ONE-SPKAY METHOD FOE CODLING MOTH. ETC. 



145 



The plum curculio, it will also be noted, was not especially destruc- 

 tive at Saugatuck, Mich., during the season of 1909, the unsprayed 

 trees showing 87.42 per cent of fruit free from injury. Nevertheless 

 the demonstration and one-spray plats show a fair benefit, but the 

 difference in the amount of fruit free from injury between these two 

 plats, namely, 1.23 per cent, is not important. 



SUMMARY STATEMENT OF RESULTS. 



For the purpose of more ready comparison, the percentages of fruit 

 free from codling-moth and plum-curculio injury on the one-spray, 

 demonstration, and unsprayed plats, from the several localities, are 

 tabulated in Table XXIV. The average percentage of fruit free from 

 these insects for the four orchards gives for the one-spray method 

 91.46 per cent as against 96.57 per cent for the demonstration treat- 

 ment, a gain in favor of the latter of 5.1 1 per cent. Comparing the final 

 average of percentage of fruit free from the plum curculio, there is seen 

 to be a gain in favor of the demonstration treatment of 6.27 per cent. 



Table XXIV. — Percentages of fruit free from injury by the codling moth and plum cur- 

 culio on one-spray, demonstration, and unsprayed plats in Arkansas, Virginia, and 

 Michigan, in 1909. 



Locality. 



Codling moth. 



Plum curculio. 



One 

 spray. 



Demon- 

 stration. 



Un- 

 sprayed. 



One 



spray. 



Demon- 

 stration. 



Un- 

 sprayed. 



Siloam Springs, Ark 



92.76 

 84.07 

 91.68 

 93.61 



98.12 

 94.13 

 92.74 

 97.66 



66.74 

 53.02 

 54.00 

 77.79 



86.34 

 73.93 

 57.90 

 97.54 



82.88 

 86.89 

 40.82 

 98.77 



8.85 





54.02 



Mount Jackson, Va 



27.23 





87.42 







Average of four localities 



91.46 



96.57 



65.14 



77.10 



83.37 



49.17 







Table XXV presents in comparison the effect of treatments for the 

 four orchards in reducing the number of wormy apples. The table 

 shows, besides the total efficiency, the protection afforded to each 

 of the different parts of the apple. From the averages of the four 

 localities it will be seen that approximately two-thirds of the total 

 larvae on the unsprayed plat entered through the calyx, while on 

 the sprayed plats over three-fourths of the worms entered the fruit 

 by way of the side. This shows the very much greater efficiency 

 of the poison in the calyx than of that on the side of the fruit and 

 emphasizes the twofold advantage of a thorough poisoning of the 

 calyx, as there it is that the spray gives the greatest protection 

 against the greatest number of larvae. A comparison of the effects 

 of the one-spray and demonstration treatments on the percentage 

 of apples wormy at the calyx shows about an equal degree of pro- 

 tection by the two methods, the average for the demonstration 

 treatment being slightly the better. As to side entrance, the one- 

 spray gave little improvement over the unsprayed condition, while 

 the demonstration showed a considerable reduction. Both methods 

 were effective in reducing entrance at the stem end, the demonstra- 

 tion somewhat the more so. 



