19 



SUMMARY. 



In considering the final results of this experiment,, several impor- 

 tant facts should be "borne in mind : 



First. The orchard had never before been systematically treated, and only a 

 partial effort had been made to control this insect. 



Second. The crop was very small, thus giving the fruit very little opportunity 

 to escape attack. The same conditions as to the crop prevailed in an adjoining 

 orchard and although systematic spraying was applied, as has been the case for 

 several years, the number of wormy apples was unusually large. 



Third. The weather late in May and early in June was very wet, and this may 

 have caused the second spraying to have done a minimum amount of good. 



Fourth. In the light of the results which show a very large amount of damage 

 by the second brood of moths, it raay be that more effective work would have been 

 accomplished if the third spraying had baen made a week earlier in July. 



July 13, the date on which the spraying was made, is about as early as it is usual 

 in this latitude to apply the third spraying. According to Riley, the second brood 

 of the moth emerges in the latitude of St. Louis about July 8. As Delaware is 

 about 125 miles north of that latitude, an application of poison on the 13th should 

 be in sufficient season to protect the fruit from this brood. Unfortunately I was 

 unable to determine the exact date of emergence of the second brood, but I am 

 informed by Mr. Lowell Roudebush, one of the progressive horticulturists of 

 Clermont County, which is in the southern part of the State, that he observed 

 specimens of the second brood in his orchard at Nicholsville on July 7, 1902, and 

 on July 12, 1903. 



The materials used by us were of known strength, but the arsenate of lead« 

 applied by Mr. Hudson depended on the purity of the raw materials that were 

 obtained. This will always be the case with homemade preparations unless a 

 definite guaranty of the chemical purity ,of the ingredients is required. 



COMPARISON OF RESULTS. 



It will be observed that on the check row 46 per cent of the fruit 

 was ruined by the first brood and 47 per cent by the second brood of 

 the codling moth. The remaining 7 per cent amounted to about 2 

 bushels and was small and imperfect. Had no spraying been done in 

 this orchard scarcely any marketable fruit would have been harvested. 



A comparison of the percentages of perfect fruit on the rows which 

 were treated three times and those that were treated twice shows a 

 slight increase in favor of three treatments. In this experiment the 

 difference is not marked enough to warrant the expense of an addi- 

 tional treatment. The prevailing wet weather immediately following 

 May 22 inay have been responsible for this state of affairs. 



It will be noted that the per cent of wormj^ fruit was considerabty 

 greater in each case where Bordeaux mixture was added. The results 



« An analysis of the acetate of lead and arsenate of soda used by Mr. Hudson, 

 and also by the owner of the adjoining orchard, Mr. Vergon, in preparing this 

 material, was made by the official chemist of the Ohio State board of agriculture. 

 His report, which was received since the presentation of this paper, states that 

 the arsenate of soda contained 25.9 per cent of salt; hence it was very impure. 



