Effects of Planting Density and IPI\/I Level 

 on Apple Fruit Quality 



Arthur l\ittle, Deirdre Smith, James Hall, Michael Frank, and Daniel Cooley 

 Department of Microbiology, University of Massachusetts 



Starker Wright, Jon Black, and Stephen Lavalle 

 Department of Entomology, University of Massachusetts 



Wesley Autio 



Department of Plant and Soil Science, University of Massachusetts 



Many New England apple growers have replanted 

 their orchards with dwarf at densities of 400 to 1000 

 trees per acre. At the same time, growers have been 

 advancing their efforts to reduce pesticide inputs on 

 their land by employing bio-intensive IPM methods to 

 manage flyspeck disease, plum curculio, pest mites, 

 and apple maggot fly, which together account for al- 

 most all pesticide use from about June 10 to harvest. 

 The tree fruit research and extension team at 

 the University of Massachusetts and eight 

 growers have been integrating these horticul- 

 tural and pest-management practices for the 

 last 2 years. 



Just before commercial harvest in 1997, 

 100 fruit were examined from each of the 48 

 blocks for symptoms of disease and arthro- 

 pod damage. As in other experiments of this 

 3-year study, there were six blocks per orchard 

 and eight orchards. At each orchard there 

 were two high-density blocks, two medium- 

 density blocks, and two low-density blocks. 

 Half of the blocks were managed according 

 to third-level IPM strategies, and half were 

 managed with traditional first-level IPM. 

 The blocks were Mcintosh, with an occasional 

 row of Cortland or similar cultivar, and were 

 seven rows by seven trees or as close to this 

 as possible. The feat of selecting and map- 

 ping the 48 blocks in eight orchards across 

 the state was considerable and could not have 

 been done without a very supportive and pro- 

 active grower community. 



A sub-sample of 20 fruit were selected 



from each group of 100 for fruit quality evaluations. 

 The 20 were weighed. The percent red color was de- 

 termined. Firmness was assessed with an Effigi pen- 

 etrometer, and juice was collected from this process. 

 The percent soluble solids was assessed in the juice 

 with a hand refractometer. 



Fruit quality was not affected in 1997 by planting 

 density or IPM level. We hoped that fruit produced 



Table 1. Fruit quality (1997) and crop density (1998) of 

 apples from blocks of different planting densities and IPM 

 levels in eight Massachusetts orchards.* 



* Means within column and Ueatment type not followed 

 by the same letter are significantly different at odds of 19 

 to 1. 



Fruit Notes, Volume 64 (Number 2), Spring, 1999 



