Oryza sativa plant traits conferring competitive ability against weeds

This study was conducted in lowland fields at the International Rice Resear ch Institute in the 1994 wet season and the 1995 dry season to determine Or yza sativa plant traits that confer competitive ability against weeds when pregerminated seeds are sown on puddled soil. Initial biomass (IB), crop gr owth rate (CGR), leaf area index (LAI), and biomass at tillering of O. sati va plants were associated with their competitiveness against weeds, whereas relative growth rate, net assimilation rare, and tillering capacity of O. sativa were not. Biomass at tillering affected weed biomass directly, and I B, CGR, and LAI indirectly affected weed biomass through O. sativa biomass. Biomass at tillering was the best predictor of modern cultivar competitive ness against weeds.