Biocontrol Potential of Optimized Culture Filtrates of Streptomyces fradiae Against Root Knot Nematode Meloidogyne incognita in Tomato

A study was conducted to evaluate the biocontrol potential of the optimized culture filtrates of Streptomyces fradiae against root-knot nematode Meloidogyne incognita in tomato under field conditions. The fermentation medium of S. fradiae optimized with pH 6 at 35oC with starch and yeast extract as carbon and nitrogen sources respectively maximized the colonization rate of S. fradiae. The culture filtrate of the optimized medium of S. fradiae caused in higher degree of inhibition in egg hatching, and mortality of juveniles of M. incognita. The effectiveness caused medium of S. fradiae against M .incognita was related to higher production of secondary metabolites subsequent to maximization of colonization. The S. fradiae experimented for the management of M. incognita under field conditions revealed its effectiveness for the suppression of nematode population and reduced the severity of nematode disease in terms of gall index. The suppression in M. incognita population / incidence following application of S. fradiae resulted in significant improvement in yield attributes including fruit yield of tomato.