Management of Root-knot Nematode, Meloidogyne incognita (kofoid & White) Chitwood in Chrysanthemum Using Paecilomyces lilacinus (Thom) Samson in Combination with Neem Cake

Abstract

Talc and pesta granule formulations of P. lilacinus spores, obtained from solid and liquid media, at 12, 10, 8 and 6 per cent moisture levels were evaluated for their spore viability and tbeir field efficacy, singly and in combination with neem cake against root-knot nematode, Meloidogyne incognita in the farmer's field. The preparation of P. lilacinus used in the field consisted mainly of spores. The fungus was cultured under two sets of defined conditions to produce aerial spores, i. e., cultured on sorghum grains, and submerged spores, grown in a liquid medium. Aerial spores were more robust (96, 87, 80 and 60% viability at 6, 8, 10 and 12% moisture levels, respectively, in talc formulation from sorghum grains), compared to submerged spores (83, 72,64 and 54% viability at 6, 8, 10 and 12% moisture levels, respectively, in talc formulation from liquid broth), over a period of 60 days after formulation. Talc and pesta granules of P. lilacinus, applied at 2 doses, 10 and 15 kg/ha to the root-knot nematode infested chrysanthemum field correspondingly reduced root gall index to 1.4-2.7, nematode multiplication rate to 1.4-2.12, and enhanced floral yield by 12 per cent depending on the dose of formulation. Further, combined use of these formulations with neem cake enhanced fungal propagules in rhizosphere to 700-1070, fungal infectivity to 32- 52 per cent and chrysanthemum flower yield (by 23-28 %) depending on the dose of formulation.