8 DECIDUOUS FRUIT INSECTS AXD INSECTICIDES. 



acre was sprayed. The work was done with a tractor vineyard 

 sprayer. This machine had been in use several seasons and was not 

 working at its best. The spray was applied by the "trailer" method. 

 Owing to the poor working of the pump a high pressure was not 

 maintained. The pressure varied anywhere from 150 pounds to 50 

 pounds. Most of the time it ran below 80 pounds. For this reason 

 it was thought necessary by Mr. Bostwick to make the application on 

 both sides of the trellis. In spite of these drawbacks good results 

 were secured. About 275 gallons of liquid were applied per acre. 

 This is more liquid than would have been applied by this machine 

 had it been in good working condition and, in addition, more time 

 was consumed in making the application on both sides of the row. 

 About 600 gallons of spray were applied per day covering about 2} 

 acres. Tobacco extract Xo. II was used at a dilution of 1 to 1,300 

 parts of water. 



Labor cost of application per acre $2. 75 



Tobacco extract Xo. II — 1 to 1, 300 parts water, per acre 2. 58 



Total cost of labor and material per acre 5. 33 



The net yield of grapes from the three plats was as follows: 



One acre of vines east of unsprayed plat 8,462 pounds grapes 



One acre of vines west of unsprayed plat 8.327 pounds grapes 



One acre of vines, unsprayed plat 7,153 pounds grapes 



The cash value of the fruit was $25 per ton, or $0.0125 per pound. 



Cash value of yield on 1 acre east of check 8105. 77 



Cash value of yield on 1 acre west of check 104. 09 



Cash value of yield on 1 acre unsprayed 89. 41 



Increased yield on west plat per acre over check was 1,309 pounds, or 16. 36 



Increased yield on west plat per acre over check was 1,174 pounds, or 14. 07 



Xet cash gain on sprayed plats after deducting cost of labor and 

 material : 



Gross gain on plat west of check per acre $16. 36 



Total cost of labor and material per acre 5. 33 



JNet gain resulting from spraying per acre 11. 03 



Gross gain on plat east of check per acre 14. 67 



Total cost of labor and material per acre 5. 33 



Net cash gain resulting from spraying per acre 9. 34 



In addition to this increase in weight of fruit yield it was observed 

 that the berries of the grapes were much larger and of better color 

 than was the fruit on the unsprayed vines. It was also observed that 

 the fruit from the sprayed vines gave a greater weight per basket. 



507 baskets from the west plat averaged 20.7 pounds per basket. 

 497 baskets from the east plat averaged 20.7 pounds per basket. 

 478 baskets from the unsprayed plat averaged 19 pounds per basket. 



