Effect of plant extracts about parasites of Meloidogyne incognita (Kofoide & White, 1919) Chitwood, 1949, in cotton

Abstract

The nematode Meloidogyne incognita, race 3 is among the nematodes that cause more damage to the cotton crop, limiting their agricultural productivity. Whereas the use of plants with properties nematicides to control plant parasitic nematode has been much studied as an alternative environmentally acceptable, front to the impacts caused by chemical nematicides, this study has the objective to evaluate the effect of plant extracts obtained from the bark and sheets of Enterolobium contortisiliquum (Tamboril), Astronium fraxinifolium (gonçalo-alves), Hymenaea courbaril ( jatobá) and Mimosa tenuiflora (Jurema) on the nematode parasitism of branch M. incognita in cotton. The extracts were prepared using a 1 g of dry material (sheet or powder of bark) for 10 ml of distilled water and the mixture remained at rest for 24 hours, and thereafter filtered. The experiment was conducted in greenhouse nursery, where every plant of treatment was infested with about 1.000 eggs of M. incognita, remaining for 45 days after infestation. During this period, the applications were made of plant extracts to the ground at the rate of 50 ml for plant. These applications were made every 8 days, the first one carried out 2 days before infestation. Were evaluated the number of galls and eggs by the rootworm of each galls in cotton. The extracts obtained from the sheets and bark of Jatobá and Tamboril were the most efficient, reducing the number of galls on the root system by 65% to 97% compared with the control inoculated. About the number of eggs, no treatment promoted a significant reduction when compared with the control inoculated.