Field Evaluation Of The Insecticidal Properties Of Ocimum Gratissimum On Amaranthus Pest

ABSTRACT

The insecticidal properties of Ocimum gratissimum on Amaranthus spp was investigated in umudike between June to August 2008. 0. gratissimum was intercropped with Amaranthus in 10 replicates, a control with Amaranthus only was also in place. The insects pests encountered were of orders Heteroptera, Lepidoptera, Coleoptera and Orthoptera. The insects included Nezara uiridula, Asp avia armigera (Heteroptera), Sylepta derogata, Spodoptera littoralis (Lepidoptera), Zonocerus variegatus (Orthoptera) and Epilachna spp (Coleoptera). N. viridula was most abundant. The P. gratissimum controlled the population of N. Viridula. The population of N. viridula recorded on Amaranthus intercropped with 0. gratissimum were 1.25 (± 1.14), 1.67 (± 1.29) and 1.67 (± 1.29) while for Amaranthus only, the values recorded were 2.98 (± 1.65), 4.76 (± 2.18) and 7.74 (± 2.79). The influence of 0. _gratissimum on population of N. viridula and the larvae of the Lepidopterans recorded significance (at P < 0.05) as Amaranthus grew on to maturity. Its influence did not affect seed production as percentage seeds produced from both replicates recorded 29.6 and 29.3 respectively. This implies that 0. gratissimum has potentials for the control of the serious pest of Amaranthus spp in our locality.