Reaction of Pigeonpea Cultivars and Germplasm Accessions to the Root-knot Nematode, Meloidogyne javanica.

Meloidogyne javanica is an important nematode pest of pigeonpea. Thirty-four pigeonpea cultivars and 227 germplasm accessions were evaluated for resistance to M. javanica based on number of galls, egg masses, size of galls, and area of root covered with galls. Galls were not formed on 75% of the cultivars, and no egg masses were observed on the roots of four cultivars (UPAS 120, Pant A3, CO 1, and BDN 2); however, shoot 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 nematode-infested soil. Cultivars with low gall and egg mass ratings and significantly reduced vegetative biomass in nematode-infested soil were considered to have low tolerance to the nematode. Galls and egg masses were found on all the germplasm accessions; galls were usually more common than egg masses. None of the germplasm accessions were resistant to M. javanica, but 33 accessions were moderately resistant. Large variations in gall number, gall size, and egg mass number were observed. ICP 24 and ICP 99, two moderately resistant accessions, manifested low plant-to-plant variation.