two 
 previous seasons' work with this material. Not only was there 
 a higher per cent, of good fruit but the appearance and finish of 
 the fruit was superior to that from the other plots. The B. T. S. 
 gave about the same control of fungous and insect pests as did the 
 lime-sulphur but the fact that it caused considerable injury to the 
 foliage makes it an undesirable material to use. It was estimated 
 that it caused a drop of from 30 to 40 per cent, of the foliage, as 
 compared with no injury from any of the other treatments. 
 
 Usually there has been considerable russetting of the fruit on 
 the Bordeaux plot and probably this year was no exception, but on 
 account of the fact that late frosts caused more or less russetting 
 of the fruit on all of the plots, it was not possible to get any data on 
 this point. Because of its tendency to russet the fruit, we do not 
 recommend Bordeaux as a spray for apples. 
 
2 [8 connecticut experiment station bulletin 235. 
 Chief Pests Attacking the Fruit of Apple Orchards. 
 
 INSECTS. 
 
 Codling Moth: — This is the chief insect attacking apple 
 orchards and though varying in abundance is present every year 
 in every orchard. It passes the winter as a larva in the cocoon, 
 transforming to a pupa in the spring. The moths emerge soon 
 after the trees blossom and lay their eggs chiefly on the leaves, 
 though sometimes on branches and developing fruit. The egg- 
 laying period extends over several weeks, and in about a week 
 these eggs hatch, and the larvae feed slightly on the foliage but 
 tunnel into the fruit mostly through the calyx. They eat their 
 way to the core, and later burrow to the surface making the tra- 
 ditional worm hole, as shown on Plate XX, b. From 20 to 30 days 
 are required for larval development, when the worms leave the 
 fruit usually before it falls, and seek a protected place to spin the 
 silken case or cocoon. Of those assuming this stage in mid- 
 
 Figure 9. The Plum Curculio. 
 
 summer, a portion transform the same season, while those going 
 into their cocoons late in summer or autumn do not emerge as 
 adults until the following season. There is usually one full genera- 
 tion, and a partial second each year in Connecticut. 
 
 The codling moth is usually less injurious in orchards which are 
 sprayed each year with arsenical poisons. 
 
 Plum Curculio: — The adult is a weevil or snout beetle which 
 hibernates in rubbish heaps, hedgerows, woodlands, et catera, 
 where it can find protection. It appears on trees soon after the 
 buds open, and soon after the fruit sets and the petals drop begins 
 to puncture the young fruit. Two kinds of punctures are made, 
 one for feeding and the other for depositing eggs. The latter are 
 crescent-shaped and the egg is placed just under the skin of the flap 
 on the concave side of the crescent. Egg-laying may extend 
 over nearly the whole season, though most of them are laid during 
 the first month after the blossoms fall. The feeding punctures 
 are small cavities eaten into the surface of the fruit and usually 
 occur in clusters. They may be made late in the season. There 
 is only one generation each year, and this insect usually breeds in 
 
PESTS OF FRUIT OF APPLE ORCHARDS. 219 
 
 stone fruits. The larvae do not develop in the apple, and the 
 only injury is that caused by the punctures. Plate XXI, c, shows 
 the egg-scars as they appear on the fruit at harvest time. The 
 application of poisons, though of some benefit, is not a satisfactory 
 control for this insect. Much more can be accomplished by 
 abolishing its hibernating places, like rubbish heaps, hedgerows, 
 et ccetera, in or near the orchard. 
 
 Other Chewing Insects: — Many insects might be included 
 under this head, but only a few will be mentioned in connection 
 with the orchards where our experiments were conducted. 
 
 Apple Maggot: — This was not a serious pest in these orchards, 
 though present and causing some injury on certain varieties. 
 Later treatments, so that the foliage and fruit will be coated with 
 poison during July, may be effective in poisoning the adults before 
 they lay eggs. 
 
 Leaf-Rollers: — In 1920, there was considerable surface injury 
 to fruit late in the season caused by the red banded leaf-roller 
 Eulia velutinana Walker, and the lesser apple worm Enarmonia 
 prunivora Walsh. Consequently some later treatments were 
 given a portion of some of the plots, but these insects were not 
 noticed in 1921, and the treatments gave no benefit. 
 
 Aphids: — The green apple aphid Aphis pomi DeGeer, and the 
 rosy aphid Anuraphis malifoliae Fitch (Aphis sorbi Kalt.) were 
 not prevalent in the experiment orchards in 192 1. Some eggs 
 hatched, but the aphids soon disappeared, perhaps on account of 
 cold storms, lady beetles, or other natural agencies, and caused no 
 appreciable injury. For this reason no marked benefit can be 
 shown by the treatment against these insects. The eggs hatch 
 at about the time that the leaf buds begin to unfold. Nicotine 
 sulphate in the delayed dormant, pink and calyx treatments should 
 control these aphids. 
 
 Red Bug: — The false apple red bug Lygidea mendax Reut. 
 was not abundant in any of the experiment orchards in 1921, but 
 was more prevalent in orchard No. ill than elsewhere. Here and 
 also in orchard No. II the check plots showed much more injury 
 than the treated pnes. The eggs hatch just before the blossoms 
 open and nicotine sulphate in the pink treatment and in the calyx 
 treatment, if thoroughly applied, should kill most of the nymphs. 
 
 Fungous Diseases. 
 
 Scab : — Scab was very prevalent during the past season in most 
 orchards. This can probably be accounted for in two ways ; first, 
 the mild winter, which allowed the fungus to carry over in good 
 condition on the old leaves and mature a large crop of spores 
 which infected the young foliage early in the spring, and second the 
 fact that there was a rainy spell which was most favorable for 
 
2 20 CONNECTICUT EXPERIMENT STATION BULLETIN 235. 
 
 scab infection and which prevented putting on the pink spray at 
 the proper time. Under Connecticut conditions the pink spray is 
 the important spray for scab control and on varieties which are 
 particularly susceptible it would seem desirable to put on two 
 sprays after the leaves come out and before the blossoms open. It 
 seems to be the consensus of opinion among plant pathologists 
 that it is not feasible to attempt to treat or destroy the leaves under 
 the trees, on which the scab carries over winter, but rather to 
 control it by proper and timely spraying. See Plate XXII, e. 
 
 Black Rot: — Black rot was more prevalent, especially on the 
 foliage, during 1921 than usual. This disease was present to a 
 greater or less extent in all the orchards which were observed dur- 
 ing the season and probably these represent a general condition 
 throughout the State. Usually Baldwin was the variety most 
 susceptible, although other varieties showed some infection. In 
 one orchard only was any serious damage done and in this only a 
 small number of trees were severely attacked. 
 
 Figure 10. Apple Scab. 
 
 On the leaf the black rot fungus makes small dark brown cir- 
 cular spots and later causes the leaf to turn yellow and drop pre- 
 maturely. This fungus also attacks the fruit, making a brown 
 rotting of the flesh of the apple, which form of infection was noted 
 in a few cases, but nowhere did any serious damage result. The 
 Hurlbut seemed to be more susceptible to fruit infection. 
 
 This fungus does not usually do any great amount of damage in 
 Connecticut and if present should be controlled by the ordinary 
 spraying schedule. The infection on the foliage evidently takes 
 place early in the season, making the pink spray important in its 
 control. This fungus is shown on the leaf on Plate XXI, e, and 
 on the fruit on Plate XXII, d. 
 
 Fruit Speck: — Fruit speck or "Brook's spot" is a fruit disease 
 and causes the very small irregular black spots on the skin of the 
 apple which on light skinned varieties are usually bordered with 
 red, the spots occurring most abundantly near the calyx end. 
 This disease should not be confused with "Baldwin spot" which 
 is a physiological trouble characterized by brown corky spots 
 
DUSTING AND SPRAYING OF PEACH ORCHARDS. 22 1 
 
 scattered through the tissue of the fruit. Fruit speck, being a 
 fungous disease, can be controlled by spraying with a fungicide 
 while the "Baldwin spot" is not affected by such applications. 
 To control fruit speck successfully, the spraying should be done 
 very thoroughly. The fruit speck fungus does not injure the 
 quality of the fruit but spoils its appearance, and makes an 
 entrance for various decay organisms. 
 
 Figure n. Sooty Blotch of Apple. 
 
 Sooty Blotch: — This disease is one of the most common apple 
 diseases and is probably one of the easiest to control by spraying, 
 yet it seems to be true that less attention is paid to it than to other 
 troubles, for instance, a grower will be much alarmed at a heavy 
 scab infection but will almost consider sooty blotch a necessary 
 adjunct to the finish of his fruit. The sooty blotch fungus grows 
 entirely on the skin of the apple and does no harm except to 
 injure its appearance seriously, as is shown on Plate XXII, f . 
 
 PEACHES. 
 
 In addition to the experiments with dusts and sprays in apple 
 orchards, experiments were conducted to test the comparative 
 values of dusting and spraying on peaches. Two orchards were 
 used, one at Mount Carmel owned by this Station, and the other 
 in Cheshire, owned by Mr. M. L. Coleman. 
 
 Apparatus and Materials Used. 
 
 In the spraying of both orchards, an Arlington X. L. power 
 sprayer with a ioo gallon tank was used, carrying two lines of 
 hose with one nozzle on each rod, at a pressure of about 125 
 pounds. The dusting machine used at Mount Carmel was a 
 Niagara duster, being the same one that was used in the apple 
 dusting experiments. The duster used at Cheshire belonged to 
 Mr. Coleman, and was also a Niagara machine. 
 
222 CONNECTICUT EXPERIMENT STATION BULLETIN 235. 
 
 The spray material used in both orchards was atomic sulphur, 
 at the rate of 10 pounds to 100 gallons of water. The dust used 
 at Mount Carmel was ordinary dusting sulphur, and at Cheshire 
 the dust used for the first two applications was a 70-20-10 mixture, 
 70 parts of sulphur, 20 parts of lime and 10 parts of lead arsenate. 
 For the third dusting at Cheshire, the lead arsenate and lime were 
 omitted. 
 
 Method of Recording Data. 
 
 In the peach experiments, the dropped fruit was not gathered 
 and scored as was the case with the apples. No count trees were 
 selected here, but a record taken from every tree which bore fruit. 
 In harvesting, several pickings were made and each fruit examined 
 and injuries recorded. This necessitated the examination of 
 120,063 individual fruits, or about 1,715 baskets. 
 
 » 
 
 Mount Carmel Orchard. 
 
 This orchard is ten years old, planted on the brow of a hill slop- 
 ing toward the west, and comprises 150 trees planted in five rows 
 of 30 trees each. The varieties which were used in this orchard 
 are Elberta, Carman, Champion, Mountain Rose and Greensboro. 
 The orchard was divided into three plots, the north plot was 
 sprayed, the south plot dusted and the center plot left untreated for 
 a check. 
 
 Three applications of spray and dust were made in this orchard, 
 the first on May 18th when the "shucks" had all dropped from 
 the young fruit; the second on June 16th and the last on July 13th 
 and 14th. The dust used was the regular dusting sulphur with 
 no lead arsenate or lime added. The liquid spray used was atomic 
 sulphur, 10 pounds to 100 gallons of water, with no lead arsenate. 
 As no arsenical poison was used in this orchard, and as there was 
 practically no scab, the only injuries recorded were those caused by 
 brown rot. 
 
DUSTING AND SPRAYING OF PEACH ORCHARDS. 223 
 
 RESULTS OF TREATMENT. 
 
 
 
 Good Fruit 
 
 Rot 
 
 
 
 Per Cent. 
 
 Per Cent 
 
 Elberta : 
 
 
 
 
 
 Spray- 
 
 98.6 
 
 1-34 
 
 
 Dust 
 
 99-6 
 
 .36 
 
 
 Check 
 
 99.6 
 
 .38 
 
 Carman: 
 
 
 
 
 
 Spray- 
 
 93- 
 
 7.2 
 
 
 Dust 
 
 97-5 
 
 2-5 
 
 
 Check 
 
 No Checks for this variety 
 
 Champion : 
 
 
 
 
 
 Spray 
 
 89-3 
 
 10.7 
 
 
 Dust 
 
 98.4 
 
 1.6 
 
 
 Check 
 
 96.5 
 
 34 
 
 Mt. Rose : 
 
 
 
 
 
 Spray 
 
 88.2 
 
 1 1.8 
 
 
 Dust 
 
 99.2 
 
 .88 
 
 
 Check 
 
 98.5' 
 
 1.6 
 
 Greensboro : 
 
 
 
 
 
 Spray 
 
 79-9 
 
 20.1 
 
 
 Dust 
 
 87.5 
 
 12.7 
 
 
 Check 
 
 No Checks for this 
 
 variety 
 
 Discussion of Results. 
 
 On all varieties the dust was more effective in controlling brown 
 rot than the spray. The amount of scab and curculio injury was 
 so slight that no data was taken. The check trees in this orchard 
 had better fruit than the sprayed trees because the trees were close 
 together and the check trees were north of the dusted plot and at 
 every application of dust the wind was from the south or south- 
 west, thus blowing the dust onto the check trees. 
 
 Cheshire Orchard. 
 
 This orchard is about the same age as the Mount Carmel peach 
 orchard. Because of the size of the orchard, only a portion con- 
 taining two varieties, Carman and Elberta, was used in the spray- 
 ing and dusting tests. Mr. Coleman, the owner of the orchard, 
 has been dusting peaches for several years with satisfactory 
 results, and this year he dusted all of his orchard except that por- 
 tion where the sprayed plot was located. The records of the dust- 
 ing were taken from a portion of the orchard adjacent to the 
 sprayed plot. A few trees on the edge of the orchard at the end 
 of the sprayed plot were left without treatment as checks. One 
 hundred and thirteen trees were included in the three plots. 
 
 This peach orchard, like the other, was given three treatments 
 of spray and dust, on the following dates : May 22, June 18 and 
 July 13. The spray used was atomic sulphur, 10 pounds to 100 
 gallons of water. No lead arsenate was used in the liquid spray. 
 
224 CONNECTICUT EXPERIMENT STATION BULLETIN 235. 
 
 The liquid spray was applied with the same outfit as was used 
 at Mount Carmel. The outfit was carried to Cheshire on a Ford 
 truck to save time. On arriving at Cheshire the sprayer was 
 unloaded and a horse used to draw it about the orchard, as the 
 trees were too close to allow the truck to pass through the orchard. 
 Five pickings were made of Carman, August 10, 12, 14, 16 and 
 19, and four of Elberta, September 2, 5, 7 and 9. There was con- 
 siderable, scab in this orchard, so records were made of light and 
 heavy infestations of scab, together with rot and curculio. 
 
 RESULTS OF TREATMENT. 
 
 Elberta : 
 
 Carman : 
 
 
 Good 
 Per Cent. 
 
 Rot 
 Per Cent. 
 
 Light Scab 
 Per Cent. 
 
 Heavy Scab Curculi 
 Per Cent. Per Cem 
 
 Spray 
 
 Dust 
 
 Check 
 
 65- 
 
 69.9 
 
 174 
 
 2.66 
 5-24 
 5.8l 
 
 27-39 
 22.4 
 
 58.4 
 
 1.2 S.52 
 
 •94 3-24 
 17.6 2.91 
 
 Spray 
 
 Dust 
 
 Check 
 
 37-4 
 
 56/ 
 
 27-3 
 
 7.15 
 492 
 16.5 
 
 43-2 
 27.4 
 38.2 
 
 12.12 4.61 
 
 9-4 5-12 
 21.7 4-53 
 
 It will be noted that on both varieties the dust gave a higher 
 percentage of good fruit than the spray, largely through the more 
 effective control of rot and scab. The lead arsenate in the dust 
 did not control curculio to any appreciable extent. For some 
 unknown reason the curculio injury was less in the check plot in 
 both varieties than in either the dusted or sprayed plot. Peaches 
 scored as "light scab" had only a small amount of scab, and would 
 be graded as No. I. Those scored "heavy scab" would not be 
 included in a No. I grade. Most of the peaches in the curculio 
 column would undoubtedly be included in a No. I grade. 
 
 Cost of Dusting and Spraying Peach Orchards. 
 
 The price of dusting sulphur without lead arsenate used for 
 dusting the peach orchards was $3.75 per 100 pounds in 1921, and 
 the cost of atomic sulphur in 100 pound lots was $12.75. Allow- 
 ing one pound of dust and one gallon of spray per tree the cost is, 
 dust 324 cents per tree, spray 1%. cents per tree for one treat- 
 ment only. There would be quite a saving of time in favor of the 
 dust which would partly offset the higher cost of material and 
 make the treatments more nearly equal in price. However, it is 
 doubtful if it would pay to dust peaches unless a large acreage was 
 to be treated so that enough time could be saved to make an appre- 
 ciable cut in the labor cost. It would be necessary to have a spray 
 outfit for the dormant treatment and the extra cost of the duster 
 would probably not be offset by the saving of time and slightly 
 better results on a small orchard. 
 
PESTS OF THE FRUIT OF PEACH ORCHARDS. 225 
 
 Pests of the Fruit of Peach Orchards. 
 
 insects. 
 
 Plum Curculio: — The curculio is unquestionably the most 
 important insect attacking the fruit of the peach. This insect has 
 already been discussed on page 218 as an apple pest. In the 
 peach fruit, the larvae develop to maturity and transform. Most 
 of the infested fruits drop early and therefore do not show at 
 harvest time, though the egg-laying and feeding punctures are 
 often apparent. Curculio can best be controlled by getting rid of 
 all hibernating places near the orchard. Arsenical applications, 
 though a help, should not be depended upon as the only means of 
 control. 
 
 FUNGOUS DISEASES.- 
 
 Brown Rot: — Brown rot is the most serious fungous disease 
 that the peach grower has to contend with, but it can be controlled 
 by thorough and timely treatment. Usually this is a disease of 
 the fruit but under favorable conditions such as obtained in the 
 spring of 1921, serious infection of the blossoms on early varieties 
 is likely to take place. Such infection not only kills the blossom 
 but forms a canker which often girdles and kills the entire branch. 
 
 The blossom and twig infection seems to be worst in orchards 
 where spraying or dusting has not been regularly practiced, and 
 there are large quantities of mummied fruits on the ground and 
 in the trees to spread the disease early in the season. 
 
 Peach Scab: — Peach scab does the larger part of its damage 
 on the fruit, but the fungus infects the twigs and leaves as well. 
 It is from the twigs that the scab fungus is spread to the fruit by 
 the spores falling and being washed onto them by rain. In this 
 connection it is interesting to note that scab spots are always on 
 the upper surface of the fruit. Like many fungous diseases an 
 important factor in scab control is to prevent it from getting a 
 start in the orchard. If an orchard is well sprayed or dusted 
 from the start, scab probably will not be especially abundant. 
 
2 26 connecticut experiment station bulletin 235. 
 
 Summary. 
 
 1. Dusting experiments in comparison with spraying" were con- 
 
 ducted in Connecticut in 1921 in four apple orchards con- 
 taining 757 trees, and in two peach orchards containing 263 
 trees. This involved the scoring of 150,296 apples, equiva- 
 lent to about 334 barrels, and 120,063 peaches, or about 
 1,715 baskets. 
 
 2. The dusts were all applied with Niagara dusting machines, 
 
 and the sprays with Friend and Arlington X. L. power 
 sprayers. In each case two treatments were given after 
 blossoming on apples, and three treatments on peaches. 
 
 3. The dusts used in the apple orchards were the sulphur-lead 
 
 dust, sulphur-lead-nicotine dust, and Sanders' dust. The 
 liquid spray used for comparison in all apple orchards con- 
 tained liquid lime-sulphur, lead arsenate and nicotine sul- 
 phate. In one orchard comparative tests were made 
 between liquid lime-sulphur, dry lime-sulphur, B. T. S., and 
 Bordeaux mixture, with lead arsenate added to each. 
 
 4. In nearly all cases the best apples were obtained from the 
 
 sprayed plots. Both spray and dust gave fairly good con- 
 trol as regards codling moth, and other chewing insects ; 
 neither controlled curculio ; the spray was more effective in 
 controlling the fungous diseases. In the sprayed orchard 
 dry lime-sulphur gave a larger percentage of good fruit 
 than liquid lime-sulphur, B. T. S., or Bordeaux mixture. 
 
 5. The chief pests attacking the fruit in these apple orchards in 
 
 1 92 1 were codling moth, plum curculio, apple maggot, 
 various chewing insects, aphids, red bug, scab, black rot, 
 fruit speck and sooty blotch. 
 
 6. On peaches the only spray was atomic sulphur, and the dusts 
 
 were sulphur, and sulphur-lime-lead arsenate dust. 
 
 7. In all the peach orchards the dusted plots gave slightly better 
 
 fruit than the sprayed plots. Peach scab and brown rot 
 were controlled by both dust and spray. 
 
 8. The chief pests attacking the fruit in these peach orchards in 
 
 1 92 1 were curculio, brown rot and peach scab. 
 
 9. At present dusting is more costly than spraying in both peach 
 
 and apple orchards. 
 
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