REACTION OF PIGEONPEA CULTIVARS AND GERMPLASM ACCESSIONS TO THE ROOT-KNOT NEMATODE, MELOIDOGYNE-JAVANICA

Meloidogyne javanica is an important nematode pest of pigeonpea. Thirt y-four pigeonpea cultivars and 227 germplasm accessions were evaluated for resistance to M. javanica based on number of galls, egg masses, s ize of galls, and area of root covered with galls. Galls were not form ed on 75% of the cultivars, and no egg masses were observed on the roo ts of four cultivars (UPAS 120, Pant A3, CO 1, and BDN 2); however, sh oot mass of 64% of the cultivars was reduced by M. javanica. Pant A3, ANM 504, and BDN 2 were identified as highly resistant to M. javanica. Plant weight of these cultivars was not reduced (P = 0.05) in the nem atode-infested soil. Cultivars with low gall and egg mass ratings and significantly reduced vegetative biomass in nematode-infested soil wer e considered to have low tolerance to the nematode. Galls and egg mass es were found on all the germplasm accessions; galls were usually more common than egg masses. None of the germplasm accessions were resista nt to M. javanica, but 33 accessions were moderately resistant. Large variations in gall number, gall size, and egg mass number were observe d. ICP 24 and ICP 99, two moderately resistant accessions, manifested low plant-to-plant variation.