NE1019: Alternative management systems for plant-parasitic nematodes in horticultural and field crops
Statement of Issues and Justification
The need. Plant-parasitic nematodes cause major economic losses to horticultural and field crops in the U.S. Current control methods rely largely on nematicides (both fumigant and non-fumigant types) for most crops and pre-plant soil fumigation with the broad-purpose fumigant methyl bromide for high value fruit and vegetable crops. However, there are serious concerns about the use of nematicides in terms of food safety and environmental quality issues. In addition, methyl bromide is proposed to be withdrawn from use in the U.S. in 2005. Alternative environmentally compatible control strategies that use bio-based options (including resistant, non-host, or antagonistic crop cultivars and biological control agents) are urgently needed to replace high-risk chemical nematicides.Importance of work and consequences if not done. Identification, characterization, and enhancement of resistant crop germplasm, antagonistic crops cover crops, and biocontrol agents are essential for the development of bio-based management options against plant-parasitic nematodes. Assessment of the effects of such management techniques on diversity of both plant-parasitic and free-living nematodes will increase our understanding of soil health and aid in development of sustainable crop management. If this work is not done, crop production will continue to move offshore where environmental standards for pesticide use are less stringent and our supply of safe, inexpensive grains, fruits, and vegetables will dwindle. Moreover, local farmers will lose market share and have reduced opportunities for economic development.
Technical feasibility of work. NE-171 is one of the most productive regional research groups nationwide. Members and collaborators of NE-171 (nematologists, molecular biologists, plant breeders, and extension specialists) have the demonstrated expertise to accomplish the proposed objectives and to continue serving stakeholders. During the first three years of the current project (2000 ? 2002), NE-171 members have published 95 refereed research papers, book chapters, technical and extension publications, and popular articles. Accomplishments of the current NE-171 project include: identification and characterization of fruit and vegetable germplasm and cultivars (pepper, strawberry, onion, and watermelon) that are resistant or tolerant to nematodes; validation of alternative nematode management tactics in vegetable crop production; demonstration that green manure crops suppressed plant-parasitic nematodes and weeds in orchard replant sites; and development of an immunoassay for quantitative measurement of P. penetrans endospores in soil and infected nematodes.
Advantages of a multistate effort. Interactions of scientists from several states who share the common goal of developing bio-based alternatives to manage plant-parasitic nematodes will be highly advantageous for several reasons: i) nematode-resistant and antagonistic crop germplasm and biocontrol agents must be tested in a wide range of environments against several nematode species and populations to determine their best utilization; ii) different strains of biocontrol organisms are likely to be discovered in different geographical areas and different cropping systems thus providing a potentially diverse array of new biocontrol agents; iii) the breadth of knowledge and experience of scientists participating in the northeastern region will lead to unique approaches and solutions to research problems that are beyond the scope of a single researcher or even a single institution.
Impacts of work. The long-term impacts of research efforts in the northeastern region will be a better understanding of bio-based cropping systems and lead to future alternatives for the reduction and dependency on nematicides and simultaneously increasing soil health. Specific examples of short-term impacts include management of potato early dying and black root rot of strawberry through development of green manure and antagonistic cover crops; development of cropping schemes using root-knot nematode (RKN) resistant vegetable and non-host cover crops that will allow growth of subsequent susceptible vegetable crops without nematicides; identification of low-risk nematicides and biological products on horticultural crops; development of orchard re-plant methods using antagonistic and/or non-host cover crops that will eliminate the need for nematicide applications; the molecular characterization of Pasteuria penetrans that will facilitate detection and quantification of P. penetrans populations, and further the development of methods to produce P. penetrans with nematode/host specificities for use in management of RKN species in a wide range of crops.
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