Manejo de Meloidogyne exigua em seringueira com produtos biológicos e químicos

Abstract

Brazil held the position of the greatest rubber producer and exporter of the world for many years. After the second half of the past century, such reality changed and the country became an importer, mostly from southeastern Asia. Great attention must be given to phytosanitary problems, which can contribute for production reduction, for the proper management of a rubber tree orchard. Little attention has been given to nematodes, despite reported damages in function of attack by Meloidogyne exigua. Nematode control in the soil can be done by different methods, with emphasis to chemical and biological methods. This study evaluated biological and chemical products for field management of Rubber Tree Descending Death and the reduction of M. exigua population density, it also evaluated if there is a relation between infestation and diameter increment of the trees. The experiment was done in a farm located in the Triângulo Mineiro, MG. The products Nemat + Ecotrich (300 g ha-1each); Nemix (1.0 to 1.5 kg ha-¹); GF 422 (1 g L-1) + Onyx (1 mL L-1) and Rizos (2 mL L-1) (first application: GF 422 + Onyx; second application: GF 422 + Rizos; third application: GF 422 + Onyx); Rugby (Cadusaphos, 15 L ha-1) and Nimitz (Fluensulfone, 3 L ha-¹) were evaluated, besides a non-sprayed control. The experimental design was randomized blocks, with six treatments and five replications. Four samplings were done to determine nematode population density before and after each application. The samples were placed in plastic bags and taken to the Laboratório de Nematologia of Universidade Federal de Uberlândia for processing. Reproduction factor, latex productivity and tree average diameter were evaluated. Among all treatments evaluated, Nimitz and Nemix reduced the reproduction factor in relation to the others. None of the products was effective for the three yield characteristics evaluated: production per hectare, production per tree and production per plot, indicating that their recommendation for these characteristics is not justified yet. The average tree diameter was not affected by any of the treatments evaluated.