4 MAINE AGRICUI,TURAL EXPERIMENT STATION. I914. 



6 rows each, or 36 trees. The unsprayed check, the bordeaux 

 plot, the arsenite of zinc plot and those upon whidh insecticides 

 were used alone consisted of 3 rows each, or 18 trees. 



All plots received the same nurrcber of sprayings on the same 

 dates with the exception of plot 4. On this the first application 

 of lime-sulphur was omitted for comparison with plot 3 to 

 test the efficiency in control of apple scab of the application 

 usually made when the blossom buds are showing pink. All 

 spray materials were applied with a gasoline power spraying 

 outfit at a pressure of from 125 to 150 pounds. The tank, pump 

 and hose were thoroughly washed out with water after each 

 separate spray material was used. The original plan was to 

 spray all plots with the exception of number 4 when the blos- 

 som buds were showing pink, repeat the application for all, 

 number 4 included, just after the petals fell and again about 

 2 weeks later. This program was adhered to except that be- 

 tween the second and third sprayings a period of 21 days 

 elapsed. 



Weather conditions during the early part of the season 

 materially influenced the date of application of the different 

 sprays. The latter part of April and the first week of May 

 were abnormally warm and very little rain fell. As a result 

 the blossom buds came along very rapidly so that they were 

 in condition such that it was necessary to make the first appli- 

 cation on May 8. This was immediately followed by a month 

 of unseasonably cold weather with frosts and cold, northwest 

 winds associated with continued cloudy weather and heavy 

 rainfall. The flower buds opened very slowly and the petals- 

 did not drop so that the second application cojuld be made till 

 June 3. This allowed an interval of 26 days between the first 

 and second applications as compared with only 12 in 1912. The 

 third and last application was made on June 24. 



In 1913 dry, powdered arsenate of lead, using half the quan- 

 tity by weig*ht as compared with the paste form previously 

 employed, was adopted for use on all the orchards on the farm. 

 On all the experimental plots sprayed with a fungicide, (not 

 counting plot 10 where arsenite of zinc was used) one pound 

 of this dry arsenate of lead was added as an insecticide to each 

 50 gallons of spray. With this exception the treatment of each 

 plot is given below. 



