Ravichandra, N. GHARILAL, D. M2017-09-142017-09-142016-07-23TH-11391http://krishikosh.egranth.ac.in/handle/1/5810031118Root-knot nematode (Meloidogyne incognita) is a serious pest of pulse crops and is a major limiting factor in the production of black gram in many parts of the country, including Karnataka. Use of chemicals to manage nematodes affects soil bio-diversity and environment besides their residual toxicity. The present studies were undertaken to survey for the occurrence of root-knot nematode in major pulse growing areas in southern Karnataka districts, screening of available varieties/cultivars of black gram against rootknot nematode and effect of root knot nematode on nodulation, growth and yield parameter in black gram. In the field survey, predominant occurrence of total soil and root population of M. incognita (657/200cc soil and 71/5g of root) followed by Helicotylenchus sp.(70 and 15), Rotylenchulus sp. (30 and 28) and Pratylenchus sp. (22 and 17) were noticed in Chamarajanagar district followed by Tumkuru. Screening of fourteen black gram cultivars viz., 2KU-60, ADT-05, BG-2, DU-1, G-333, IC-282007, IC-436545, K-5-572, KU-8-155, LKU-64, RASHMI, RU10-601, SU-509 and UH-04-04 under glass house condition, revealed that UH-04-04 was more susceptible and G-333 was resistant to M. incognita. M. incognita infection significantly reduced the number of rhizobial nodules, nitrogen content, root length, shoot length, pod number and plant weight. A greater reduction was observed when the M. incognita was established before the inoculation of the Rhizobium than the M. incognita and Rhizobium inoculated together or when the Rhizobium was established before the inoculation of M. incognita.ennullThesis