Field Evaluation of Botanicals against the Insect Pests of Okra (Abelmoschus esculentus Moench.)

  • F. P. Neupane Institute of Agriculture and Animal Science, Tribhuvan University, Rampur, Chitwan

Abstract

The derivatives of the following pesticidal plants were tested in the field as crude water extract sprays onokra (Abelmoschus esculentus Moench.) plants. (1) neem (Azadirachta indica A. Juss) green leaves @ 200g/l, and seed kernel powder @ 30g/l; (2) chinaberry (Melia azedrach L.) green leaves @ 200g/l; (3) ageratum (Ageratum conyzoides L.) fresh flowers @ 200 g/l; (4) Justicia (Justicia gendarussa Brum. f.) green leaves @200 g/l; and lantana (Lantana camara L.) green leaves @ 200 g/l. Monocrotophos (0.05%), an insecticide, was also sprayed as a standard check. The main objectives of this test were (i) to compare the efficacies of the above materials against the cotton leafhopper (Amrasca biguttula biguttula Ishida), the okra shoot and fruit borer (Earias vittela Fab.) and the red cotton bug (Dysdercus koneigii Fab.); and (2) to assess the effect of the above materials on growth and yield of okra plants. Monocrotophos was significantly (P<0.05) superior to all the botanical derivatives mentioned above in the overall suppression of the above insect pests, and better growth and yield performance of okra plants. Most of the botanicals, particularly neem (seed kernel) and Justicia (leaves) were able to reduce the leafhopper population to some extent, and protect okra foliage from its severe feeding damage. Neem seed kernel also recorded the lowest infestation of the okra shoot and fruit borer. Both neem seed kernel and chinaberry leaves were better than the rest of the botanicals in reducing the red cotton bug population. Neem seed kernel and Justicia leaves showed better performance on okra fruits (weight and number of fruits per plant) and plant growth (height and weight).