Evaluation of Some Botanical Extracts and Chemical Insecticides against Cabbage Aphids, Brevicoryne brassicae L. (Hemiptera: Aphididae) on Cabbage (Brassicae oleracea) in West Shoa of Oromia, Ethiopia

Abstract

Cabbage is Ethiopia's second most significant vegetable crop after red pepper (Capsicum spp), although its yield and yield components are influenced by a variety of factors, including cabbage aphids, which are a major pests in most of Ethiopia's cabbage-growing areas. This study was conducted to evaluate a newly introduced chemical insecticide (Kanthion 50% E.C), and locally available botanicals. Each treatment was replicated three times and the entire setup was arranged in a randomized complete block design (RCBD) under field conditions. In the field, among the botanicals tested, N. tabacum, A. sativum, and lemon extract resulted in the highest percentage of nymphs and adult mortality greater than 65% within three days after application. In the field, non-treated control plants showed low yield as compared to the chemical, and botanical insecticide. The highest fresh weight (3.01 kg) was obtained from plants treated with Kanthion 50% E.C. This study indicates that Kanthion 50% E.C, N. tabacum, A. sativum, and Citrus limon could be recommended as an alternative management option against Brevicoryne brassicae (L) under field conditions.