SPRAYING AGAINST GRAPE LEAFHOPPER. 5 



for the past 10 years, however, have averaged about 13 cents per 

 basket. On this basis the cash increase on the treatment in 1910 

 was $20.93 per acre, and on the treatment for the second season of 

 1911 the increase was $69.42 over that of 1909 before any spray 

 treatment was made against this pest. 



The actual cash receipts for the three seasons were as follows: 



1909 Unsprayed, 11 cents per basket, 262 baskets, $28.82 per acre. 



1910 Sprayed, 19 cents per basket, 423 baskets, $80.37 per acre. 



1911 Sprayed, 10 cents per basket, 796 baskets, $79.60 per acre. 



Since the actual prices in 1909 and 1911 are almost uniform, the 

 increase in cash return as a result of increased yield is readily seen. 

 This increased cash return in 1911 was $50.78 per acre. 



During these three seasons the general treatment for the vineyard 

 has been the same for each season. The soil was cultivated several 

 times and 420 pounds of fertilizer containing 5 per cent nitrogen, 8 per 

 cent phosphoric acid, and 8 per cent potash were applied each season. 

 A Bordeaux and arsenate of lead spray application, consisting of 4 

 pounds of copper sulphate, 5 pounds lime, and 3 pounds arsenate of 

 lead to 50 gallons of water, was made just after blossoming. A later 

 application of 1 pound of copper sulphate to 100 gallons of water 

 was made for protection against mildew. Thus the general treat- 

 ment of the vineyard was good and conducive to the securing of 

 maximum results. 



The additional cost of material and labor involved in making the 

 spray application against the grape leafhopper was as follows : 



Cost of team per day $2. 25 



Boy to drive 1. 00 



Man to handle nozzle 1. 75 



Tobacco extract No. I (strength 3 quarts to 100 gallons of water, applied 175 



gallons per acre) per gallon. . . 85 



Cost of material for 3 acres 3. 36 



Total cost of spraying 3 acres per day 8. 36 



Total cost of spraying 1 acre 2. 79 



The power was supplied by a tractor sprayer. 



There is no doubt that this tobacco-extract application during the 

 past two seasons has effectively controlled the grape leafhopper and 

 is largely responsible for the increase in crop yield and for the vig- 

 orous growth of vine in this vineyard. 



EXPERIMENT IN VINEYARD OF MR. W. E. GRAY, NORTH EAST, PA. 



The vines in the vineyard of Mr. W. E. Gray, North East, Pa., 

 were badly infested by grape leaf hoppers. They were five years old 

 and were bearing a heavy crop of fruit. No spray treatment was 

 given them except with tobacco extract No. I for this pest. About 



40814°— Bull. 116, pt. 1—12 2 



