Effect of Meloidogyne javanica and Fusarium udum Singly and Concomitantly on Wilt Resistant Accessions of Pigeonpea

An experiment was conducted to assess the damage caused by root-knot nematode Meloidogyne javanica to five wilt resistant accessions of pigeonpea viz. DPPA 85–14, DPPA 85-5, Banda Palera, Sujata and DPPA 85–11. All the accessions were found susceptible to nematode infection. Banda Palera and Sujata supported fewer nematodes. Presence of root-knot nematode M. javanica with F. udum applied to the roots of pigeonpea seedlings caused a susceptible reaction to fusarium wilt in all the accessions used in the study. Wilt severity was highest in DPPA 8514 (46.66%) and it was followed by DPPA 85–11 (40.0%), DPPA 85-5 (35.55%), Sujata (25.71%) and Banda Palera (22.85%). Fungus alone caused least affect on wilting of plants. When nematode was used alone, greatest number of root galls (34–48 galls) and egg masses (41–45) developed on the accessions Sujata, DPPA 85–11, DPPA 85-5 and DPPA 85–14 and the least (29 galls and 38 egg masses/root system) on Banda Palera. However, in the presence of both the organisms i.e., nematode and fungus, the development of root galls and egg masses was less as compared to nematode alone. Soil population of nematode increased when the nematode was applied alone but the presence of fungus caused a suppressive effect on nematode population. Plant growth characters such as fresh and dry shoot-root weight and formation of rhizobial nodules on roots were affected in all the pigeonpea accessions when M. javanica was associated with F. udum. Greatest suppression in rhizobial nodulation (47.36%) was observed in DPPA 85–14 and it was followed by DPPA 85–11 (46.29%), DPPA 85-5 (37.50), Sujata (35.08) and Banda Palera (31.66). Greatest reduction in growth parameters was observed when plants were inoculated with M. javanica and F. udum simultaneously and it was followed by M. javanica prior to F. udum and F. udum prior to M. javanica, respectively.