Management of Meloidogyne javanica on tomato using agro-industrial wastes

Nematodes of the genus Meloidogyne are one of the major limiting factors in tomato production and a challenging problem in organic systems. This study aimed to investigate the effect of agro-industrial wastes, their forms of application and doses on tomato plants inoculated with Meloidogyne javanica. First, nematodes were multiplied on tomato under glasshouse conditions to simulate a naturally infested environment. At 60 days after inoculation, plant shoots were removed, new seedlings were transplanted into the pots, and the soil was amended with agro-industrial wastes. Treatments were as follows: rice husk, common bean hull, soybean hull, orange bagasse, poultry litter and waste mixture (wastes mixed in equal proportions) applied in three different forms (raw, powdered and biodigester effluent). A non-treated control and a composted waste mixture were also assessed. At 60 days after transplanting, plants were evaluated for nematode parameters. Powdered bean hulls, soybean hulls, orange bagasse and waste mixture provided the best results and were selected for dose-response investigations. A second experiment was conducted in two periods using, in addition to the selected wastes, a mixture of powdered bean hulls, soybean hulls and orange bagasse. Wastes were applied at doses of 0 (control), 2, 4, 6 and 8 t ha(-1). Powdered bean hulls, soybean hulls, orange bagasse and waste mixtures at 5 t ha(-1) gave the best nematode control, with reductions of 55-100%. The optimal doses for vegetative growth were 4 t ha(-1) in the first period and 5 t ha(-1) in the second period.