Cowpea cover crop and solarization for managing root-knot and other plant-parasitic nematodes in herb and vegetable crops

Authors Wang, KH; McGovern, RJ; McSorley, R; Gallaher, RN

Journal SOIL AND CROP SCIENCE SOCIETY OF FLORIDA PROCEEDINGS , 2004,:63

Abstract Field experiments were conducted to evaluate three non-chemical alternatives to methyl bromide for the management of plant-parasitic nematodes on basil (Ocimum basilicum L.) and Chinese cabbage (Brassica chinensis L.). Five pre-plant treatments were 1) summer cover crop of cowpea [Vigna unguiculata (L.) Walp.], 2) soil solarization during autumn, 3) cowpea + solarization, 4) nontreated control and 5) fumigation with methyl bromide. At planting, each treatment was split with and without application of a commercial rhizobacterial product (PGA(-)). Cowpea treatment suppressed populations of root-knot [Meloidogyne incognita (Kofoid & White) Chitwood] and stubby-root [Paratrichodorus minor (Colbran) Siddiqi] nematodes at termination of the cover crop and at basil harvest, but not at Chinese cabbage harvest. Methyl bromide-treated plots had lower (P less than or equal to 0.01) numbers of awl (Dolichodorus heterocephalus Cobb) and sting (Belonolaimus longicaudahis Rau) nematodes and produced higher basil yield than those receiving the cowpea cover crop treatment. However, cowpea resulted in a slight yield benefit on Chinese cabbage, possibly due to a green manure effect from cowpea. Solarization was ineffective due to atypically cloudy weather that resulted in lower than expected soil temperatures and heavy growth of nutsedge (Cyperus spp.). Biocontrol with rhizobacteria was largely ineffective, and only suppressed population densities of sting nematode on Chinese cabbage. The cowpea cover crop was the most effective non-chemical alternative, however, the performance of individual non-chemical tactics must be improved before they can be integrated effectively to match fumigation with methyl bromide.

Species covered 豇豆 Vigna unguiculata 罗勒(变种) Ocimum basilicum 小白菜 Brassica chinensis