The Efficacy of natural plant extracts in controlling rice weevil (Sitophilus oryzae)

Abstract

Rice weevil (Sitophilus oryzae) is one of the significant pests & has caused serious damage in rice storage. The use of synthetic pesticides to control them has had negative effect on environment, animal & human. In order to this issue, natural plant extract based pest control alternative were analysis. This study aimed to evaluate the efficacy of natural plant extract; Neem leaves (Azadirachta indica) & Eucalyptus leaves (Eucalyptus globules) & mixture of neem leaves powder & eucalyptus oil in tablet form in controlling rice weevil (Sitophilus oryzae). The experimental treatment consist of control (T0) where no plant extract applied, (T1) Neem leaves, (T2) Eucalyptus leaves & (T3) combination of neem leaves powder & eucalyptus oil in tablet form. Each treatment was regulate with 20g dose to 100g of rice, that had 20 weevil added & mortality was assessed after 6,12,18, 24, 30, 36 days. The result showed that (T3) mixture of neem leaves powder & eucalyptus oil in tablet form was found to more effective overall than the other treatment (86.50%) mortality at 36 days after treatment. When compared to other treatment, followed by (T1) Neem leaves (78.72%) mortality whereas (T2) Eucalyptus leaves were found less effective (66.30%) mortality. So natural plants extract treatment (T3) was found highly effective in controlling rice weevil & reduction in grain damage over than the other treatment. The order of effectiveness of botanicals is ranked as Mixture of neem powder & eucalyptus oil in tablet form>Neem leaves>Eucalyptus leaves respectively. Finally, it was concluded that natural plant extract could be used for protection of stored rice & serve as alternative method to synthetic insecticides in controlling Sitophilus oryzae infesting rice.