126 REPORT OF STATE BOARD OF HORTICULTURE. 



Most failures to achieve good results are reported in spray- 

 ing for codling moth. In speaking about this to Mr. Olwell 

 of Central Point, who is now most successful in spraying, he 

 tells me, and which is confirmed by my own observations, that 

 the largest percentage of failures is attributable to the settling 

 of the poisons used in the spray tank or barrel, or in other 

 words, the agitator or paddle is not sufficiently used to keep 

 the poisons thoroughly mixed, so the last few trees sprayed 

 out of each barrelful get an overdose, and the rest none. An- 

 other reason for the failures is that the spraying is not done 

 often enough, nor late enough in the fall. Six times during 

 the season, or at least every three weeks, is none too often. 

 Prof. E. A. Popenoe, of the Kansas Experiment Station, says, 

 in this connection : • 



CAUSES OF FAILURE IN SPRAYING. 



i I 



A belief exists in the minds of some fruitgrowers that 

 recommended metliods for the destruction of the codling 

 moth are worthless ; that spraying with arsenic compounds 

 has proven of no avail. Disregarding the opposition of some 

 whose ill-cliosen statements furnish their own refutation, we 

 must still admit that trials of spraying methods by our fruit- 

 growers have too often resulted in apparent failure, and, in 

 consequence, have measurably destroyed confidence in these 

 methods. 



"These reported failures may have come from one of 

 several causes : First, an exaggerated idea of the results to 

 be obtained by spraying has led to anticipations of a degree 

 of success not warranted b}^ the experience of the most suc- 

 cessful experimenters ; second, proper spraying demands 

 such close adherence to several indispensable points of prac- 

 tice that even careful men may fail through oversight of 

 these particulars ; or, finally, the adverse report is made 

 without the just estimate of the result of the experiment; 

 for it will be granted that a true judgment of the degree of 

 success can only be had by the comparison of trees treated 

 with trees untreated in the same surroundings, and this com- 

 parison lacking, the estimate of success or failure is alto- 

 gether a matter of opinion, and not to be admitted as evi- 

 dence. 



"As to the first : No one qualified to advise in the matter 

 will claim that a single season's trial of spraying against the 

 codling moth can alone bring perfect success, especially 



