Competitive Relationships and Critical Weed-Free Period of Rumex dentatus in Lentil Under Rainfed Conditions

Abstract

Weed interference is a major limiting factor in lentil production under rainfed conditions, where Rumex dentatus has emerged as a competitive and persistent broadleaf weed. The present study investigated the competitive relationships between R. dentatus and lentil, along with the determination of the critical weed-free period required to minimize yield losses. Field experiments were conducted under rainfed conditions using varying weed emergence timings and densities to assess crop–weed interaction effects on growth and yield parameters. Results indicated that R. dentatus significantly reduced lentil plant height, branch number, biomass accumulation, and pod formation due to strong competition for soil moisture, nutrients, and light resources. Early-season interference caused the greatest yield reduction, highlighting the importance of weed control during initial crop establishment. Competitive analysis revealed that R. dentatus exhibits aggressive growth behavior under moisture-limited conditions, enabling rapid canopy development and suppression of lentil growth. The critical weed-free period was identified as the early vegetative stage of lentil growth, during which weed presence must be minimized to prevent irreversible yield losses. Delayed weed control beyond this period resulted in substantial reduction in grain yield and economic returns. Rainfed conditions intensified crop–weed competition due to limited water availability, further enhancing the competitive advantage of R. dentatus. The study emphasizes that timely weed management is essential for maintaining lentil productivity in dryland farming systems. Overall, R. dentatus demonstrates strong competitive ability in lentil fields, and effective management during the critical weed-free period is crucial for sustainable production. Integrated weed management strategies combining cultural, mechanical, and chemical approaches are recommended for efficient suppression of this weed in rainfed agroecosystems.