Management of Meloidogyne exigua in rubber trees with biological and chemical products

ABSTRACT To better understand the management of Meloidogyne exigua in rubber trees, two control methods for rubber tree decline, chemical and biological methods, were tested in the field. Thus, the present study evaluated the response of six treatments: T1 – Control, T2 – Paecilomyces lilacinus + Trichoderma harzianum (300 g ha-1 each), T3 – Trichoderma asperelloides (1 g L-1) + Bacillus subtilis (1 mL L-1) + Bacillus methylotrophicus (2 mL L-1), T4 – Cadusafos (15 L ha-1), T5 – Bacillus subtilis + Bacillus licheniformis (1.0 to 1.5 kg ha-1) and T6 – Fluensulfone (3 L ha-1) and their potential action on nematodes. In addition, a possible increase in latex production due to treatments was studied, as well as a possible relationship between infestation and diameter increment in rubber trees. The experiment was conducted in a farm located in the region of “Triângulo Mineiro”, Minas Gerais State. The study was established in a randomized block design, with six treatments and five replicates. Four samplings were performed to determine nematode population density in pre and post-applications up to 30 days after the last application. The samples were stored in plastic bags and taken to the Nematology Laboratory at Federal University of Uberlândia for analysis. Reproduction factor, latex yield and mean diameter of the trees were evaluated. T5 and T2 reduced the reproduction factor, compared to the other treatments. None of the evaluated products demonstrated efficacy for the productivity characteristics: kg ha-1, kg tree-1 and kg plot-1, suggesting that recommendation of the products is not justifiable yet for this characteristic. Mean diameters of plots were not influenced by the used treatments either.