Tropical Rotation Crops Influence Nematode Densities and Vegetable Yields


  • R. McSorley
  • D. W. Dickson
  • J. A. de Brito
  • R. C. Hochmuth


The effects of eight summer rotation crops on nematode densities and yields of subsequent spring vegetable crops were determined in field studies conducted in north Florida from 1991 to 1993. The crop sequence was as follows: (i) rotation crops during summer 1991; (ii) cover crop of rye (Secale cereale) during winter 1991-92; (iii) 'Lemondrop L' squash (Cucurbita pepo) during spring 1992; (iv) rotation crops during summer 1992; (v) rye during winter 1992-93; (vi) 'Classic' eggplant (Solanum melongena) during spring 1993. The eight summer crop rotation treatments were as follows: 'Hale' castor (Ricinus communis), velvetbean (Mucuna deeringiana), sesame (Sesamum indicum), American jointvetch (Aeschynomene americana), weed fallow, 'SX- 17' sorghum-sudangrass (Sorghum bicolor x S. sudanense), 'Kirby' soybean (Glycine max), and 'Clemson Spineless' okra (Hibiscus esculentus) as a control. Rotations with castor, velvetbean, Americanjointvetch, and sorghum-sudangrass were most effective in maintaining the lowest population densities of Meloidogyne spp. (a mixture of M. incognita race 1 and M. arenaria race 1), but Paratrichodorus minor built up in the sorghum-sudangrass rotation. Yield of squash was lower (P = 0.05) following sorghum-sudangrass than after any of the other treatments except fallow. Yield of eggplant was greater (P = 0.05) following castor, sesame, or American jointvetch than following okra or fallow. Several of the rotation crops evaluated here may be useful for managing nematodes in the field and for improving yields of subsequent vegetable crops. Key words: Aeschynomene americana, castor, crop rotation, cropping systems, Cucurbita pepo, eggplant, fallow, Glycine max, Hibiscus esculentus, jointvetch, Meloidogyne arenaria, Meloidogyne incognita, Mucuna deeringiana, nematode management, nematode, okra, Paratrichodorus minor, Ricinus communis, sesame, Sesamum indicum, Solanum melongena, Sorghum bicolor, sorghum-sudangrass, soybean, squash, sustainable agriculture, vegetables, velvetbean, weed hosts.