Table 2. Average peak population levels of foliar pests in second-level and first-level IPM blocks. Data 

 are combined for 1992, 1993, and 1994*. 



*Means in each couplet for each cultivar followed by a different letter are significantly different at odds 

 of 7:1. Data represent the average peak percent leaves (for ERM, TSM, LM, WALH, RLH, PLH) or 

 watersprouts (for AA, WAA) infested in 200 leaves or watersprouts (10 from each of 20 trees) sampled 

 at bi-weekly intervals from early June through late August in each type of block each year. Number of 

 blocks containing each cultivar are given in footnote of Table 1. ERM=European red mites; TSM=two- 

 spotted mites; AA=apple and spirea aphids; WAA=woolly apple aphids; LM=leafminers; WALH=white 

 apple leafhoppers; RLH=rose leafhoppers; PLH=potato leafhoppers. 



appleworm, leafrollers, flyspeck, and leafhop- 

 pers. For Delicious, pests not adequately con- 

 trolled under current second-level practices in- 

 clude apple maggot, codling moth, leafrollers, 

 flyspeck, and leafhoppers. It may or may not 

 be coincidence that pest problems under second- 

 level IPM were least for the earliest-ripening 

 cultivar (Mcintosh), intermediate for the 

 middle-ripening cultivar (Cortland), and great- 

 est for the latest-ripening cultivar (Delicious). 

 We intend to conduct further research to deter- 

 mine whether it is fruit-ripening time per se or 

 some peculiar chemical or physical property of 

 each cultivar that accounts for these apparent 

 differences. 



At present, we can recommend with high 

 confidence the use of second-level IPM practices 



for Mcintosh but withhold recommendation at 

 present of their use for Cortland and Delicious 

 pending further investigation. 



Acknowledgments 



This project was funded by the Massachu- 

 setts Society for Promoting Agriculture, the 

 USDA Northeast Regional IPM Competitive 

 Grants Program, State/Federal IPM funds, and 

 the Northeast Regional SustainableAgricultiu"e 

 Research and Education Program. We grate- 

 fully acknowledge the participation of these 

 growers in the project: David Chandler, Dana 

 Clark, Greg Gilmore, Tony Lincoln, Wayne Rice, 

 and Joe Sincuk. 



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Fruit Notes, Summer, 1995 



13 



