Atividade nematicida de diferentes concentrações de extratos vegetais de canola sobre Meloidogyne spp.

Abstract

Tomato is among the most produced vegetables in the country, consequently, monoculture, causes more plant diseases to appear, reducing production and often even causing producers to abandon their production. The gall nematode is among the major diseases affecting the crop, reducing its production, causing damage, often immeasurable to the producers. As has been indicated is the management, involving crop rotation, use of resistant species, care of infested machinery and application of chemical, biological or alternative products. In this context, alternative products from Brassicas, among them canola (Brassica napus), have been widely researched, because they are composed of chemical substances that have a nematicidal effect, originating from their secondary metabolism. Therefore, the objective of this work was to carry out applications of aqueous extracts of aerial part and root of canola, in different concentrations and forms of application, in tomato plants infected with Meloidogyne javanica, M. incognita and M. arenaria, in vitro and in vivo, as well as the phytochemical analysis of plant extracts. The in vitro experiment was carried out in Elisa type microtiter plates, with evaluation of juveniles and eggs of the three species, tested against extracts of shoot and root, at concentrations of 0%, 10%, 15% and 20% , in a completely randomized design with four replicates. Mortality, juvenile hatching and phytochemical analysis of the two extracts were analyzed. The in vivo experiment was repeated, where soil application and spraying and soil application of aqueous extracts of root and shoot of canola plants at concentrations of 0%, 10%, 15% and 20% were tested on plants of tomatoes infected with 5000 eggs + J2, from M. javanica, M. incognita and M. arenaria, individually. The design was completely randomized, in a 2x2x4 factorial scheme (application forms x type of extract x concentration), with six replications. After 60 days were analyzed, number of galls, reproduction factor, shoot height (cm), shoot mass (g), root mass. In the in vitro experiment, both aqueous extracts of canola caused interference in both hatching and mortality, from the concentration of 10% inhibiting them at the concentration of 20%. According to the phytochemical analysis the secondary compounds present in the extracts were: saponins, alkaloids, flavonoids, terpenes and tannins. In the in vivo experiment, the results were similar to the in vitro test, where both aqueous extracts of canola showed a nematicidal effect, reducing the reproductive factor and the number of galls of the three nematode species tested, as well as increasing plant development of tomato from the concentration of 10%, regardless of the application forms. It is concluded that the canola extract can be considered as potential for the alternative control of the gall nematode, mainly because they have bioactive compounds with nematicidal and / or nematodetic properties.