received no summer fungicide. First-level IPM blocks 

 did not have enough flyspeck to analyze. In 1 995, there 

 were more flyspeck symptoms in blocks that were 

 relatively flat than in steep-sloped blocks (r", or amount 

 of variation explained, was 0.17, or 17%), and the 

 amount of flyspeck was higher in blocks that were 

 relatively low in elevation within the orchard (r- = 

 0. 12). Other factors that had positive but less significant 

 impacts (r^ < 0.03) were height of apple trees, proximity 

 of apples to border areas, and density of host-plants in 

 the borders. 



hi 1996, the significant site factors (Table 1) were 

 density of flyspeck on host-plants in borders (r^ = 0.13), 

 lack of slope of the block (r^ = 0.05), and height of the 

 apple trees (r^ = 0.04). The factors which contributed 

 only marginally to explaining the variability in flyspeck 

 incidence (r^ < 0.03) were number of borders adjacent 

 to a block of apple trees and proximity of brambles in 

 the borders to the apples. 



In summary, the site factors that were the most 

 important during 1995 and 1996 (explained at least 

 10% of the variability) were slope and relative 

 elevation in 1995 and density of flyspeck on host- 

 plants in borders in 1996. 



In 1997-1999, a different group of blocks was 

 evaluated for site factors and flyspeck infection. In 

 this experiment, two of the key factors were planting 

 density/tree size and IPM level. A main objective of 

 the study was to evaluate the effectiveness of the range 



of IPM strategies that had been developed using fairly 

 large semi-dwarf trees on plantings that included dwarf 

 trees at high densities. Each of eight participating 

 orchards provided two blocks of low density/large trees, 

 two blocks of medium density/medium-sized trees, and 

 two blocks of high density/small trees. The blocks that 

 had the same planting density were divided into two 

 groups: half were managed with first-level IPM 

 strategies and half with "third-level" IPM strategies. 

 The progression to third-level IPM was marked by the 

 integration of advance pest-management strategies with 

 horticultural strategies at the level of the whole orchard. 

 The third-level blocks, which were seeded with 

 beneficial mites and were managed with biologically- 

 based third-level strategies for insects, received reduced 

 rates or frequencies of fungicide applications, little or 

 no EBDC fungicide, and only captan or benomyl after 

 June 15. The first-level blocks were managed with the 

 growers' choices of materials and frequencies of 

 application. The blocks within a pair were not 

 contiguous. They were often at either end of a long 

 section of 'Mcintosh' or 'Cortland' rows and were 

 bordered by a wide variety of habitats. Some of the 48 

 blocks were surrounded by other rows of apple trees, 

 some by grassy fields, others by dense woods or 

 shrubby hedgerows. 



During each growing season, the blocks and their 

 surrounding borders were rated for static orchard 

 factors which had proved significant in the earlier study. 



Fruit Notes, Volume 67, Winter, 2002 



