Levantamento de espécies e raças de Meloidogyne em cafeeiros no estado do Paraná

Abstract

Pelo grande potencial de causar prejuízos significativos e comprometer o solo de lavouras cafeeiras, os fitonematóides do gênero Meloidogyne ocupam posição de destaque entre os vários patógenos que reduzem a produção. O controle desses fitonematóides é, de maneira geral, tarefa de difícil realização porque cada situação requer cuidadosa análise, antes da definição dos métodos a serem recomendados. No Brasil, as formas comuns de convivência são a rotação de culturas, as variedades resistentes ou tolerantes e o manejo de solo com plantas antagonistas. Para o Estado do Paraná, preconiza-se o manejo de solo, por um período de um e meio a dois anos, visando a redução populacional dos fitonematóides e posterior plantio de café enxertado, como a utilização de Apoatã como cavalo de variedades de Coffea arabica. Neste trabalho, o objetivo foi identificar e mapear as raças fisiológicas de Meloidogyne incognita e a espécie Meloidogyne paranaensis, que infestam lavouras cafeeiras no Estado. Através de coletas por extensionistas da EMATER-PR, um total de 657 amostras de solo e raízes de áreas cafeeiras, com sintomas de Meloidoginose, foi examinado. A presença de Meloidogyne spp. foi constatada em 34,1% das amostras, enquanto 52,5% das amostras apresentaram resultados negativos. Dentre as amostras positivas, 43,8% apresentaram M. paranaensis; 17,41%, a raça 1 de M. incognita; 0,5%, a raça 4 de M. incognita; e 15,6% com Meloidogyne spp. Foram observadas misturas de raças de M. incognita ou com M. paranaensis em 22,8% das amostras.

Due to their potential to cause significant damages and to commit coffee farms, the nematodos of the gender Meloidogyne occupy a prominent position among the pathogens that reduce coffee production. In Paraná, suitable areas for coffee present serious problems with those pathogens. Among the factors that limit coffee cultivation, the nematodes represent the largest concern, due to their difficult control, widespread distribution in the areas and susceptibility of the cultivars. Recently, it was described the species Meloidogyne paranaensis that is thoroughly disseminated in the whole State of Paraná. The movement of coffee seedlings through the coffee areas, allied to the occupation of former coffee areas, create a dynamics in the distribution of the most important species of nematodes that need to be known in order to guide control strategies for the coffee grower. This work aimed at identifying and to map the physiologic races of Meloidogyne incognita and the species M. paranaensis that infest the coffee farms in Paraná, to support research on genetic improvement. These results may also be used to direct the development of door-grafts and resistant cultivars. The coexistence with nematodes demands the soil handling with antagonistic plants for a period of one and a half year to two years, seeking the population reduction, for subsequent introduction of resistant plants. In partnership with EMATER-Paraná, two hundred and ten (210) municipal districts in which coffee is grown were sampled. A total of six hundred and fifty seven (657) soil samples and roots with symptoms of Meloidoginose were collected. Two hundred and twenty four (224) had the occurrence confirmed (34,09%) and three hundred and forty five (345) presented negative results (52,51%). Among the positive samples, ninety eight (98) were conclusive to M. paranaensis (43,75%), thirty nine (39) were M. incognita race 1 (17,41%), one (1) was M. incognita race 4 (0,45%) and Thirty five (35) were Meloidogyne sp. (15,62%). There were fifty one (51) samples with mixture of races of the species M. paranaensis (22,77%).