ANNUAL REPORT, 1935 



45 



Percent- Percentage of Fruit Showing 

 age of Injury from — 



Variety Material Clean 



Fruit Curculio Codling Scab 



Moth 



Mcintosh Special lead arsenate 91 1.7 1.8 Trace 



Standard lead arsenate 84 . 3 1.4 1.4 10 . 6 



Ben Davis Special lead arsenate 90 5.5 2.1 



Standard lead arsenate 80.0 13.6 3.2 



R. I. Greening ..Special lead arsenate 93.5 0.7 3.5 



Standard lead arsenate 93 . 2 2.9 1 Trace 



Considerable russeting was noted in Ben Davis fruit sprayed with the stan- 

 dard lead arsenate. The object of such improvement in lead arsenate would be 

 a greater control of codling moth in the early sprays, giving the main emphasis 

 in the late applications upon apple maggot, which has been shown to be con- 

 trollable by a weaker dosage of the arsenical or by dust applications. 



Apple Maggot Control. (A. I. Bourne. ) The adult flies were on the whole 

 less abundant than normal and appeared 7 to 10 days later than usual. In 

 most orchards the pest was much less prevalent than in former seasons except 

 where treated orchards were in close proximity to neglected trees. In the areas 

 under observation, the benefit from the removal of neglected trees in 1933 was 

 becoming obvious, and control of the pest was much less difficult. The whole- 

 sale removal of neglected trees created a serious problem for the year following 

 their destruction. Fruit from such trees had been in most cases badly riddled 

 by maggot the previous summer and this led to the appearance of thousands of 

 flies which migrated to the nearest trees, usually commercial orchards. It was 

 particularly essential, therefore, that a thorough control program be followed 

 to give protection against this heavy infestation, and it was noted that where a 

 complete spray program was followed in 1934 the problem of control was much 

 simpler in 1935. In general, except where orchards were inadequately sprayed 

 in 1934 or where the problem was complicated by neglected trees still remaining 

 adjacent to orchards, the recommended spray program gave satisfactory control. 



Additional data on the influence of soil conditions and of exposure upon the 

 appearance of flies were secured by Professor Whitcomb at Waltham. These 

 are as follows: 



Date of Emergence of Apple Maggot Flies, Waltham 



In Sun In Shade 



Cultivated 



1st fly June 26 



25% flies July 16 



50% flies July 18 



75% flies July 21 



1st fly July 4 



25% flies July 17 



50% flies July 20 



75% flies July 25 



