Evaluation of 15 Varieties of Okra (Abelmoschus esculentus(L.) Moench to Field Infestation by Flea Beetles (Podagricaspp.)

Abstract

The study evaluated 15 okra varieties to field infestation by flea beetles, Podagrica spp., in the early and late planting seasons of 2009, at the Teaching and Research Farm, Federal University of Agriculture, Abeokuta, Nigeria (7°15′N 3°25′E), located in a sub-humid zone. The experiment was arranged in a split plot design, with three replicates. The main plot consisted of spraying regime (sprayed and unsprayed) while the sub-plot consisted of 15 okra varieties: V-35, V2-Oyo, V45-2, NH99/28, NH99/DA NH88/1-8-16-2, Enugu1, Osadep:purple Tall, LD88/1-8-5-2, LD88/1-8-16-2, Ola99/13, Ola3 Local, Olak2005, Short Mouth and Dajofolowo1. Lambda-cyhalothrin was sprayed to the appropriate plots weekly. The results showed that in both early and late seasons, sprayed okra had significantly (P < 0.05) lower number of flea beetles, lower leaf damage per plant, lower number of holes per leaf, wider stem girth, higher total plant dry biomass, higher number of pods compared with unsprayed okra. The sprayed okra had significantly (P < 0.05) higher shoot dry biomass, higher root dry weight, higher total plant dry biomass, wider pods and higher pod weight in the early planting season compared with the late season. Varieties with leaf pubescence, namely NH99/DA, V-35 and Dajofolowo1, had the lowest flea beetle population, leaf damage per plant and number of holes per leaf compared to glaborous varieties. Likewise, the okra varieties NH99/28, V-35 and Dajofolowo1 which have thorny pods had no pod damage at all in both early and late planting seasons. LD88/1-8-5-2 had the highest number of pods per plant, whereas okra variety Ola99/13 had significantly (P < 0.05) higher pod weight during early planting. There was no significant difference in okra pods weight in all varieties evaluated in the late planting season.