Morphophysiological and biochemical parameters associated with competitive ability of rice genotypes against weeds

Rice production suffers a major setback through weed pressure world wide. The present investigation was carried out to analyse the rice plant characteristics associated with the competitiveness against weeds. The experiment was conducted for two years (2009 and 2010) in a split-plot design with the weedy and weed-free treatments in the main plot and ten rice genotypes as the sub-plot treatment. Results indicated that rice genotypes showed variable competitiveness against weeds. Among the genotypes, highest crop weed competitive index (CWCI) was found in Govind and UPR 2962-6-2-1. The competitive ability of these genotypes could be attributed to biomass production during early vegetative stage, growth parameters like leaf area index, tiller number, and plant height and biochemical parameters such as shoot N and chlorophyll content.