Measuring severity of root knot nematode (Meloidogyne spp.) on brinjal grown as spring-summer crop at Rampur.

Adhikari H., G. B. KC, S. M. Shrestha and R. B. Thapa. 2007. IAAS Research Advances Vol. 1. Institute of Agriculture and Animal Sciences, Rampur, Chitwan, Nepal. pp. 171-174.

Keywords: Meloidogyne spp, brinjal, root knot nematode

Severity of root knot disease in brinjal grown during spring-summer at Rampur was measured using eight disease parameters through a modified rating scheme developed from data obtained from open field conditions. The scale contained scores from 0-5 for each of the parameters. Number of galls, gall size, egg masses per gram root, juveniles per gram root and per gram soil, root galling percent and root rot scales were obtained from mean values observed in 6 plants per plot out of 20 at 122-140 days after transplanting. Yield reduction percent was estimated from regression of egg mass to fruit yield of brinjal. The scores separated brinjal cultivars in two groups. i.e. moderate and severely affected cultivars. Sum of all the eight parameters to one value gave more contrast division of cultivars and so they could be categorized into low to highly affected one. BE-706 was the most resistant (238.87) while Long Purple was the most susceptible (400.22) cultivar when grown during spring-summer at Rampur. BE-706 had the lowest number of egg masses per gram root, the lowest yield reduction percent and lower to moderate values in most of the disease parameters, and so was the most resistant against root knot nematodes. All other cultivars had moderate to high disease scores and they were ranked more susceptible during that season.