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The multi-state project has 3 objectives: <OL> <LI> Develop cultural controls for plant-parasitic nematodes based on resistant, non-host, or nematode-antagonistic rotation crops and green manures<LI> Develop biological control agents, such as Pasteuria penetrans, for suppression of plant-parasitic nematodes<LI>Determine the effects of cultural and biological controls of plant-parasitic nematodes on nematode community ecology dynamics at the trophic group level</ol>
Expected outputs are 6-fold: <OL> <LI> Research on cultural controls for plant-parasitic nematodes using resistant, non-host, or nematode-antagonistic rotation crops and green manures will increase our knowledge on nematode dynamics and damage, and will result in the publication of numerous peer-reviewed journal articles and technical articles<LI>Information will be developed about the efficacy of candidate biocontrol products<LI>The documented increases or decreases in nematode diversity will be correlated with management practices and soil properties such as moisture, fertilizers, chemical treatments, rotation crops, etc. Increased nematode diversity should relate to increased crop yields and/or reduced input costs for disease or plant-parasitic nematode control. This should provide tillage systems that can be used by growers to better manage soil systems and reduce cost for disease and plant parasitic nematode control<LI>Technology will be developed that improves the application efficiency of biological products for control of plant pathogenic nematodes. These products and practices will include commercially available transplants, transplant mixes, and microbial products that enhance plant growth, reduce nematode infestation, and increase yield <LI>Research at golf course sites throughout Southern New England will document nematode species present, fungal and bacterial antagonists, a wide variety of accompanying soil characteristics and the chemical and cultural practices implemented on the sample sites. The research will result in basic knowledge about the biology of potential management agents and the modes of actions of such agents, which will be reported through scientific publications and presentations. The work will lead to development of nematode management products containing microbes or microbially based compounds<LI>Publication and distribution of extension publications on the host status of different cover and rotational crops to major nematodes and effects of soil management practices on nematodes and their damage.
NON-TECHNICAL SUMMARY: 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.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. This project will evaluate alternative cropping systems, biological materials for pest management, and gain a better understanding of the biological diversity in soil that leads to natural disease suppression. 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. <P>
APPROACH: Objective 1. Scientists will search for resistance to Meloidogyne hapla in vegetable crops (onion and carrot, NY; and pepper, ARS-USDA - SC) and also to root-lesion nematode in vegetable (onion and beans, NY), small fruit (strawberries, CT), and rotational grain crops (rye, wheat, soybean, vetch; CT, PA, and NY). New rotational combinations of vegetable crops will be developed and tested for effectiveness in managing Meloidogyne spp. including double-cropping systems (susceptible vegetable crops after resistant cvs.).The use of summer cover crops of RKN-resistant cowpea and sunn hemp for managing RKN in vegetable crops and the effects of these practices on soil microbial and nematode communities will be investigated(FL, ARS-USDA- SC, and ARS-USDA- FL).Scientists will assess the impact of nematode-antagonistic rotational or cover crops on populations of lesion and root-knot nematodes, and the impact of such antagonistic crops on nematode damage to vegetable crops in CT, PA, and NY. <P> Objective 2 will be addressed by two approaches. First, sequence relationships of the biocontrol bacterium, P. penetrans spp. will be determined, nucleic acid and antibody probes developed and applied to soil to test for their potential for suppression of nematode infestation (UF - FL). Second, the natural suppression and efficacy of commercially available biorationals will be evaluated (UF - FL, MA, & RI). Examples include Arthrobotrys in golf greens, commercially available formulations of Paecilomyces lilacinus, gram-positive bacteria including Bacillus spp. and Streptomyces spp. Various types of microbes and natural product formulations will be tested for production of compounds toxic to nematodes. <P>Objective 3 Scientists in six states will conduct complementary or collaborative studies to assess the impact of rotation and cover crops on plant-parasitic nematode populations and nematode community structure.Long-term population dynamics of plant parasitic and other nematode trophic groups will be monitored at the Kellogg Biological Station LTER site (MI) and at the West Virginia University Organic Research Farm (WV), where ongoing farming systems studies are underway. Multi-year rotations are being compared under several conventional and organic farming systems to evaluate interrelationships among farming practices on nematode community structure. In addition, effects of farming systems on other nematode biocontrol agents (trapping fungi and nematode predators) will be evaluated (WV) to identify farming practices that best enhance indigenous nematode biocontrol activity. Scientists will either determine nematode community structure based on trophic group (AL, CT, MA, NY) or on more detailed identification to genus (MI, WV). Maturity and diversity indices will be calculated and correlated to crop yield. Butyric and propionic acid are extremely effective as preplant nematicides (RI). Participant Neher (VT) will be involved in Objective 3.