Hatching and mortality of second-stage juveniles of Meloidogyne incognita race 2 in essential plant oils

Abstract

The nematodes of the genus Meloidogyne seriously affect the production of various cultures throughout the world. The search for alternative control of the pathogen with natural products is well advanced, however, is essential the scientific proof of nematicidal activity of them for their validation as efficient method of control. So it became objective of this research, in vitro, the effect of essential oils of six medicinal species (Ocimum gratissimum, Lippia alba, L. sidoides, Cymbopogon citratus, C. winterianus, and Eucaliptus terenticornis) in seven concentrations (0; 0.3125; 0.0625; 1.25; 2.5; 5.0 and 10.0 ml L^-1) on the outbreak the hatching of mortality second-stage juveniles (J2) of M. incognita race 2. With this purpose at the Laboratory of Phitopathology, CCA/UFC, was done a trial in a factorial arrangement 6 x 7, prepared in a completely randomized design, using 42 treatments with six repetitions consisting of 60 eggs each. Were used eggs extracted from nematode infested roots of “Santa Clara” tomato plants, incubating them in Petri dishes of acrylic of 3.5 cm in diameter, at room temperature (27±3 °C). The ratings started at 24 hours after mounting the test, extending up to 16 days, with the counting of J2 and hatched, or killed in intervals of 48 hours. It appeared that all essential oils affected the outbreak or the survival of J2 at concentrations of 5.0 and 10.0 ml L^-1. However, at higher dilutions < 1.25 ml L^-1, only the oils of L. sidoides and C. winterianus had nematostatic and nematicidal activity, thus, considered promising for tests at green-house for control plant parasitic nematode in the ground.