CROP ROTATION FOR PRATYLENCHUS BRACHYURUS CONTROL IN SOYBEAN

Abstract

In recent years, the root-lesion nematode (Pratylenchus brachyurus) has been responsible for damage and economic losses in various crops and numerous regions throughout Brazil. The aim of this study was to evaluate the effects of succession cropping on the population of P. brachyurusin soybean. Two experiments were carried out in the greenhouse, using soil naturally-infested with nematodes and the following cropping sequence: soybean (90 d)-treatment (60 d)-soybean (60 d). The treatments were soybean (control), maize, brachiaria grass, intercropped maize-brachiaria, crotalaria, oilseed radish, stylosanthes, and fallow. In the first experiment, the nematode population under brachiaria and intercropped maize-brachiaria was lower that with maize and soybean, but in the second experiment, there was no statistical differences compared to maize. Crop succession with crotalaria, oilseed radish, stylosanthes and fallow promoted the greatest reductions in the population of P. brachyurus.Nos ultimos anos, os nematoides das lesoes radiculares, Pratylenchus brachyurus, tem causado danos elevados e perdas economicas em diversas culturas, em varias regioes brasileiras. Portanto, o trabalho teve como objetivo avaliar o efeito de plantas usadas em sucessao com a soja sobre a populacao de P. brachyurus. Dois experimentos foram conduzidos em casa de vegetacao, com solo naturalmente infestado pelo nematoide, usando a sequencia de cultivo: soja (90 dias)-tratamento (60 dias)-soja (60 dias). Os tratamentos avaliados foram soja (testemunha), milho, braquiaria, consorcio milho-braquiaria, crotalaria, nabo forrageiro, estilosantes e pousio. No primeiro experimento, a populacao do nematoide nos tratamentos braquiaria e consorcio milho-braquiaria foram inferiores ao milho e a soja, porem no segundo experimento nao diferiram estatisticamente do milho. A sucessao de culturas com crotalaria, nabo forrageiro, estilosantes e pousio promoveram as maiores reducoes na populacao de P. brachyurus.