Flea beetle populations and economic yield of Okra as influenced by Nitrogen and 2, 3-Dihydro-2, 2-Dimethyl Benzofuran

Abstract

Nitrogen fertilisation and carbofuran applications impact plants, yet few studies examine their general impact on plant performance and plant susceptibility to insect pests and diseases when applied together. The performance of okra (Abelmoschus esculentus L. Moench) and infestations by flea beetles in relation to nitrogen and carbofuran applications were, therefore, evaluated under a humid tropical environment. Treatments comprised of combinations of four rates of 2, 3-dihydro-2, 2-dimethylbenzofuran or carbofuran (0.0, 0.5, 1.0 and 1.5 kg ha -1) and four levels of N-fertiliser (0, 40, 80 and 120 kg ha -1 ). The presence of Podagrica uniformis was recorded much earlier on the plants than Nisotra sjostedti. The population of either flea beetle remained lower throughout the vegetative than the reproductive phase. While N fertilisation resulted in higher insect count than where no N was added, carbofuran at 1.0 kg ha -1 and above significantly (P<0.05) depressed the flea beetle populations up to 5 weeks after planting. Differences in the carbofuran and N interaction had no statistical significance on insect count. All cases of applied carbofuran and nitrogen increased earliness to maturity, plant height, total fruit number, fruit weight, fruit yield and net marginal returns. Higher doses of carbofuran in combination with nitrogen significantly increased earliness to plant maturity, fruit number per plant, fruit yield and net marginal returns. The best fruit yield was attained by combining 1.0 kg ha La population de coléoptères était restée plus basse dans la phase végétative que dans la phase reproductive. Alors que le nombre d'insects était plus élevé dans les traitement sous fertilization azotée que dans le contrôle, la dose de plus ou moins 1.0 kg ha -1 de carbofuran avait significativement (P<0.05) réduit les populations de coléoptères jusqu'à cinq semaines après le semis. Aussi, il n'yavait pas eu de difference significative en terme d'interaction entre le carbofuran et d'azote appliqués. Dans tous les cas, le carbofuran et l'azote avait eu un effet sur la maturation précoce, la hauteur de plants, le nombre total de fruits, le poids de fruits, le rendement en fruits ainsi que sur des bénéfices marginaux nets. La combinaison de doses élevées de carbofurant et d'azote avait affecté significativement la susceptibilité de la plant à la maturation précoce, le nombre de fruits par plant, le rendement en fruits et les bénéfices marginaux nets. Le meilleur rendement en fruit était realisé par la combinaison de 1.0 kg ha , alors que la combinaison de 0.5 kg ha -1 de carbofuran avec 80 kg ha -1 d'azote était la meilleure du point de vue de la rentabilité économique. L'incidence de la maladie de mosaïque était controlée soit par l'augmentation des doses de carbofuran ou par la diminution des doses d'Azote.

Susceptibility of different Malvaceae crops to herbivory induced by adult Podagrica spp.

“…Apart from the cotton, all crops evaluated could be categorized as susceptible to P. uniforma and P. sjostedti attacks due to the high infestation and damage levels observed. This further confirms previous reports on the economic damage caused by the attacks of the beetles on crops in the Malvaceae family (Echezona et al, 2010;Pitan & Adewole, 2011;Pitan & Ekoja, 2011;. Interestingly, all the cotton genotypes used in the study seem not to be attractive to the beetles, as there were no visible symptoms of damage on all parts of the crops.…”

Integrated management of flea beetle and thrips on mungbean in coastal habitat

“…Flea beetles cause significant loss at various stages of the crops up to harvest, damaging leaves that wither and hamper plant growth with minimal pods. This result is supported by (Echezona et al, 2010). The incidence and development of the flea beetle is highly dependent on the prevailing weather conditions, which consistent with Khan et al (2018).…”

Effect of Nitrogenous Fertilizer and Insecticides on Incidence of Leafhopper, Amrasca biguttula biguttula (Ishida) in Kharif Okra

“…Scanty information is available so far effect of nitrogenous fertilizer on the effectiveness of insecticides against leafhopper is concerned in okra crop. Echezona et al, (2010) reported that the higher okra fruit yield was recorded by combining of 1.0 kg/ha carbofuran with 80 kg N/ha, while, the best economic return was achieved by combining of 0.5 kg/ha carbofuran with 80 kg N/ha. Under the present investigation, more or less similar trend was found.…”