1Department of Plant pathology, Indian Institute of Horticultural Research, Hasargatta, Bangalore, Karnataka
Directorate of Rice Research, Rajendranagar, Hyderabad, 500030, A.P.
A study was conducted to evaluate four Neem-based formulations in controlling rice blast disease. The in vitro toxicity of test compounds in spore germination studied at 3 concentrations revealed significant reduction in the percentage of spore germination with increase in concentration in Neem-gold, Margocide 20 EC and Repelin RD 9 but were not comparable to Hinosn 50 MC in significantly reducing spore germination. The field performance of the test compounds as post-inoculation spray was evaluated adopting upland micro-plot technique in a randomised replicated trial. The leaf blast severity data indicated that Repelin RD-9 was significantly superior to all other test compounds but was not comparable to effective synthetic blasticides in controlling blast diseases. The less- effectiveness of test compounds could be due to their rapid photodecomposition warranting use of suitable adjuvants in the formulation of these environmentally safe compounds.
