December, 1909.] 



THE CODLING MOTH. 



79 



crop of fruit on any tree, 4.7 per cent, drops as wormy and 4.1 

 per cent, is wormy picked. 



Subtraetino- tlic ]Kn-eentage which drops plus the percentage 

 which is wormy when picked from 100, gives the percentage of 

 the total crop which is picked free from worms, which is the 

 essential matter for the fruit grower. On the unsprayed plots 

 the picked fruit free from worms is found to average only 43 

 per cent, of the total crop, while on all the sprayed plots it 

 averages 70 per cent., a difference of 27 per cent., of the total 

 crop. Thus a gain of about one-fourth of the crop seems to be 

 a fair average of the actual benefit to be derived from spraying, 

 if we base our estimates upon the total fruit borne by the tree. 

 This would mean that on a sprayed tree which picked three bar- 



NOT SPRAYED 



SPRAYED 



15% 

 WORMY 



45 7» 



NOT WORMY 



, I.7BBLS 



NET VALUt 



$ 1.70 



5 7o 

 WORMY 



Z 7% WORMY NOT WOl^MY 15 7o 



' ^Ji^Vp^" 2.BBBLS 

 \f PV^°*^^ VALUE 



$2.80 



6%V0RHY' " MtfT WORimaTo 



DROPPED 42«^o DROPPED 2S'7. 



Fig. 11.— Average results of spraying in nine New Hanip-shiru orchards in 1906, 1907 

 and 1908, showing the proportion of fruit which drops and is picked and the propor- 

 tion which is wormy and free from worms on sprayed and unsprayed trees. The 

 protlt shown i.s based on a crop of three barrels picked fruit on the sprayed trees. 



rels of fruit, one barrel of perfect fruit, worth $1 to $1.25 net, 

 had been gained by the spraying. 



If the difference in amount of perfect picked fruit was based 

 on the picked fruit only, leaving the drops out of consideration, 

 the benefit would appear to be only about three-fourths of that 

 shown above, but only by taking the dropped fruit into account 

 can a correct estimate of the value of the spraying be made. 

 "When there is an unusual amount of worminess and the best 

 spraying, the benefit due to spraying will often amount to half 

 of the total fruit borne by the tree, as was shown by some of 

 our plots, which in the case of a tree with the same amount of 

 fruit as cited above, would amount to two barrels instead of one 



