- Fruits: apples, general tree fruits
- Crop Production: application rate management
- Education and Training: decision support system, extension, participatory research
- Farm Business Management: budgets/cost and returns, risk management
- Pest Management: cultural control, economic threshold, field monitoring/scouting, genetic resistance, integrated pest management, weather monitoring
- Production Systems: agroecosystems, holistic management, permaculture
- Soil Management: organic matter, soil quality/health
This 3-year systems-level project showed that scab resistant varieties, a disease-warning system, and mulching can enhance sustainability of Iowa apple orchards. Combining scab-resistant varieties with a warning system for sooty blotch and flyspeck disease resulted in fewer pesticide sprays and spray trips, lower pest management costs, and sharply reduced environmental impact compared to either calendar-based spray timing or a standard IPM program, with equivalent yield and fruit quality. Mulching with composted hardwood bark mulch reduced reliance on chemical herbicides and resulted in soil that was cooler, moister, and higher in organic matter than in bare-ground plots. The project also showed that high-quality hard cider can be produced from Iowa apples, including scab-resistant varieties, as a value-added product for apple growers. Results were shared with Iowa growers through field days and annual research reports.
Commercial apple orchards in the North Central Region face serious challenges to sustainability: shrinking profit margins, loss of mainstay pesticides, and the demise of key IPM programs.
Midwest growers suffer competitive disadvantages because diseases, insect pests, and weed pressure far exceed those of major competitors: Washington State, Chile, and New Zealand. Therefore, growers need to carve out specialized niches – such as unique varieties and value-added products – that are a good fit for Midwest conditions.
IPM strategies against apple scab, the number one apple disease, have collapsed following proliferation of fungicide resistance by the scab pathogen. The result is that Midwest growers must now return to calendar-based fungicide spray timing – almost the same as a generation ago – with many more sprays required. A shift to apple varieties which are highly resistant to apple scab could help to overcome this problem.
In 2006, EPA announced a phase-out of Guthion, the most widely used organophosphate (OP) insecticide for codling moth (the number one insect pest of apple) and greatly increased restrictions on use of Imidan, the other popular OP. New, lower-risk strategies are needed against codling moth.
Sooty blotch and flyspeck (SBFS), a disease caused by a complex of fungi, is the main reason Midwest growers apply 4 to 6 fungicide sprays in the summer. Disease-warning systems for SBFS allow growers to save some of these sprays, but need to be fine-tuned to be used reliably in the Midwest.
Conventional herbicides are often used to suppress weeds in tree rows, but the resulting bare soils can degrade soil quality and increase erosion. Grasses within rows hold the soil but competition for water can stunt apple trees. Organic mulches have been proposed as alternatives to overcome these problems, but have not been evaluated in the Midwest.
Hard cider offers an opportunity for adding value to apples, but few North Central Region growers currently produce this fermented product. However, hard cider could develop into a value-added and agri-tourism opportunity. Research is needed on how to produce a consistently high-quality product that appeals to Midwest consumers.
Our project attempted to meet these pest-management and value-added needs in an integrated 3-year project based in Iowa.
Project objectives:div style="margin-left:1em;">
Objective 1: Compare innovative practices to conventional IPM and traditional practices for disease, insect, and weed management in annual field trials.
Objective 2: Develop methods for producing hard apple cider of consistently high quality that Midwest consumers are willing to buy.
Objective 3: a) Calculate the costs, benefits, and risks of the alternative apple management systems in Objective 1; b) Estimate the costs, benefits, and risks associated with local-scale manufacturing and marketing of hard cider in Iowa.
Objective 4: Communicate project findings to North Central Region apple growers through on-farm demonstration trials, field days, meeting presentations, statewide and regional newsletter and trade-journal articles, a project website, press releases, and an on-line Extension bulletin.
Performance targets for research, stated in the project proposal: field validation of best management practices that integrate current disease, insect pest, and weed management innovations with disease-resistant apple varieties; cost-benefit and environmental impact analyses of each strategy; hard cider production methods that produce a superior product; and refereed publications in technical journals. Outreach targets included: three field days; nine presentations at regional grower meetings; articles in Fruit Growers News; a project website; and an on-line extension bulletin