Wheat Disinfestation Using Microwave Energy

Abstract

Disinfestation of grains using microwaves can be an alternative method to pesticidesin killing insects. A method to control insects in grains using microwave energy is described inthis manuscript. An industrial microwave system operating at 2.45 GHz was used in this study todetermine the mortality of three common types of stored-grain insects namely Triboliumcastaneum (Herbst), Cryptolestes ferrugineus (Stephens) and Sitophilus granarius (L.). Wheatsamples of 50 g each at 16% moisture content (wet basis) were infested with 5, 10 and 15 adultinsects. The infested samples were then exposed to microwaves at four different power levels of0.25, 0.3, 0.4 and 0.5 kW/kg for two exposure times of 28 and 56 s. A 100% mortality wasachieved for T. castaneum adults at 0.5 kW/kg power level for both exposure times of 28 and56 s. The mortality rates were lower at the lower power levels. For instance, at 0.25, 0.3 and0.4 kW/kg power levels, the mortality rates were 45, 58 and 85%, respectively. Similar resultswere obtained for the other two insects. Germination tests were conducted for different samplesand it was determined that the germination of wheat kernels that were treated with microwaveenergy was lowered.