Antagonistic effect of Steinernema abbasi and Heterorhabditis indica Philippine isolates on root penetration and development of Meloidogyne incognita in tomato

Abstract

ABSTRACT The antagonistic activity of four Philippine EPN isolates of Steinernema abbasi Elawad et al. (SaMBLB) and Heterorhabditis indica Poinar et al., (HiPBCB, HiBSDS, and HiMAP) was investigated against Meloidogyne incognita (Kofoid & White) Chitwood. Fourteen days after inoculation, it was demonstrated that concomitant application of 1,000 live infective juveniles (IJ) of each EPN species and 200 M. incognita IJ significantly reduced root penetration consequently affecting juvenile development to the adult stage of M. incognita. The lowest number of M. incognita was found in plants treated with S. abbasi MBLB (1.90 ± 2.20) and H. indica PBCB (2.05 ± 2.61). Externally, formation of well-developed galls was only observed on tomato plants inoculated with RKN alone indicative of the negative effect of EPN to M. incognita root penetration. However, none of the EPN isolates had positive effect on the growth of M. incognita-treated tomato plants measured through plant height. This study provides the first insight on the biological control potential of these local EPN isolates for the management of M. incognita in the Philippines.