Assessment of Weed Indices and Correlation Analysis under Different Herbicidal Weed-Management Practices in Green Gram (Vigna radiata L.)

Abstract

Background: Weed infestation is a major constraint in green gram (Vigna radiata L.) production and causes substantial yield losses through severe crop-weed competition during the early growth stages. Objective:  The present investigation was conducted to assess weed indices and to elucidate the relationship between weed density, weed biomass and seed yield under various herbicide-based weed management practices in green gram. Methodology: A field experiment was conducted during the summer seasons of 2024 and 2025 at the Instructional Farm, College of Agriculture, Dapoli, Maharashtra, India. The experiment was laid out in a randomised block design with twelve treatments and three replications, comprising pre-emergence, post-emergence, sequential herbicide applications, weed-free and unweeded check treatments. Weed indices and correlation coefficients between weed parameters and seed yield were computed. Results: Among the herbicidal weed-management treatments, pre-emergence application of pendimethalin 38.7% CS at 677.25 g a.i. ha-1 followed by post-emergence application of fluazifop-p-butyl 11.1% + fomesafen 11.1% SL at 250 g a.i. ha-1 recorded higher weed-control efficiency and a lower weed index, followed by pre-emergence application of oxyfluorfen 23.5% EC at 120 g a.i. ha-1 followed by fluazifop-p-butyl 11.1% + fomesafen 11.1% SL at 250 g a.i. ha-1. Correlation analysis revealed significant negative associations between seed yield and weed density and biomass. Digitaria sanguinalis L., Physalis minima L., Cardiospermum halicacabum L. and Celosia argentea L. exhibited strong negative correlations with seed yield, indicating substantial competitive effects on crop productivity. Conclusion: The study demonstrated that effective weed management through sequential herbicide application improved weed control and minimised yield losses in green gram. The strong negative association between weed infestation and seed yield highlights the importance of timely weed suppression for enhancing crop productivity under Konkan agro-climatic conditions.