BIOFUMIGAÇÃO ASSOCIADA À SOLARIZAÇÃO NO CONTROLE DE Meloidogyne incognita EM ALFACE

Abstract

The lettuce (Lactuca sativa) is nationally the most important leaf vegetables. However, it’s cultivation is influenced by the incidence of pathogens, like the nematodes, mainly those of the genus Meloidogyne spp. Nowadays, techniques that are not aggressive for the environment and that prefer the organic cultivation of the vegetables, have been developed. Between among the strategies for the control of these phytonematodes, are the biofumigation and the solarization. Therefore, the objective of the present study was the assessment of the efficacy of the biofumigation with residues of kale and cabbage with association or not with solarization for the control of M. incognita in lettuce cultivation. The experiments were conducted entirely in randomized factorial scheme 2x3+1 with four repetitions. The first factor was the presence or absence of soil solarization, with transparent polyethylene plastic of 150 µ thickness and the second was the biofumigation with kale residues (Brassica oleracea var. acephala), cabbage (Brassica oleracea var. capitata), or the absence of residues. The addicional factor was the application of microbiological nematicide NEMAT® (Paecilomyces lilacinus). The experimental part consisted in a three liters bowl containing a ‘Vera’ lettuce. Initially, tomato plants were used for the establishment of the inicial population of M. incognita on the soil. In the treatments that were submitted to solarization and biofumigation, the fresh matter was incorpored into the soil and to the covered bowl for 30 days with the transparent polyethylene plastic. For the biofumigation process only, the fresh materia of cabbage or kale, according to the treatment, was incorpored to the soil seven days before the transplant of lettuce seedings. After the application of the treatments, ‘Vera’ lettuce seedings were transplanted into bowls containing the treated soil, and conducted for 55 days. The following were evaluated: fresh mass off the aerial part and the root, number of eggs and nematodes on the roots, number of nematodes in 200 cm² of the soil. The incorporation of brassicas residues enabled a better development of the lettuce plants, with increments of the fresh mass of the roots and the aerial part. In addition to that, the population of M. incognita on the soil, in the treatments submitted to biofumigation with cabbage, regardless of the use of solarization, such as that with only solarization and the standart witness with the microbiologic nematicide were able to annul the number of nematodes on the soil. The treatments with the presence of kale residues, with the use or not of solarization, were able to reduce the number of nematodes. We concluded that the association of techniques of biofumigation with brássicas and the solarization in the conditions that the experiment was conducted was efficient as a strategie of M. incognita.