Evaluation of aqueous extracts of five plants in the control of flea beetles on okra (Abelmoschus esculentus (L.) Moench)
Agricultural Science Department, Adeyemi College of Educatio, P.M.B. 520, Ondo, Nigeria
The emergence of biodegradable pesticides as safe option has reduced the problems that result from the use of synthetic insecticides, thus creating a renewed interest in their development and use in integrated pest management of crops. The objective of this study was to investigate the insecticidal properties of the water extracts of Jatropha curcas, Vernonia amygdalina, Ageratum conyzoides, Chromolaena odorata (L) and Annona squamosa on two species of flea beetles (Podagrica uniforma and P. sjostedti (Coleoptera: Chrysomelidae) infesting okra (Abelmoschus esculentus (L.) Moench), variety NHAE 47-4). The leaves and seeds of the plants used in the experiment were collected from the locality, washed and shade dried. A synthetic insecticide, lambda-cyhalothrin (karate) was included in the treatments as a standard check alongside the untreated (control). The experiment was laid out in a randomized complete block design (RCBD) with seven treatments and four replicates. The efficacy of the treatments was based on reduction in flea beetles and percentage reduction in population of the pests. The results showed that only three of the plant extracts (Jatropha curcas, Vernonia amygdalina and Annona squamosa) significantly (P < 0.05) reduced the population of the two flea beetles at 64%, 55% and 49%, respectively. Though the other two botanicals were not significant in reducing the population of the pests, they were better than the control. All the plant extracts tested were not as effective as the synthetic insecticide in reducing flea beetles population. Among the tested plants, J. curcas, was found to be more effective, hence its use by resource poor farmers is recommended in the protection of okra against the infestation of P. uniforma and P. sjostedti.© JBiopest.
Abelmoschus; Abelmoschus esculentus; Ageratum conyzoides; Alticini; Annona squamosa; Chromolaena; Chromolaena odorata; Chrysomelidae; Coleoptera; Gymnanthemum amygdalinum; Jatropha curcas; Podagrica; Siphonaptera (fleas); Vernonia amygdalina