Suppression of root-knot nematodes in tomato and cucumber using biological control agents

Abstract

Antagonistic fungi are continuously attracting a lot of attention as alternatives to chemical control of root-knot nematodes. The egg-pathogenic fungus Paecilomyces lilacinus, particularly strain 251 has shown promising potential as a biological control agent against various plant-parasitic nematodes. Strain 251 of P. lilacinus (PL251) and Arthrobotrys conoides (Melodogone) were tested for their efficacy against Meloidogyne spp. in tomato and cucumber under greenhouse conditions. The study aimed at determining the application rates and timing of application of the fungi. Both pre-planting and at planting application of PL251 were found to reduce nematode populations and root galling in both tomato and cucumber. Pre-planting soil treatment (0.4g/10 L of soil) reduced final nematode populations by 69% and 73% in the roots and soil, respectively, compared to the non-inoculated control in tomato. However, soil treatment at planting recorded reduction level of 54% and 74% in the roots and soil, respectively. Use of A. conoides showed lower nematode control in cucumber. Only 28% and 21% reduction levels were recorded in the roots and soil when the fungus was applied at planting, respectively. This study has demonstrated that PL251 has a promising potential that could be exploited in the management of Meloidogyne spp. in vegetable production systems.