MIXTURES OF WILD OATS (AVENA-FATUA) AND RYEGRASS (LOLIUM-RIGIDUM) IN WHEAT - COMPETITION AND OPTIMAL ECONOMIC-CONTROL

The joint control of wild oats (A vena fatua) and ryegrass (Lolium rigidum) in mixture in a wheat crop using a single postemergence herbicide, diclofop-methyl, was examined. The two weeds were found to have different competitive strengths against wheat and different degrees of sensitivity to the herbicide. Response surfaces to different rates of herbicide and different weed densities were estimated statistically and these functions were used to examine optimal control practices for different mixtures of the weeds.