Rice weevil management through application of silica nano particle and physico-chemical and cooking characterization of the treated rice

Abstract

Nano technology is an alternative method for pest management and can be applied to minimize the post harvest storage losses due to insect infestation. A study was undertaken with an aim to control the stored grain pests, particularly rice weevil using silica nano particle (SNP). The nano-silica of 30 nm size was taken for the experiment. Entomotoxic effect of five different doses of SNP was tested against rice weevil Sitophilus oryzae. The effects of SNP mixing with grain at the rate of 0.25, 0.5, 0.75 and 1.0 g/kg of rice, stored in glass jars and gunny bags were examined. The cumulative mortality rate was studied at 1, 2, 4, 7 and14 days of exposure. Mortality rate of 80 and 97.4% were achieved after 7 and 14 days of storage by application of SNP at the rate of 0.5 g per kg of rice. Residual persistency of samples treated with optimum dose of SNP was studied by washing with distilled water at the ratio of 1:2 (sample to water ratio) for three times and the samples were studied under Scanning Electron Microscope (SEM). Single washing prior to cooking was found to be sufficient enough for removing the SNP from treated rice and can be recommended safe for cooking and consumption. This process can also prove to be an eco-friendly and efficient pest management technology. The technology is suitable for industrial application in large scale warehouses and storage godowns to control stored grain insect pests.