Effects of Planting Density and IPM Level 

 on Apple Fruit Quality and Crop Density, 

 1999 Results 



Arthur Tuttie, Jeremy Smith, Chris Bergweiler, Dan McPadden, Steve Christie, 



and Daniel Cooley 



Department of Microbiology, University of Massachusetts 



Starker Wright and Jonathan Black 



Department of Entomology, University of Massachusetts 



Wesley Autio 



Department of Plant & Soil Sciences, University of Massachusetts 



Many New England apple growers have been re- 

 planting their orchards with dwarf trees at densities of 

 400 to 1000 trees per acre. At the same time, our re- 

 search team and a growing number of orchardists are 

 reducing pesticide inputs by employing bio-intensive 

 IPM methods to manage the diseases flyspeck and sooty 

 blotch, pest mites, and the in- 

 sect pests apple maggot and 

 plum curculio. These pests 

 account for almost all pesti- 

 cide applications from about 

 June 10 to harvest. The inte- 

 gration of these horticultural 

 and pest-management prac- 

 tices into a third-level IPM 

 program has been our focus for 

 the last 3 years. This article 

 reports on the effects of plant- 

 ing density and IPM level on 

 apple fruit quality and crop 

 density for the 1999 growing 

 season. 



The tree-fruit research 

 team performed crop density 

 and yield counts and collected 

 apples for analysis in 48 apple 

 orchard blocks as close to har- 

 vest as possible. As with other 

 experiments of this 3-year 

 study, there were six blocks 



per orchard and eight orchards. Blocks were comprised 

 of Mcintosh, with an occasional row of Cortland, or 

 similar cultivar, and were seven rows by seven trees in 

 size. At each orchard, there were two low-density 

 blocks, two medium-density blocks, and two high-den- 

 sity blocks. One block at each density was managed 



Fruit Notes, Volume 64 (Number 4), Fall, 1999 



