Bioefficacy of Tagetes minuta L. against Aphis craccivora Koch (Hemiptera, Aphididae)

Abstract

Efficacy of solvent fractions of Tagetes minuta L. (hexane, chloroform and aqueous fractions of aerial parts) was evaluated against Aphis craccivora Koch at five different concentrations (0.025, 0.05, 0.1, 0.15 and 0.2%) in the laboratory. At higher concentrations, all the fractions recorded significant reduction in aphid count; maximum reduction after 120h of treatment was in hexane fraction at 0.2 per cent (90.00%), followed by chloroform fraction at 0.2 per cent (86.67%) and aqueous fraction at 0.2 per cent (85.00%). The best concentrations of the three solvent fractions of T. minuta identified in the laboratory were evaluated against the aphid on cowpea, in a pot culture experiment. By 10th day of treatment, all the fractions at 2 per cent concentration reduced population of aphids, with the highest reduction in hexane fraction.