1996 Annual Report for ENE96-017
Teaching to Achieve Sustainable Management of Phytophthora Diseases on Horticultural Crops
Summary
Summary
Agricultural professionals using the right training and educational materials can help farmers to implement ecological approaches for the management of costly losses from Phytophthora diseases through soil and water modifications. Through the training materials developed during this project, misdiagnoses and inappropriate fungicide applications were reduced. Fifty field professionals were trained to recognize symptoms, understand treatments, and advise growers in the use of ecological controls. The project also developed crop-specific fact sheets for growers.
Objectives
To document crop-specific cultural practices known to reduce the incidence and severity of Phytophthora diseases, and to prepare guidelines.
To implement field education that stresses the adoption of cultural practices that can reduce Phytophthora in high-value horticultural crops.
To train participants and users of distributed materials to diagnose field problems accurately and make more judicious use of fungicides.
Specific Project Results
Phytophthora diseases have become damaging to a broad array of high-value horticultural crops in the mid-Atlantic region, leading to millions of dollars of crop loses annually. The threat of Phytophthora can cause growers to choose low-risk, lower-value, but resistant crops over of the high-risk, more valuable ones. By following recommended soil and water management practices, the higher-value crops can be successfully cultivated in high-risk areas. Further, losses from chronic infection in perennial crops such as cranberry can result in 60% crop reductions per year. Deep homogenization offers a non-chemical approach for reducing these losses.
In many cases, Phytophthora disease has become a more limiting factor than market prices or market access for sustaining profitability of high-value crops. In addition to the crop losses, many farmers treat their high-risk crops with fungicide out of fear of devastating crop losses. These applications are costly and often only marginally effective.
This grant sought to define a different approach, concentrating on implementing well-defined soil and water practices first, before resorting to fungicides to reduce losses to Phytophthora diseases. As a result of this grant, we have reversed the order of production recommendations on affected crops; more specifically, fungicide applications are not recommended until soil, crop, and water management strategies have been tried. In some situations, fungicide applications have been reduced or eliminated.
A list of affected crops in the region includes tree fruit (apple, peach), small fruit (blueberry, cranberry, raspberry, strawberry), Solanaceous crops (eggplant, pepper, potato, tomato), all Cucurbit vine crops (cucumber, summer/winter squash, pumpkin), and Ericaceous ornamentals (azalea, rhododendron, pieris, leucothoe). Three disease management fact sheet checklists, designed to be used by agricultural professionals and farmers, were developed for bell peppers, pumpkins, and cranberries. A packaged set of training materials, all developed from validated field research, were prepared as a series of hyperlinked documents distributed on CD.
The CD covers basic biology, life cycles, spore dispersal, methods for isolation from infected host tissues, identification, testing fungicide sensitivity, scenarios for specific crops, mulching practices for disease management, and specific recommendations for peppers, pumpkins, and cranberries.
Other outcomes
The identification of chronic infection as an important component of crop loss in cranberry was in part discovered through research conducted under this grant. Future research could target improved detection methods.
Outreach
A workshop was held September 28 and 29, 1998 called, “Soil and Water Practices to Manage Phytophthora in the Mid-Atlantic Region,” which included USDA personnel, private crop consultants, county agents, specialists, and graduate students from several states. The workshop drew on growers who implemented the project practices as workshop speakers.
A feature article in a professional journal was published (Plant Disease 83 (12): 1080-1089) called, “Ecologically Based Approaches to Management of Phytophthora Blight on Bell Pepper.”
A workshop, “Managing Phytophthora Diseases in Vegetable Crops,” was held at the Annual New Jersey Vegetable Growers Meeting, January 1999. Estimated attendance was over 200 and included growers, researchers, and field professionals.
Training and support material was provided to county agents, and this has resulted in any number of grower education programs in the region, above and beyond the materials developed in the course of this project. One example is the “Mid-Atlantic Pumpkin School,” held in March of 1999.
A hyper-linked document containing educational materials developed during the grant period will be freely distributed on CD and via the Internet.
Reported November 2000