Abstract

Tomato leaf miner, Tuta absoluta (Meyrick) is a devastating pest of tomato originating from South America which has been recorded in Ethiopia throughout tomato growing areas since 2012. The larvae damages the above ground parts of the plant especially leaf and fruits from seedling stage to maturity. Studies were conducted between 2015 and 2016 for two seasons to screen medicinal plants for the management of T. absoluta under laboratory and glasshouse conditions. Crude extracts of Phytolacca dodecandra seed and leaf, Allium sativum, Nicotiana species, Cymbopogon citrates and Azadirachta indica seed were evaluated at 5, 7.5, and 10% concentrations in the laboratory. Treatments which were found to be the best in the management of T. absoluta under laboratory condition were further evaluated for their efficacy under glass house condition. The mean percentage mortality of larva was recorded for 120 h after treatment application under laboratory study. The highest larval mortalities of 98.33, 96.67 and 95% were recorded for A. indica, C. citrates and A. sativum all at 10% concentration, respectively. In glasshouse experiment, A. indica gave the highest larval mortality of 66.54 % and the lowest percent mortality was recorded in P. dodecandra leaf and seed in both under laboratory and glasshouse conditions. With the obtained results, it can be concluded that foliar application of the mentioned medicinal plants extract on tomato plants reduced T. absoluta population and improved the quality and quantity of tomato fruit yield.

Key words: Medicinal plant, Tuta absoluta, Lycopersicon esculentum, crude extracts, efficacy, concentration.