Submitted to: Journal of Vegetable Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 24, 2006
Publication Date: July 20, 2007
Citation: Meyer, S.L., Burelle, N.K., Davis, R.F., Thies, J.A., Zasada, I.A. 2007. USDA-ARS research on practices compatible with organic agriculture for management of plant-parasitic nematodes on vegetable crops. Journal of Vegetable Science. 12:47-81. Interpretive Summary: Plant-parasitic nematodes are microscopic worms that cause ten billion dollars in U.S. crop losses annually. Root-knot nematodes are among the most destructive species on vegetable crops. One problem facing growers is the lack of safe and effective methods for controlling nematode-induced crop losses, and this is particularly the case for organic production systems, which do not allow the use of conventional chemical pesticides. Consequently, USDA-ARS scientists in Florida, Georgia, Maryland and South Carolina are conducting research on practices appropriate for organic vegetable farming, and this research is reviewed in this paper along with related fruit crop studies. Management practices being developed include host plant resistance, the application of soil amendments and beneficial microorganisms that promote plant growth or are toxic to nematodes, and the use of cover crops, i.e., plants that are not readily infected by root-knot nematodes and that are grown at a different time from the crop of interest. This research is significant because it is contributing to the development or improvement of nematode management strategies that do not rely on the use of toxic chemicals. This work will be used by scientists, industry and growers developing environmentally safe methods for managing diseases caused by nematodes.
Technical Abstract: The market for organically-grown fruits and vegetables has been increasing in recent years, and research is vital for obtaining optimal quality and yields in organic production systems. Scientists at the United States Department of Agriculture- Agricultural Research Service (USDA-ARS) are investigating methods for managing plant-parasitic nematodes on these crops, and studies that involve practices appropriate for organic farming are reviewed in this paper. All of these projects focus primarily on suppression of root-knot nematode species, including Meloidogyne arenaria, M. hapla, M. incognita and M. javanica. Projects from Florida include investigations of plant growth-promoting rhizobacteria (PGPR) and chitin amendments for management of nematodes on bell pepper (Capsicum annuum), muskmelon (Cucumis melo), strawberry (Fragaria × ananassa) and tomato (Lycopersicon esculentum). A South Carolina research program focuses on the identification, characterization, and development of host plant resistance to root-knot nematodes in bell and hot peppers (Capsicum spp.), southernpea (cowpea; Vigna unguiculata) and watermelon (Citrullus lanatus). Collaborative research in Georgia and South Carolina has concentrated on the utilization of root-knot nematode resistant bell pepper for managing root-knot nematodes in double-cropped squash (Cucurbita pepo cv. Cougar) and cucumber (Cucumis sativus). Research conducted in Maryland studies use of the nematotoxin-producing amendments rye (Secale cereale) and velvetbean (Mucuna spp.) as cover crops, and application of beneficial microbes and their metabolites for suppression of root-knot nematodes on bell pepper, cucumber, tomato and muskmelon. This research contributes to development or improvement of nematode management strategies that do not rely on the use of toxic chemicals.