STUDY EFFECT OF TILLAGE, HERBICIDE AND FERTILIZER RATES ON WHEAT (TRITICUM AESTIVUM) AND WEED POPULATIONS IN IRAN

Wheat grain production will not be sufficient for the increasing world population demands in next decades. The aim of integrated weed management (IWM) is to use of a combination of different practices to maintain weed densities at manageable levels. Field experiments were carried out in 2005 and 2006 to investigate the effects of conventional (CT) and no-tillage (NT) systems, interacting with three herbicide dose levels and three nitrogen (N) levels on weed growth and wheat production of two varieties Zarrin and Pishtaz in Agronomy College, University of Tehran. There was a higher grain yield for NT system compared with CT in one year. CT weed biomass was lower than from NT weed biomass, in both varieties. No differences on wheat biomass and grain yield were observed between full and reduced herbicide rates. N fertilizer increased wheat biomass and grain yield significantly. Only N medium level had an effect upon weed biomass with respect to non-fertilized plots, while the highest fertilization rate lowered weed biomass. Conventional tillage, reduced herbicide rates and nitrogen fertilization were effective ways of limiting weed production in wheat.

Integrated weed management, tillage, herbicide, fertilizer, wheat