Abstract
Okra (Abelmoschus esculentus (L.) Moench) is one of the important vegetables of the tropical and subtropical areas. In Pakistan okra is cultivated on thousands of hectares but the yield obtained is relatively lower, for which there are many constraints including prevalence of diseases caused by different pathogens. Among various pathogens responsible for the low yield, the root-knot disease incited by Meloidogyne spp., is of considerable economic importance and cause annual losses in tropics to an extent of 22 per cent. As there is meager information regarding the association of root-knot nematodes with okra in the country, the present studies were conducted in 17 districts of the Punjab province of the country to determine the occurrence, prevalence and intensity of root-knot nematodes in okra cultivations in the vegetable growing areas of Punjab. The survey revealed that root-knot nematodes prevailed in 85.28% of okra fields with an average incidence of 38.89%. Hundred per cent prevalence was recorded in Multan, Okara, Dera Ghazi Khan, Bahawalnagar, Vehari, Rahim Yar Khan and Rawalpindi districts and a minimum prevalence of 22.4% was found in Lodhran district. The incidence was above 60% in Bahawalnagar, Rahim Yar Khan, Dera Ghazi Khan and Vehari and was only 4.44% in Lodhran. The severity of infection of the nematodes was highest in Bahawalnagar and Vehari, while it was the lowest in Lodhran. Of the four most common root-knot species, M. incognita constituted 74.74%, M. javanica 24.02%, M. arenaria 1.57% and M. hapla 0.78%.