Relative Efficacy of Plant Products as Grain Protectant against Sitophilus oryzae (Linn.) in Stored Maize Grains

Abstract

The efficacy of four plant products viz., black pepper powder, neem leaf powder, garlic clove powder and onion bulb powder @ 1, 3 and 5 g/100 g grains of maize was tested as grain protectant against Sitophilus oryzae (Linn.) in laboratory during 2007-08 at Department of Entomology, Rajasthan College of Agriculture, Udaipur. Black pepper powder @ 5% was found most effective causing highest adult mortality (63.33%) when released in freshly treated maize grains, lowest grain damage (10.10%), weight loss (5.00%) and adult emergence (60.00 adults). High adult mortality and low grain damage, weight loss and adult emergence was observed at the beginning, but mortality gradually declined and grain damage, weight loss and adult emergence increased as the duration of treatment increased from fresh to 21 days. Onion bulb powder 1% was found least effective by giving minimum adult mortality (11.67%), maximum grain damage (28.54%), weight loss (13.27%) and adult emergence (315.00 adults). The germination of maize grains was not significantly affected due to the treatments of different plant products up to 120 days of treatment. Key words: Sitophilus oryzae, plant products, efficacy, maize, grain protectant.