Efficacy of plant products against bruchid, Spermophagus tessellatus infesting mesta seed in storage

Laboratory studies on the efficacy of certain plant products (powders and oils) against mesta bruchid, Spermophagus tessellatus Met. in stored mesta seed were conducted during 2007–2010 at Agricultural Research Station, Amadalavalasa. Among the powders and oils, sweetflag rhizome powder@ 10g/kg seed and citronella oil@ 5ml/1 were found to be effective by recording cent percent mortality of the bruchids and zero percent seed damage and also there was no detrimental effect of these powders and oils on germination of mesta seed. Similar trend of efficacy was observed in the standard check methyl parathion @ 3g/kg seed. These treatments were on par with each other. The persistent toxicity of the rhizome powder and oil continued upto three months. Whereas, untreated check recorded highest seed damage and highest population of the bruchids.