EFFECT OF N-FERTILIZER AND FARMYARD MANURE ON WEED COMPETITION IN RICE

A field study was conducted to evaluate the effect of nitrogen (n) rate (recommended and half dose) and farmyard manure (fym) on weed competition in rice (oryza saliva) var. super basmati. four frequently occurring weeds viz., echinochloa colonum, cyperus rotundus, marsilea minuta and paspalum paspaloides were grown in rice in a 1:1 ratio of weed and rice plants. the highest vegetative growth and grain yield in weed free control plots was observed in fym followed by full n and half n dose of fertilizers, respectively. maximum losses in plant biomass and grain yield due to weed competition were recorded in fym. percentage losses in half and full dose of n due to different weeds were close to one another. mixed weeds in all the three types of amendments generally were more damaging as compared to either of the four weed species. weed biomass was generally greater in fym and full n dose as compared to half n dose.