Ninety-eight percent of the isolations from apples with early 

 symptoms yielded S. sclerotiorum and 601 were pure culture. This, 

 plus pathogenicity test results, indicated that S. sclerotiorum 

 was the probable cause of calyx-end rot. Isolations from fruit 

 with advanced symptoms showed a marked decrease in S. scle r otiorum 

 and an increase in the isolation of other saprophytic and weakly 

 pathogenic fungi. This illustrates the importance of early dia- 

 gnosis in determining the cause of a calyx-end rot disease of 

 apple. 



Our observations indicate that an adequate apple scab spray 

 program may not prevent an outbreak of calyx-end rot, as both of 

 the affected orchards surveyed had excellent management of all 

 other apple diseases. 



********** 



DISEASE RESULTS FOR THE 1980 INTEGRATED PEST MANAGEMENT 

 PROGRAM FOR APPLES IN MASSACHUSETTS 



T.R. Bardinelli-^, C.W. McCarthy^, and W.J. Manning^ 

 Department of Plant Pathology 



During the 1980 growing season, 11 commercial apple orchards 

 cooperated in the disease management aspect of the Integrated 

 Pest Management (IPM) Program. IPM and Check blocks were located 

 in the same orchards. 



The disease management strategy for the IPM program was based 

 on biological and environmental monitoring, such as apple scab asco- 

 spore release data, tree growth stage, length of leaf wetting per- 

 iods, and average temperature during these wetting periods. These 

 factors were most important during the primary apple scab season, 

 as determined by the period of ascospore release. Spray decisions 

 were based on the Mill's Table which gives the approximate number 

 of hours of leaf wetting required at various temperatures for the 

 occurrence of a light apple scab infection. 



1 



Extension Technician 

 2 



Extension Aide 

 3 



Associate Professor 



