Evaluation of green covering potential and crop rotation systems in the suppression of the ring nematode em pre-plantio ao pessegueiro

• Published in: Revista Brasileira de fruticultura Vol. 32; no. 1; p. 74
• Main Authors: Gomes, Cesar Bauer, Carvalho, Flavio Luiz Carpena, Junior, Joao Guilherme Casagrande, Radmann, Elizete Beatriz
• Format: Journal Article
• Language: Spanish
• Published: Sociedade Brasileira de Fruticultura 01.03.2010
• ISSN: 0100-2945

In a field naturally infested with ring nematode (Mesocriconema xenoplax), green covering were tested for their suppressing potential in winter and summer crops comparing to plots kept in fallow lands. Tree crop rotation system with the same plant species tested before (black oat/pig bean/ millet/forage radish; forage radish/ millet/white oat/corn; and white oat/ dwarf velvet bean /wheat/sorghum) were evaluated for suppression potential to nematode M. xenoplax for two years, using as control, plots that were kept in fallow lands. The experiments were conducted in the field in a randomized block design with six repetitions. Before and after the establishment of each plot, the nematode populations were evaluated on the number of M. xenoplax/100[cm.sup.3] of soil and the reproduction factor (RF= final population/initial population) of the ring nematode, where RF<1,00 showed suppression and RF > 1,00, favoring of the reproduction. Most of the crops analyzed were unfavorable host (RF < 1,00) of M. xenoplax, except the dwarf velvet bean that behaved as favorable to the nematode reproduction. Although all treatments have suppressed M. xenoplax, the crop rotations forage radish/ millet/white oat/corn and white oat/ dwarf velvet bean /wheat/sorghum realized the largest reduction of the nematode in the soil (93-95%).It was noted a sharp decline in the M. xenoplax population in the first two crops, with later stabilization of its level, regardless of the studied system. Index terms: Mesocriconema xenoplax, peach tree short life, soil management, crops rotation, host suitability. Em uma area naturalmente infestada com o nematoide anelado (Mesocriconema xenoplax), coberturas verdes foram testadas quanto a sua hospedabilidade, em cultivos de inverno e verao, comparativamente as parcelas mantidas sob pousio. Tres sistemas de rotacao de culturas, com as mesmas especies vegetais testadas anteriormente (aveia-preta/feijao-de-porco/milheto/nabo-forrageiro; nabo-forrageiro/ milheto/aveia-branca/milho, e aveia-branca/mucuna-ana/trigo/sorgo), foram avaliados quanto ao potencial supressor do nematoide de M. xenoplax por dois anos, utilizando-se, como testemunhas, de parcelas mantidas sob pousio e alqueive. Os experimentos foram conduzidos a campo, em blocos ao acaso, com seis repeticoes. Antes e apos o estabelecimento de cada cultivo, as populacoes do nematoide foram avaliadas quanto ao numero de M. xenoplax/'100[cm.sup.3] de solo e fator de reproducao (FR= populacao final/populacao inicial) do nematoide anelado, onde FR < 1,00 indicou supressao e FR > 1,00, favorecimento da reproducao. A maioria das culturas testadas foi hospedeira desfavoravel (FR < 1,00) de M. xenoplax, exceto a mucuna-ana, que se comportou como favoravel a reproducao do nematoide. Embora todos os tratamentos tenham suprimido M. xenoplax, as rotacoes nabo-forrageiro/milheto/aveia-branca/milho e aveia-branca/mucuna/ trigo/sorgo prorcionaram as maiores reducoes do nematoide no solo (93-95%). Constatou-se maior queda nas populacoes de M. xenoplax nos dois primeiros cultivos, com posterior estabilizacao de seus niveis, independentemente do sistema estudado. Termos para Indexacao: Mesocriconema xenoplax, morte precoce do pessegueiro, manejo de solo, rotacao de culturas, hospedabilidade.