64 MASS. EXPERIAfENT STATION Bl'LLETTN 37?- 



Studies of the value of fixed nicotine in late-season applications for 

 codling moth control, as a supplement to the present spray schedule, were 

 continued in the same commercial orchard as in 1939. Codling moth was 

 reduced to such low proportions in 1939 that banding was discontinued 

 in 1940. Two applications of fixed nicotine were made in addition to the 

 regular schedule: the first in late July in substitution for the regular 4th 

 cover spray, and the second in mid-August. 



Based on the examination of Mcintosh at harvest, codling moth damage 

 was reduced to 1.09 percent on trees in the center of the orchard, and to 

 3 percent on border trees exposed to migration from nearby orchards. 

 Similar records of Northern Spy showed 2.6 percent injury on trees in the 

 center of the block and 4.7 percent on marginal trees. The damage on 

 Rhode Island Greening M^as reduced to 1.4 percent. The control secured 

 on Northern Spy was of particular interest. In 1936 codling moth injury 

 to fruit in that block was estimated at 75 to 80 percent of the crop and 

 was the principal reason for undertaking the test in that orchard. This 

 was the first opportunity of checking the value of the control program on 

 that variety, since Northern Spy is a biennial bearer and the crop of 1938 

 was strewn about promiscuously by the hurricane of that year. 



Apple Maggot Control. (A. I. Bourne and W. D. Whitcomb.) In- 

 spection of fruit at harvest and reports from growers indicate that very 

 generally over the State this pest was somewhat more abundant than in 

 1939 and appears to be building up an infestation to serious proportions. 

 Several factors have produced conditions favorable for such increase. In 

 1937, as a result of low prices, many growers failed to harvest much of the 

 early-maturing fruit and neglected to dispose of dropped apples promptly. 

 In the following year the hurricane disrupted normal harvesting of the 

 fruit and much of it was left in the orchards. In 1939, as a result of the 

 diversion features of the Surplus Commodity Program, much fruit was 

 left under the trees. This combination of circumstances supplied condi- 

 tions very favorable for apple maggot development and explains in great 

 measure why this pest is proving so troublesome in many of the better- 

 cared-for orchards of the State. 



Emergence of apple maggot flies in cages at Wallliam was tlie smallest 

 that has been recorded for several years. In these cages the time of 

 emergence was 4 or 5 days earlier than in 1939. The record is as follows: 



In .SiMi— Ligrht Soil 



Percent 



Emerged Cultivated Sod 



First ily June 2.=; Tune 30 



25% July 3 July 6 



50% July 9 July 9 



75% July 1,^ July l.'^ 



100% July 2S July 2h 



Total 126 121 



% emerged 25.4 24.2 



Insecticides for the Control of European Corn Borer. (A. I. Bourne 



and W. D. Whitcomb.) The cold, wet weather whicli ciiaracterized most 

 of the spring seriously interrupted the seasonal program of many grow- 

 ers, delayed planting, and retarded growth of the crops. In many cases 

 corn was planted later than usual and made very slow growth after 

 germination. Early June was comparatively warm and stimulated the 



