Assessment of Post-Emergence Herbicides in Sugarcane (Saccharum officinarum L.)

Abstract

Sugarcane (Saccharum officinarum L.) is one of the most important commercial cash crops in India, contributing substantially to the production of sugar, jaggery, and ethanol and to rural livelihoods. Weed infestation during the early crop growth period remains a major biotic constraint, limiting cane productivity and profitability across tropical regions. Manual weeding has become increasingly difficult because of severe agricultural labour shortages and rising wage rates, necessitating effective, low-dose post-emergence herbicide combinations. A two-year on-farm trial (OFT) was conducted during the Rabi seasons of 2023–24 and 2024–25 in the Vizianagaram district of Andhra Pradesh to evaluate the field-level efficacy of modern post-emergence herbicides in sugarcane. Three treatments were evaluated: farmer’s conventional weed management practice (T1), Tembotrione @ 287.5 ml/ha applied at 25–30 days after planting (T2), and a tank-mix combination of Tembotrione @ 287.5 ml/ha + Halosulfuron methyl @ 100 g/ha applied at 25–30 days after planting (T3). Total weed density, cane yield, and economics (gross returns, net returns, and benefit-cost ratio) were compiled and assessed. The pooled analysis of the two-year trial indicated that the combined application (T3) recorded the lowest weed density (10.76 weeds/m2), the highest cane yield (86.59 t/ha), the highest gross income (₹2,07,468/ha), the highest net income (₹71,123/ha), and a superior benefit-cost ratio (1.52). Conversely, the farmer’s practice (T1) resulted in the highest weed infestation (49.18 weeds/m2) and the lowest cane yield (63.36 t/ha). The combined post-emergence herbicide treatment enhanced cane yield by approximately 36.7% over the farmer’s conventional practice while substantially maximising farm profitability. These findings indicate that the combination of Tembotrione and Halosulfuron methyl provides a broad-spectrum, highly effective post-emergence weed management option that enhances sugarcane productivity in North Coastal Andhra Pradesh while reducing heavy dependence on manual labour.