Biorational Management of Flea Beetles. Podagrica spp. (Coleoptera: Chrysomelidae) and yield response of Okra (Abelmoschus esculentus) (L.) Moench.) In the Southern Guinea Savanna

Abstract:

This experiments conducted in 2019, to evaluate yield response of Okra (Abelmoschus esculentus, (L.) Moench) to attractiveness of colour sticky traps in relation to other population sampling methods and bio-pesticidal effects of Aqueous delonix seed extract on the flea beetles, Podagrica Spp. (Coleoptera: Chrysomelidae) in the Southern Guinea Savanna zone of Nigeria. Experimental design uses six coloured sticky traps as treatments in Randomized Complete Block Design (RCBD) and replicated three times. The design for efficacies of Bio-pesticides also in RCBD had four replications and five application rates, including a positive check and zero control as treatments. Yellow colour traps gave higher mean Podagrica Spp., catches but damage was higher in the white and purple traps, indicating other contributive factors affecting beetles feeding on Okra fruits. Higher precision was observed in hitting methods, when combined with colour reflectance. Yield of Okra fruits was optimum in all treatments, being higher in purple and least in white traps plants. Heavier fruits and least yield losses were in the least infected navy-blue treated plots. Agronomic performance was better in bio-pesticide treated Okra plants, but were not significant across different application rates with 57.30cm2 peak leave area at 20g/l, while mean fruit yield of 1007.00 was recorded at 15g/l Aqueous delonix seed application rate. Control had lowest mean fruit yield (780.00) with the highest fruits damage (11.33) per plot but heavier fruits recorded in the treated plants at 30g/l (66.75kg) over Cypermethrin (61.05kg). Pest population census showed significant (P < 0.05) decrease with increased application rates of the bio-pesticides. Hitting as sampling method was superior over sweep netting and was significantly different (P < 0.05) across the bio-pesticides application rates.