Competitive Effects of Echinochloa crus-galli Density on Growth Parameters and Grain Yield of Transplanted Rice

Abstract

Weed competition is a major constraint in transplanted rice cultivation, significantly reducing crop growth and grain productivity under intensive production systems. The present study evaluated the competitive effects of varying densities of Echinochloa crus-galli on growth parameters and grain yield of transplanted rice under field conditions. Different weed density treatments were established to assess their influence on rice growth, physiological performance, and yield components throughout the cropping season. Observations were recorded on plant height, number of tillers, leaf area, dry matter accumulation, panicle characteristics, and final grain yield. The results demonstrated that increasing densities of E. crus-galli caused significant reductions in rice growth and yield attributes due to intense competition for light, nutrients, moisture, and space. Higher weed densities markedly suppressed tiller production and biomass accumulation, leading to reduced panicle formation and lower grain yield. Severe infestations resulted in substantial yield losses compared to weed-free conditions. The competitive ability of E. crus-galli was particularly pronounced during the early growth stages of rice, where rapid weed establishment limited crop development and resource utilization. Correlation analysis indicated a strong negative relationship between weed density and grain yield parameters. The findings highlight the importance of timely and effective weed management practices for minimizing competition and improving rice productivity. The study provides valuable insights into the competitive dynamics of E. crus-galli in transplanted rice ecosystems and supports the development of integrated weed management strategies aimed at sustainable crop production and reduced yield losses.