CHARACTERIZATION OF SUSCEPTIBILITY AND RESISTANCE RESPONSES TO ROOT-KNOT NEMATODE (Meloidogyne incognita) INFECTION IN OKRA GERMPLASM

Twelve okra (Abelmoschus esculentus L.) cultivars were evaluated for their characterization of susceptibility and resistance responses to root-knot nematode (Meloidogyne incognita). Plants of test okra cultivars were inoculated with 3000 freshly hatched second stage juveniles of M. incognita. The nematode caused reductions in various growth parameters of all the cultivars to varying levels over their respective controls. None of the cultivars was found immune, highly resistant or resistant. The cultivar ‘Sharmeeli’ was found to be highly susceptible as maximum galls ( 100) were recorded on the roots of this cultivar. The cultivar also showed maximum reductions in growth parameters. The cultivars Anmol and Okra Sindha were found to be susceptible (71-100 galls). In the same way, the cultivars Sabz Pari, Super Star, PMS-55 and PMS Beauty appeared as moderately susceptible (31-70 galls) and reductions in growth parameters of these cultivars were comparatively less severe as compared to those observed in the case of susceptible and highly susceptible cultivars. Five cultivars viz. Sanam, Dikshah, Arka Anamika, Ikra-1 and Ikra-2 (11-30 galls) were rated as moderately resistant as these cultivars showed less damage by the nematode as compared to susceptible and moderately and highly susceptible cultivars and their use could provide a useful tool to control root-knot nematodes.