Comparative assessment of novel herbicide molecules and their effects on weed dynamics in sugarcane

A field experiment was conducted at the Vasantdada Sugar Institute, R&D Farm, Manjari, Pune, during the 2023-24 and 2024-25 cropping seasons to evaluate the efficacy of novel herbicide molecules for weed management in sugarcane. The study employed a Randomized Block Design (RBD) comprising nine treatments with three replications. Treatments included pre-emergence (PE) and post-emergence (PoE) applications of advanced herbicide combinations: Clomazone + Metribuzine, Clomazone + Sulfentrazone, 2,4-D sodium salt + Metribuzine + Pyrazosulfuron ethyl, Halosulfuron methyl + Metribuzine, and Topramezone + Atrazine. These were compared against standard checks (Atrazine and 2,4-D sodium salt), a weed-free control, and a weedy control. The results demonstrated that the PoE application of Halosulfuron methyl + Metribuzine (readymix) at 1 L ha⁻¹, applied at the 2-4 leaf stage of weeds followed by earthing up at 120 days after planting (DAP), achieved the highest cane yield (121.37 t ha⁻¹), the lowest weed index (10.40), and the best benefit-cost ratio (1:2.38). Conversely, the maximum commercial cane sugar (CCS) yield of 17.58 t ha⁻¹ and superior weed control efficiency (93.91%) were recorded with the PE application of Clomazone 30% + Sulfentrazone 28% WP (ready mix) at 2.5 kg ha⁻¹, followed by a single intercultivation at 60 DAP (partial earthing up). Overall, both Halosulfuron methyl + Metribuzine and Clomazone + Sulfentrazone herbicide combinations proved highly effective in suppressing weed infestation, enhancing cane productivity, and improving economic returns under the peninsular agro-climatic conditions of Maharashtra. These findings offer promising options for integrated weed management in sugarcane cultivation.