Related Research and Adaptive Studies 



An important part of 1987 activity involved cm- 

 barking on the second stage of apple IPM in a large number 

 of commercial orchards. Second-stage IPM projects focus- 

 ing on apple maggot fly (the key insect pest after May) and 

 key Icpidopteran pests and on phytophagous mites and 

 apple scab were initiated with funding from outside grants. 

 As part of the mite biocontrol project, groundcover surveys 

 of 36 second-stage blocks were undertaken. Results of 

 these surveys will enable us to establish orchard classifica- 

 tions (mowing vs. herbicide, hard vs. soft spray program, 

 and broadleaf vs. grass groundcover) prior to the start of 

 1988 mite sampling. We wish to acknowledge the signifi- 

 cant contribution of James Williams and Karen Hauschild 

 who assisted with these surveys, and Dr. Prasanta 

 Bhowmik, who provided training and assistance in orchard 

 weed identification. We will report more fully on all 

 second-stage IPM projects in other Fniil Notes articles. 



Fungicide, insecticide, and insect growth regula- 

 tor trials again were performed at the HRC and at grower 

 sites in 1987. This activity involved testing chem icals which 

 may be or presently arc a component of commercial spray 

 programs. Evaluation of pesticide effects on mite preda- 

 tors continued, as did the evaluation of disease-resistant 

 apple cultivars. Monitoring continued in a commercial test 

 block of disease-resistant cultivars established at the Rice 

 farm in Wilbraham. This planting is intended to determine 

 the feasibility of using no fungicides and a minimum of 

 insecticides in a commercial setting. 



A set of 5 ergosterol biosynthesis-inhibiting 

 chemicals (Si's) was tested at 10-day application intervals, 

 following delayed application (tight cluster was the first 

 application). This study was designed to test the feasibility 

 of increasing intervals and delaying the first fungicide 

 application using Si's. This work will be described in other 

 Fmil Notes articles. 



IPM blocks at the HRC were treated with a 

 registered SI (RubiganTM) on a delayed application basis 

 under Plant Pathology supervision. Effective control was 

 obtained with 2 fewer fungicide applications than in previ- 

 ous seasons. Another experimental material (not an SI), 

 with potential for long-term residual fungicidal activity 

 combined with low environmental hazard, was tested. Two 

 applications of the material, made in early and late June, 

 effectively stopped scab development. Next season, the 

 material will be tested in a series to determine whether it 

 might offer a means for drastically reducing summer cover 

 sprays and possibly primary season sprays as well. 



Two root fungicides and various planting hole 



amendments were tested for effect on early tree growth. 

 This experiment is a continuation from 1986 and indicates 

 that a 50% peat amendment and one of the fungicide 

 treatments (AlietteTM) are the two most effective tech- 

 niques for promoting the growth of newly planted trees. A 

 further report will appear in a future Fruit Notes article. 



Daniel Cooley began work on a regional IPM 

 project with Dr. William MacHardy (NH) and Dr. David 

 Roscnberger (NY), to determine if the scab inoculum dose 

 from the previous season will predict the length to which 

 the first application of fungicide can be delayed the follow- 

 ing season. One Massachusetts orchard was involved in 

 this study, and plans were to expand the project to second 

 stage IPM blocks last fall. 



Cooley also developed a prototype expert .systems 

 (computerized decision support software) for apple scab 

 and apple root problems in conjunction with Dr. Paul 

 Cohen of the Computer and Information Science Depart- 

 ment, using Public Service Grant funding. We have been 

 exploring ways to integrate this technology into the overall 

 IPM program. 



Disease-resistant apple cultivar evaluation con- 

 tinued, with emphasis on horticultural factors, such as 

 maturity and storability. Plans were made and funding 

 obtained for a major disease resistant block at the HRC. 

 Observation of an immature block planted in Wilbraham 

 continued, and bud wood was distributed to a commercial 

 grower, suggesting that such a program might promote 

 disease-resistant cultivars. 



Related entomology research and adaptive stud- 

 ies in Prokopy's lab continued to focus on improvement of 

 monitoring traps for apple Icafminers and on the host- 

 finding behavior of the apple maggot fiy and the plum 

 curculio. Other related entomology studies involved a test 

 of insecticidal soap against pear psylla (Psylla pyricola), the 

 most important pear pest in most orchards. In cooperation 

 with Dr. Alan Eaton, University of New Hampshire, we 

 continued tosurvey the distribution, in New England, of the 

 European apple sucker, Psylla mail, potentially a serious 

 pest in commercial blocks in the future. Although not yet 

 found as a pest in commercial orchards, P. mali appears to 

 be present in abandoned orchards throughout the central 

 and western counties in Massachusetts, west into New 

 York's Hudson Valley and south into Connecticut. 



Plans for 1988 



We propose to continue most of the 1987 activi- 

 ties, including: monitoring weather, pathogens, arthro- 



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