Efficacy of Aktrine 4.6 SL (matrine) for the control of major insect pests of rice

Abstract

Aktrine 4.6 SL is a matrine, which is a natural derivative extracted from the leaves and roots of shrubby sophora (Sophora flavescens). This study was conducted to determine the efficiency of Aktrine 4.6 SL as a biological control agent against rice black bugs (RBB) (Scotinophara coarctata Fabricus), rice bugs (Leptocorisa acuta Thunberg), and white stem borers (Scirpophaga innotata Walker). Three Aktrine 4.6 SL concentrations were used in this study: 0.5 mL∙L^–1, 1.0 mL·L^–1, and 2.0 mL∙L^–1. Pure water treatment served as the control. The experiment was set in Randomized Complete Block Design (RCBD) with four treatments, replicated four times on the populations of the three species. Results demonstrate that Aktrine 4.6 SL applied at 1.0 and 2.0 ml∙L^–1 can control pest infestation and damage. At these concentrations, rice black bug and rice bug populations as well as damage from stem borer were significantly lower compared to plants with no treatment or those applied with 0.5 ml∙L^–1 Aktrine 4.6 SL. Further, plots treated with 1.0 and 2.0 ml∙L^–1 concentrations of Aktrine 4.6 SL produced significantly higher grain yield. To minimize costs, a concentration of 1.0 ml·L–1 is recommended.