Effect of crude ethanolic leaf extract of soursop Annona muricata L.) on eggplant shoot and fruit borer (leucinodes orbonalis guen.)

Thumbnail Image
Journal Title
Journal ISSN
Volume Title
Eggplant is an important source of income to rural farmers who grow the crop either once or twice a year to augment income from other farming activities. The main production constraint apart from unpredictable weather is damage to shoots, flowers and fruits of the plant by the eggplant shoot and fruit borer, Leucinodes orbonalis (Guen.). The use of synthetic insecticides for the control of this borer has been the standard practice. However, an increasing awareness of the environmental hazards associated with insecticide use as well as the high costs of control is intensifying the demand for a less hazardous form of control. Biopesticides have long been an alternative to synthetic chemical insecticides for pest management because botanicals apparently pose little threat to the environment and to human health. Literature documenting bioactivity of plant derivatives to insect pests continue to increase, yet only a handful of botanicals are currently used in agriculture. Products based on pyrethrum, rotenone and azadirachtin have been used at different levels of sophistication. This study investigated the bioactivity of Annona muricata ethanolic leaf extract against L. orbonalis on eggplant in the field. Three levels of the leaf extract - 0.25%, 0.50% and 1.0% - were tested along with a synthetic insecticide Dimethoate and water control to assess the potency of the extract in controlling the damage inflicted on the shoots, flowers and fruits of eggplant by L. orbonalis. Results from the investigation showed that the leaf extract was fairly effective against L. orbonalis. Even though the extract could not completely prevent damage to shoots, flowers and the fruits of the eggplant, it significantly reduced the damage even though not as effective as Dimethoate.
A Thesis submitted to the School of Graduate Studies, Kwame Nkrumah University of Science and Technology, Kumasi, in partial fulfilment of the requirements for the Degree of Master of Science in Crop Protection (Entomology),