76 



DECIDUOUS FltUIT INSECTS AND INSECTICIDES. 



June 14, July 25-26, and August 15. The table below shows the 

 results, as determined from 5 sprayed and 5 unsprayed trees in each 

 plat : 



Table V. — Comparison of sound and worviy fruit frovi 5 sprayed and 5 unsprayed trees, 

 Ben Davis variety, Roudebush Orchard, Owensville, Ohio, 1907. 



Diiti' of spraying iind 

 luiinhcr of trees. 



Sprayed May 10, June 

 14, July 25, and 

 August 15: Trees 1 

 to 5 combined 



Unsprayed; Checks A 

 to E combined 



Total 

 crop. 



Windfalls. 



Bushels. 

 9.80 



No. 



78 



1,992 



No. 

 1,997 



2,218 



No. 

 2,075 



4,210 



Fruit from tree. 



No. 

 121 



No. 

 1,571 



No. 

 1,692 



No. 

 199 



2,643 



No. 

 3,568 



2,286 



No. 



3,767 



4,929 



a. 3 



=^1 



94. 72 

 46. 38 



The tabulated results show that the four applications gave about 

 94 per cent fruit free from codling moth injury and trebled the yield 

 in bushels, while the total marketable crop in bushels was more than 

 twice doubled. In the checks the percentage of wormy fruit in the 

 total yield was 46.38 per cent, whereas in the sprayed trees it was 

 but 5.28 per cent. The contrast between the treated and untreated 

 trees at harvest time was marked, even to the casual eye, because the 

 latter had been partly defoliated by various leaf-feeding insects, 

 and the attack of the codling moth and plum curculio had been dis- 

 astrous to the fruit yet remaining; whereas the foliage and fruit of 

 treated trees were in almost perfect condition. The four treatments 

 also prevented over 50 per cent of the injury of the plum curculio, 

 which is a more serious enemy of apples in this vicinity than is the 

 codling moth. 



The four applications re((uired 450 gallons of the mixture at a cost 

 of $0,016 i)or gallon, a total cost of $7.20 for the Bordeaux mixture 

 and poison. Adding the cost of labor for 2 men at $1 .50 per day and a 

 team at $2 per day for one and one-half days, which is $7.50, the cost of 

 the whole operation was $14.70, or at the rate of $0.54 per tree. Placing 

 the price of apples per bushel at $1, the net returns from a single 

 unsprayed tree would be about 36 cents, whereas the net returns from 

 a single .sprayed tree would be $1.31, a net gain of al)out 95 cents 

 per tree. As will be seen from the table, the crop in this orchard was 

 ({uite light. With a normal crop the percentage of benefit would 

 have been much larger. 



