Abstract

The Onion crop is attacked by many insect pests, among these onion thrips is a major pest. The purpose of this study was to find the efficacy of different insecticides against thrip to improve the quality and quantity of onion production. Therefore, a field experiment was conducted to evaluate the insecticidal application and with frequency of application in 2017 and 2018 under irrigation conditions. The experiment was conducted using a Randomized Complete Block Design (RCBD) with thirteen treatments involving three different insecticides: Karate 5 EC, Dimethoate 40 EC, and Profit 72 EC, along with four different spraying frequencies and an untreated control group, all replicated three times. The results showed that the highest profitable yield in Tselemti woreda was achieved with Karate 5 EC in the first spray (14.25 t ha-1), followed by Profit 72 EC in the fourth spray (20.25 t ha-1), yielding profits of 128053 and 181788 birr ha-1, with marginal rates of return of 3025 and 2417%.In Medebaayzana woreda, the top yield was also with Karate 5 EC (first spray at 25.79 t ha-1), followed by Karate 5 EC (fourth spray at 27.75 t ha-1) and Dimethoate 40 EC (third spray at 25.78 t ha-1), resulting in profits of 231976, 249463, and 231544 birr ha-1, with return rates of 2634, 2395, and 2311%. In summary, Karate 5 EC (first spray) and Profit 72 EC (fourth spray) in Tselemti, along with Dimethoate 40 EC (third spray) in Medebaayzana, were effective in preventing onion thrips and improving onion production.

Key words: Bioefficacy, Crop, Different doses, Enormous potential, Insecticides, Onion, Onion Thrip