Effect of topramezone herbicide on weed suppression, crop safety and productivity in chickpea (Cicer arietinum L.)

Chickpea (Cicer arietinum L.) productivity is often constrained by severe weed infestation, particularly during early growth stages, necessitating efficient and safe weed management strategies. The use of post-emergence herbicides is limited due to potential crop phytotoxicity, highlighting the need for alternative options. A field trial was undertaken at Sriniketan, West Bengal, during the rabi seasons of 2021–2022 and 2022–2023 to study the performance of topramezone at different application rates as a post-emergence herbicide in chickpea cultivation. The experiment followed a randomised block design consisting of 9 treatments replicated 3 times, comparing topramezone (15–25 g ha-1) with standard herbicides, pendimethalin and imazethapyr. Results revealed that application of topramezone at 25 g ha-1 at 25 days after sowing significantly reduced weed density and dry weight, resulting in improved crop growth and productivity. This treatment showed performance comparable to pendimethalin (750 g ha-1) and superior to imazethapyr (60 g ha-1). European Weed Research Council (EWRC) phytotoxicity scores for all topramezone treatments remained at one across all observation intervals, indicating no crop injury, whereas imazethapyr caused transient phytotoxicity (score up to 4 at 7 days after herbicide application) that declined by 30 days after application. Higher plant height, leaf area index, dry matter accumulation and seed yield (1402.58 kg ha-1) were recorded under this treatment. The study demonstrates that topramezone at 25 g ha-1 can serve as an effective and safe post-emergence herbicide in chickpea cultivation.