Nematodes Associated to Tropical Forages in Pasture Areas

Abstract

The quantification of soil nematodes is of great importance for the management and evaluation of the efficiency of control methods, considering the damages caused in crops of economic interest. The present work aimed to quantify and identify plant parasitic nematodes in pasture areas in the municipality of Santo Antônio do Leverger, Mato Grosso state, Brazil. For that purpose, 25 soil and root samples were collected in four plots, consisting of the following forage grasses: Brachiaria humidicola cv. Common (Plot 1), Panicum maximum cv. Tanzania (Plot 2), Brachiaria brizantha cv. Marandu (Plot 3) and Panicum maximum cv. Massai (Plot 4). The nematode extraction from the soil and root samples was performed, followed by the quantification and identification of nematodes genera. The nematodes classified as free-living were observed in all plots, with population densities varying from 230 to 1180 specimens. The genus Pratylenchus presented the lowest population level, with 40 specimens, in the area where the Brachiaria humidicola cv. Common is cultivated. The following phytoparasitic nematodes genera were observed: Pratylenchus and Paratrichodorus associated to the Humidicola grass, and Heterodera and Criconemoides associated to the Tanzania grass.