Assessing new methods of integrated pest management for apples in the Midwest

The following summary is from Adam Sisson’s thesis chapter on sustainable apple production systems incorporating scab-resistant cultivars. The research was carried out with the assistance of Mark Gleason and his lab at the Department of Plant Pathology, Iowa State University, Ames. The result are still in a preliminary stage and the researchers are waiting for a third year of data, before the results will be made public. If interested please contact Mark Gleason at mgleason@iastate.edu
Four management strategies were compared in an Iowa apple orchard for management of codling moth, sooty blotch and flyspeck (SBFS), weeds, and other pests. In an orchard block with three apple scab-resistant cultivars (Redfree, Liberty, and Goldrush), two new integrated pest management (IPM) systems that incorporated weather-based disease-warning systems and alternative pesticides (Treatments 3 and 4) were compared to an existing IPM regime (Treatment 2) and a conventional system with calendar-based timing of fungicide and insecticide sprays (Treatment 1). At harvest, mean incidence (%) of fruit with disease or insect injury was recorded and marketable and cull fruit were counted and weighed.
The two new IPM strategies were as effective as calendar-based and existing-IPM treatments for most apple pests, and yields were equivalent. A partial budget analysis indicated that Treatment 4 was the least expensive for larger orchards and Treatment 3 was the most expensive for all orchard sizes. Treatment 4 had the least pesticide applications during the 2008 growing season. Active ingredients, spray rates, and applications of pesticides were used to develop an environmental risk rating for each treatment. New IPM treatments lowered ecological risks compared to calendar-based spraying and existing IPM. Composted hardwood mulch was also compared with bare soil for weed control efficacy; mulch suppressed weed coverage and biomass compared to bare soil and required fewer herbicide applications.