12. 



Trees severely affected in 1979 showed no signs of recovery 

 in 1980 and some died. Injury symptoms did not worsen on trees 

 having only 1 or 2 affected limbs. However, the affected limbs 

 produced little terminal growth in 1980. 



Our experiences with the winter injury of 1979-1980 lead 

 us to conclude that damage to apple trees was most severe on 

 poorly drained soils and that recovery from injury of severely 

 injured trees may be slow. It appears that the best solution 

 to the problem is tree removal. 



********** 



ALTERNATE vs. EVERY MIDDLE SPRAYING FOR APPLE PESTS: 1980 

 RESULTS FOR ARTHROPOD PESTS AND 5-YEAR TRENDS 



W,M, Coli""-, G. Morin^, N.D. Goodhue^, M. Kuzontkoski"^ , T.A. Green^' 



M.R. Paul^, S. Marafino , and R.J. Prokopy 

 Department of Entomology 



In previous issues of FRUIT NOTES, we have reported our 

 findings on the relative effectiveness of alternate-middle vs. 

 every middle spray programs for apple pests in 1976-1979 growing 

 seasons. (See FRUIT NOTES 42(3), 43(3), 44(3), and 45(1). 



Here we present (a) our 1980 findings on alternate middle vs. 

 every middle spraying for insects and mites, (b) a cost-benefit 

 analysis with regard to insect and mite control in 1980 and (c) 

 a summary of pest injuries and cost-benefit analysis for a multiple 

 year period. 



Four test blocks in commercial orchards located in the major 

 fruit-growing regions in Massachusetts were each divided into 2 

 plots of 2-6 acres. One plot received the alternate-middle pro- 

 gram on each spray date throughout the season. The other received 

 the every middle program. Each grower followed his normal spray 

 schedule, using an air-blast sprayer and spray materials and con- 

 centrations (Ix, 4x, etc.) of his own choosing. Except in one 

 block, all trees were fully grown; some on M7 rootstock, others on 

 seedling. Pruning was generally adequate to allow for good spray 

 penetration into tree centers. 



1 



Pest Management Specialist 

 2 



Senior Field Scouts 

 3 



Field Scouts 

 4 



Lab Technician, Entomology Department 

 5 



Extension Entomologist 



