Dynamic Weed Control through Targeted Herbicide in Transplanted Black Rice (Oryza sativa L.) under Eastern Uttar Pradesh, India

Abstract

Weed management remains a major challenge, especially under intensive cropping systems in rice cultivation. There is a need to adopt advanced weed control strategies that enable selective suppression of weed flora while minimizing crop injury. However, the indiscriminate and continuous use of single herbicide molecules has led to the emergence of herbicide-resistant weed biotypes, necessitating integrated and rotational approaches. The present field investigation was conducted during the Kharif season (June–November 2024) at the Agricultural Research Farm, Institute of Agriculture and Natural Sciences, Deen Dayal Upadhyaya Gorakhpur University, Uttar Pradesh, India, to evaluate the efficacy of various herbicide combinations on weed dynamics in transplanted black rice (Oryza sativa L.). The experiment consisted of seven treatments: T1 (100% RDF + Weedy Check), T2 (100% RDF + Butachlor @750 g a.i./ha + Triafamone @40 g a.i./ha), T3 (100% RDF + Butachlor @750 g a.i./ha + Bispyribac Sodium @150 g a.i./ha), T4 (100% RDF + Butachlor @1500 g a.i./ha), T5 (100% RDF + Triafamone @40 g a.i./ha), T6 (100% RDF + Bispyribac Sodium @300 g a.i./ha), and T7 (100% RDF + Hand Weeding). Results indicated that T7 (Hand Weeding) was the most effective in reducing total weed density and provided complete suppression of dominant weed species while cost intensive. Among the herbicide-based treatments, T3 showed superior performance, significantly reducing weed density and achieving the highest weed control efficiency due to its broad-spectrum activity. These findings suggest that the strategic use of herbicide combinations can effectively manage weed populations and prevent resistance buildup, thereby supporting sustainable black rice production in Eastern Uttar Pradesh.