Influence of tillage and management inputs on weed growth and above ground biomass and yield of wheat varieties

Fields experiments were made in 1999 and 2000 to investigate the effects of conventional (CT) and zero tillage (ZT), three levels of herbicides rates and three nitrogen (N) levels on weed growth and wheat production. There was a higher grain yield for ZT system compared with CT in one of the two years evaluated. Weed biomass from CT was lower than from ZT in both varieties. No differences on wheat biomass and grain yield were observed between full and reduced rate of herbicide. N fertilizer increased significantly wheat biomass and grain yield. Only N medium level had effect upon weed biomass with respect to unfertilized plots, while the highest fertilization rate lowered weed biomass. Tillage system, herbicide reduced rates and nitrogen fertilization were an effective way of limiting weed production in wheat production systems.