Efficacy of insecticides and application frequencies for the management of chickpea pod borer (Helicoverpa armigera) in Bale zone, Oromia region, Southeastern Ethiopia

Chickpea (Cicer arietinum L.) is an important grain legume worldwide, including Ethiopia as a secondary center of genetic diversity; however, production is severely limited by pod borer (Helicoverpa armigera) that can result in up to 100% yield loss. This study examined the effectiveness of three insecticides (Datrate 5% EC, High Pyro 220 EW, and Helarate 5% EC) applied at one, two, or three times against H. armigera on chickpea production at two sites in Bale, South Eastern Ethiopia (Sinana and Goro) during the 2021/22–2023/24 growing seasons using a field experiment based on a randomized complete block design with the Harbu variety. The results indicated that the application of Datrate 5% EC three times resulted in the lowest larval reduction (94.06% at Sinana, 90.75% at Goro) and pod damage (16.55% at Sinana, 23.18% at Goro), with the highest grain yield (36.66 qt/ha at Sinana, 31.93 qt/ha at Goro) compared to control (15.12 qt/ha at Sinana, 12.87 qt/ha at Goro). Economic analysis showed that three applications of Datrate 5% EC had the highest net benefit (216,901.05 ETB ha⁻¹), with a marginal rate of return of 8,946.81%. A very strong negative correlation (r = -0.99) was observed between pod damage percentage and grain yield, which means that the higher the percent of damaged pods, the lower the yield, and each 1% increase in damaged pods reduces yield by 0.8327 qt/ha. While three applications of Datrate 5% EC were most effective, environmental risks and pesticide resistance require that chemical control be combined with biological and cultural methods within an integrated pest management framework. These results can serve as a basis to enhance H. armigera management for sustainable chickpea production in Ethiopia.