Bio-Efficacy of New Herbicide Molecules for Weed Management in Grain Legumes

Abstract

Grain legumes including pigeon pea, chickpea, peanut, soybean, lentil, cowpea, common bean, faba bean, pea, and horse gram are extensively cultivated globally. Higher protein content, coupled with symbiotic nitrogen-fixing bacteria in root nodules enabling nitrogen fixation, highlights their importance in minimizing fertilizer use for agricultural production systems. Legume cultivation is limited by prolonged weed interference which is managed either through mechanical, cultural, chemical, or biological methods separately or in combinations. Nevertheless, herbicides remain and will persist as a crucial and economical element in global crop cultivation. While first-generation herbicides benefit agriculture, their long-term persistence and off-target toxicity have significant negative consequences, causing harm to both the environment and humans. Moreover, weed resistance and similar chemistry enforce the demand for new modes of action. Therefore, continuous research into new herbicides is important for combating herbicide resistance and ensuring crop output. In recent years, a few herbicides with novel mechanisms of action have occurred. Plants treated with new-generation herbicides resulted in increased WCE (weed control efficiency), decreased weed dry matter, and seed yield. There were no or minimal phytotoxicity symptoms observed on the existing and succeeding crops. This review emphasizes the importance of newly formulated herbicides signifying high selectivity, low toxicity, target specificity, and minimal application rates, contributing to an enhanced understanding of human and environmental health. Furthermore, it emphasizes the significance of economic viability and environmental friendliness in these formulations.