ABSTRACT
One of the goals of our research in pest management is to understand how the pests of cotton (Gossypium hirsutum L.) interact in the production system. In 1982 we established field research to study the interaction of two pests, the root-knot nematode, Meloidogyne incognita (Kofoid & White) Chitwood, and the cotton bollworm, Heliothis zea (Boddie). In addition to the cotton pests, we also sampled for vesicular - arbuscular (VA) mycorrhizae of cotton. In previous work, we found that cotton roots in Arkansas fields were typically infected with VA mycorrhizal fungi in the genera Gigaspora and Glomus (2,3). In the experiments described here, we examined the relationship of VA mycorrhizae to populations of root-knot nematodes. Greenhouse studies by Roncadori and Hussey (6) and Hussey and Roncadori (4) indicated that VA mycorrhizae altered the life histories of nematodes and that mycorrhizal infection ameliorated growth reductions associated with nematode infection. Work by Rich and Bird (5) showed a negative correlation between mixed populations of nematodes, including M. incognita, and VA mycorrhizae. Our plan in the work discussed here was to describe how VA mycorrhizae interact with nematode populations and plant growth and how insect populations were related to nematode infected plants in contrast to healthy plants.
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