ECO-FRIENDLY MANAGEMENT OF RICE WEEVIL,SITOPHILUS ORYZAELINN. USING SOME BOTANICALS AND FUMIGANTS ON STORED RICE

Abstract

Two experiments were conducted in the laboratory under the Department of Entomology, Sher-e-Bangla Agricultural University, Dhaka, Bangladesh during the period from September 2011 to February 2012 to find out the efficacy of some promising botanicals and fumigants applied against rice weevil, Sitophilus oryzae Linn. on stored rice. Under experiment where five botanicals along with one untreated control were used viz. dried neem leaf powder @ 2.5 g/kg rice, dried bishkatali leaf powder @ 2.5 g/kg rice, dried marigold leaf powder @ 2.5 g/kg rice, dried dholkolmi leaf powder @ 2.5 g/kg rice, dried mahogany leaf powder @ 2.5 g/kg rice, and untreated control. In experiment three fumigants along with untreated control treatments were used viz. camphor @ 1 gm/kg rice, phostoxin tablet @ 200 mg/kg rice, naphthalene @ 500 mg/kg rice and untreated control. Both the experiments were laid out in Completely Randomized Design (CRD) with 4 replications. Among five botanicals, the dried neem leaf powder @ 2.5 gm/kg rice reduced the highest percent of grain infestation by number (65.81%) and weight (57.42%) over control during the management of rice weevil, S. oryzae in storage than dried leaf powder of bishkatali, marigold, dholkalmi and mahogany; whereas, the dried mahogany leaf powder reduced showed the least performance in reducing the percent grain infestation by number (32.14% and weight (26.76%) over control. Among three fumigants, camphor @ 1 gm/kg rice reduced the highest percent ofgrain infestation by number (73.34%) and weight (76.19%) over control than phostoxin tablet and naphthalene, where naphthalene @ 500 mg/kg rice reduced the lowest percent of grain infestation by number (55.15%) and weight (59.96%) over control. Irrespective of botanicals and fumigant based management practices, all fumigants performed superior in terms of the reduction of percent grain infestation and survibility of larvae and pupae of rice weevil than botanicals, where camphor @ 1.0 gm/kg rice grains showed the best performance in controlling rice weevil on rice in storage. Camphor is also acceptable for the consumers in terms of environmental safety point and human health hazards free measures applied against insect pests of stored products, because it is derived from Cinnamonum camphora plant.