Persistence Evaluation of Some Insecticidal Plants and Application Rate to Maize Weevil Damage in Stored Maize Grain

Abstract

A study was conducted to evaluate the persistence of insecticidal effects of some of botanicals and application on adult parent mortality of maize weevil in infested maize grain. Seven botanicals (Azadirachta indica (neem), Melia azedarach (melia), Parthenium hysterophorus (parthenium), Calpurnia aurea (calpurnia), Vernonia amygdalina (bitter leaf), Carica papaya (papaya) and Dichrocephala integrifolia) were tested each at three different rates viz, 2.5, 5 and 10% w/w. Malathion 5% dust at 0.05% as standard check and untreated check were included for comparison. Twenty unsexed adult weevils were re introduced to treated maize grains at 90 DAT and parent mortality was recorded at 93, 100, 107, 114, and 121 DAT. The experiment was laid out in a completely randomized design (CRD) in factorial arrangement and replicated four times. The result showed that A. indica, M. azedarach and D. integrifolia at all rates caused equal cumulative mortality (100%) with the synthetic insecticide, but the time required to totally kill the insects varied. All treatments caused significantly higher mortality than the untreated check after four months of storage.

DOI: 10.7176/JBAH/11-2-04

Publication date: January 31^st 2021