Bioefficacy of spore suspensions and mass culture of Dactylaria brochopaga on Meloidogyne incognita (kofoid and white) chitwood causing root-knot disease of tomato (Lycopersicon esculentum Mill.)

Abstract

An experiment was conducted in the laboratory to study the induction of predatory rings and predacity test of isolates of Dactylaria brochopaga against second stage juveniles (J2s) of Meloidogyne incognita. Another experiment was also conducted in pots to study the effect of D. brochopaga (isolate D) on the management of root-knot disease of tomato. Isolate D of D. brochopaga showed maximum induction of predatory rings and in turn, trapped maximum number of second stage juveniles (J2s) of M. incognita in duel culture in laboratory test. For pot experiments, the promising isolate D among five isolates of D. brochopaga was grown on sorghum grains for its mass culture. The bioefficacy of spore suspensions and mass culture of D. brochopaga (isolate D) was studied with and without Cow Dung Manure (CDM) on root-knot, population of M. incognita and growth of tomato plants. The application of mass culture at 1%, its undiluted and diluted (10 times) spore suspension in soil infested with 1500 juveniles of M. incognita per 1000 g before planting of tomato seedlings, increased the plants growth and reduced the number of root-knots by 28.69-55.36%, of females by 25.52-49.41%, of egg masses by 20.53-54.40% and of juveniles by 30.61-54.83% in pot experiments. The bioefficacy of the fungus as nematode antagonist was enhanced when its spore suspensions and mass culture were applied with CDM which reduced the number of root-knots by 49.27-75.36%, of females by 38.87-69.32%, of egg masses by 47.04-77.20% and of juveniles by 51.87-76.09%. Furthermore, spore suspensions of the fungus also enhanced the growth of tomato plants and reduced the population of M. incognita significantly. © 2011 Academic Journals Inc.