Nematocidal activity of fermented extracts from Lantana camara plant parts against Meloidogyne javanica on tomato

Abstract

ABSTRACT Root-knot nematode (Meloidogyne sp.) is a major concern due to difficulty of control. Secondary metabolites naturally occurring in plants offer a method for combating invasion by root-knot nematode . The study was conducted to investigate nematocidal effects of plant parts of fermented Lantana camara L. collected around the Visage, George and Mooketsi areas, Limpopo Province, South Africa. Effective dosages of plant extracts, which could be applied through a drip irrigation system, on tomato (Solanum lycopersicum L) were determined against nematode infection. Extracts of L. camara were evaluated at aqueous concentrations of 0.92%, 2.76%, or 3.68% (v/v) for effects on plant parameters. Mortality rate of Meloidogyne javanica J2 treated with fermented Lantana camara at varying extract concentration, location and tissue was significant. Nematocidal activity of the extracts were mainly due to plant part and concentration. There was a significant location × tissue interaction for wet plant biomass, Meloidogyne javanica galling index, root egg mass, and soil egg mass. The reduction in final nematode population, root-knot index and soil egg hatching after 8 weeks following transplanting in pot trials is indicative of nematocidal activity of L. camara. There was no difference in location × tissue interaction for plant height, stem diameter, and number of fruit. Treatment with fermented L. camara was not phytotoxic. Fermented L. camara plant extracts may be used for management of root-knot nematode in tomato, but this must be validated in field trials.