Incidence and Reproduction of Meloidogyne incognita on Vegetable Crop Genotypes

Abstract

In 2006-2008, a survey was conducted in 16 major vegetable production areas of the Punjab with the purpose of determining the incidence and distribution of Meloidogyne incognita and its reproduction on vegetable crop genotypes in nematode infested fields and in the green house. Two root knot nematode species. M. incognita and M. javanica, were identified from 260 samples. Meloidogyne incognita was the predominantly found species and was detected in 13.6% of all the fields surveyed. In the field, the average nematode incidence was 41.5% and ranged from 5.4% in fields planted with mustard to 94.4% in fields planted with okra. The root gall severity averaged 5.5 on scale of 0 to 9. Seventeen vegetable genotypes were evaluated for resistance to gall formation and reproduction by M. incognita. Resistance was identified only in cauliflower, mustard, and radish. The most susceptible genotypes were bitter gourd, carrot, cucumber, eggplant, lettuce, okra, pea, pumpkin, sponge gourd and watermelon meanwhile; three plant species cabbage, chilies, and coriander provided an intermediate host response. Some plant genotypes appeared to be hypersensitive as they exhibited heavy root galling but suppressed nematode reproduction. These included members of family Cucurbitaceae.