BIOATIVIDADE DE EXTRATOS DE NIM (Azadirachta indica) E RUBIM (Leonurus sibiricus) SOBRE Meloidogyne javanica IN VITRO

Abstract

Meloidogyne javanica is one of the most common phytoparasite nematode species and that causes more damage to world agriculture, including Brazilian agriculture. Its management is very difficult, once it contaminates previously considered free areas, because it can survive for long periods in the soil. Thus, new control methods must be developed for the management of this nematode. The objective of this work was to evaluate the effect of the aqueous extract of neem (Azadirachta indica) and honeyweed (Leonurus sibiricus) on juvenile mortality and egg hatching of M. javanica in vitro. The experiment was installed and conducted under laboratory conditions. The treatments were 5%, 10%, 15%, 20%, 25% (w / v) of the aqueous extract of leaves of A. indica and L. sibiricus, plus the negative control containing only distilled water, both for evaluation juvenile mortality (J2), and for J2 hatching. Neem and honeyweed extracts had a significant effect on juvenile mortality of M. as well as on J2 hatch reduction. In the case of the use of neem, the in vitro mortality of M. javanica was increasing according to the increase in the concentration in the aqueous extract. Concentrations 10, 15, 20 and 25% were the ones that most reduced the percentage of mortality. The extract of 25% of neem reduced 60% of the mortality compared to the negative control. Regarding honeyweed, all treatments also differed statistically from the negative control, and the concentration at 25% promoted higher mortality levels, reducing the percentage of mortality by more than 60% compared to the negative control. Both extracts inhibited the hatching of juveniles of M. javanica. The concentration of neem at 25% promoted the highest inhibition of hatching, of J2 of the order 78% more compared to the negative control. The same behavior was observed when the honeyweed aqueous extract was used. For Nim, it is recommended to use the extract at a concentration of 10% to promote higher levels of juvenile mortality and from 20% for drastic reduction in hatching eggs, and for honeyweed the concentration from 20% for larger levels of juvenile mortality and greater reduction in hatching of M. javanica eggs.