Herbicidal Efficacy of Imazethapyr for Weed Management in Chickpea (Cicer arietinum L.) under Lateritic Soils of West Bengal

Abstract

A field experiment was conducted during the rabi season of 2020–21 at the Agricultural Farm of the Institute of Agriculture, Visva-Bharati, Sriniketan, West Bengal, to evaluate the herbicidal efficacy of imazethapyr applied as pre- and post-emergence for weed management in chickpea (Cicer arietinum L.) under lateritic soil conditions. The experiment was laid out in a randomized block design with nine treatments replicated three times, comprising imazethapyr at 30, 40, and 50 g ha⁻¹ applied as pre-emergence (PE) and post-emergence (POE), pendimethalin at 750 g ha⁻¹ as PE, a weed-free treatment, and a weedy check. Results indicated that weed density, weed dry weight, and weed control efficiency were significantly influenced by the dose and time of herbicide application. Post-emergence application of imazethapyr proved more effective than pre-emergence application in suppressing both grasses and broad-leaved weeds. Among imazethapyr treatments, application at 50 g ha⁻¹ as post-emergence recorded lower weed density and dry weight, higher weed control efficiency, and improved growth parameters, including plant height, leaf area index, and crop growth rate. These improvements resulted in higher biological yield and seed yield compared to lower doses and pre-emergence applications of imazethapyr. However, pendimethalin at 750 g ha⁻¹ as pre-emergence and the weed-free treatment achieved the highest weed suppression, crop productivity, and economic returns, while the weedy check recorded the lowest yields due to severe weed competition. The study concludes that pendimethalin as pre-emergence remains the most effective chemical weed management option in chickpea, while imazethapyr at 50 g ha⁻¹ applied as post-emergence serves as an efficient and practical alternative when pre-emergence application is not feasible.