60 



DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



VINEYARD EXPERIMENTS WITH POISON SPRAYS IN 1909. 



The spray work for 1909 was conducted in the same vineyard as in 

 1907 and 1908. The plat arrangement was the same as in 1908. The 

 unsprayed check vines were also in the same location as in 1908. 

 (See fig. 21.) The same gasoline-engine spraying outfit was used as 

 in the two previous seasons and the nozzle arrangement was also the 

 same. A pressure of from 100 to 125 pounds was maintained and 

 about 100 gallons of spray were applied per acre. The first applica- 

 tion was made on Plats I and II June 8, just before the blossom buds 

 opened. The second application was made June 28, after blossoming, 

 when the berries were about the size of buckshot. At this date all 

 four plats were sprayed. Plat II was given a double spraying on 

 this date. The other plats received only one application at each date 

 throughout the season. All four plats were sprayed July 9, when the 

 berries were large enough to touch each other in the cluster. (See 

 Table XXVII, showing spray formula and number of applications.) 



Table XXVII. — Spray formula and dates of applications against larvse of the grape- 

 berry moth. Vineyard of Mr. W. S. Wheeler, North East, Pa., 1909. 



Plat No. 



Spray formula. 



Number 

 of spray 

 applica- 

 tions. 



Date of application. 



II 



Ill 



IV 



Va,- Vb. 



Three pounds arsenate of lead to 50 gallons of Bordeaux 

 mixture. 



...do 



....do 



...do 



Unsprayed 



June 8, 28; July 9. 



Do. 

 June 28; July 9. 

 Do. 



Counts of infested berries were made on 25 vines in each of the 

 unsprayed check plats and also in each of the sprayed plats. (See 

 Table XXVIII, showing progress of infestation for season of 1909.) 



Table XXVIII. — Progress of infestation of fruit by larvse of the grape-berry moth in 

 experimental plats. Vineyard of Mr. W. S. Wheeler, North East, Pa., 1909. 



FIRST COUNT OF INFESTED BERRIES, MADE ON JULY 25. 



Plat No. 



Date of spray application. 



Spray formula. 



Number 

 of appli- 

 cations. 



Number 

 of vines 

 exam- 

 ined. 



Number 



of infested 



berries. 



I 



June 8, 28, July 9. 



5-5-3-50. 



3 

 3 



2 

 2 



25 

 25 

 25 

 25 



23 



II 



do... 



5-5-3-50 



14 



Ill 



June 28, July 9 



5-5-3-50 



17 



IV 



do 



5-5-3-50. 



12 











SECOND COUNT OF INFESTED BERRIES, MADE ON SEPTEMBER 21 TO 24. 



I 



June 8, 28, July 9 



do... 



5-5-3-50 



3 

 3 

 2 

 2 



25 

 25 

 25 

 25 



750 



II 



5-5-3-50 



396 



Ill 



June 28, July 9 



5-5-3-50 



550 



IV 



do 



5-5-3-50 



390 











