148 



the higher percentage being obtained on the plot receiving 

 three applications. In a like manner the three treated with 

 a Bordeaux nozzle yielded 98.55 to 99 per cent, worm-free 

 fruit, a slightly higher percentage, as in the preceding 

 group, being obtained on the plot receiving three applica- 

 tions. This apparent lack of material benefit resulting 

 from the second and third treatments, may be due in slight 

 measure to the fact that the plots sprayed but one produced 

 more apples than those receiving the second and third 

 sprayings, though the difference is not uniform, and the 

 variations between the percentages of worm-free fruit do 

 not coincide exactly with the difference in yield between 

 the various plots. For example, between plots 2 and 3 there 

 is a difference of only 636 apples out of approximately 10,- 

 000, a variation hardly large enough to materially influence 

 the percentage of worm-free fruit. This latter is only .06 

 per cent, in favor of the trees receiving three applications. 

 Similarly, on plots 4 and 5 there is a variation of but 1,030 

 out of approximately 10,000, and a difference in the per- 

 centage of worm-free fruit, of but .46 per cent, in favor of 

 the trees sprayed twice. 



A comparison of the fruit on the maximum and mini- 

 mum trees, shows that in plot one the maximum tree, pro- 

 ducing 8,745 apples, yielded but .63 per cent, wormy fruit, 

 while the minimum tree, producing 2,507 apples, had 3.16 

 per cent. Similar results were obtained in other plots. 

 That these variations are mostly local and hardly of general 

 application, is shown by a study of all the plots. There 

 was, as pointed out previously, a remarkably uniform per- 

 centage of worm-free fruit throughout, despite the consid- 

 erable variation in product. The benefit resulting from one 

 or more thorough applications is shown by comparing the 

 percentage of worm-free fruit, 98.55 to 99 per cent, on the 

 sprayed trees, with that obtained on the two check trees, 

 namely, 72,73 per cent. It is thus seen that approximately 

 25 per cent, or a little more of the fruit may be protected 

 from codling moth injury by one application. The benefits 

 of the second or third application must of necessity be re- 

 stricted to reducing the infestation in the 1 or 1.5 per cent, 

 of wormy fruit remaining. 



The study of the wormy fruit gives some interesting 

 data as to the point of attack, though very little can be 

 g^leaned therefrom in favor of using a coarse spray with a 



