Influence of solvent medium on the bioefficacy of ten plant materials against adult African rice gall midge (AfRGM-Orseolia oryzivora)

Abstract

A study conducted at Africa Rice Center, International Institute for Tropical Agriculture, Ibadan, Nigeria aimed to evaluate ten botanicals extracted in n-hexane, methanol and chloroform against African rice gall midge (AfRGM). The experiment was laid out in 10 x 3 factorial arrangements fitted into completely randomized design (CRD) with carbofuran and water as checks in three replications. The level of infestation by AfRGM significantly reduce in botanicals treated-plant particularly, on rice treated with Ageratum conyzoides and Chromolaena odorata extracted in n-hexane. A. conyzoides extracted in n-hexane (5.94 tons/ha) produced a significantly higher yield compared to other treatments, resulting into 73.91% yield increase over the control. There was a negative and significant correlation (r= - 0.60) between tiller infestation and grain yield, as well as other agronomic characters. Application of A. conyzoides extracted in hexane, exhibited better control of AfRGM and enhanced higher grain yield without adversely affecting agronomic traits.