EFEITO DA ROTAÇÃO E SUCESSÃO DE CULTURAS NO MANEJO DE NEMATOIDES DA SOJA EM ÁREA ARENOSA.

The objective of this study was to evaluate the effect of summer crops rotation with soybean, corn and crotalaria species and succession with Urochloa ruzizisiensis and Pennisetum glaucum (ADR 300) as cover species on the population of three nematode species of importance for the soybean crop in sandy soils (Pratylenchus brachyurus, Meloidogyne javanica and Heterodera glycines). The experiment was established in naturally infested soil in a randomized complete block design with four replications, in a 5 X 2 factorial scheme (summer crops and intercropping management). The population density of the nematodes in the soil and roots during the harvest and off-season, as well as the dry mass of the cover crops and yield in the subsequent soybean were evaluated. The low population density of nematodes observed in plots cultivated with crotalaria allowed better development of autumn/winter crops (Ruzizigrass and millet). Rotation with Crotalaria spectabilis, C. ochroleuca and C. breviflora resulted in a reduction in the population density of the nematodes in relation to soybean monoculture and rotation with corn. As a positive response, the yield of the subsequent soybean in the plots that received crotalaria were two to three times higher than in those that received the soybean. [ABSTRACT FROM AUTHOR]