Effect of annual ryegrass (Lolium rigidum Gaud.) on yield of wheat

Abstract

Summary:The effect of five densities of annual ryegrass (Lolium rigidum Gaud.) on the growth, moisture usage and grain yield of wheat at three sowing times was determined in the field. The presence of ryegrass reduced wheat dry matter production and grain yields by decreasing fertile tiller and fertile spikelet production. Ryegrass was more competitive in the later sown crops and its effect on wheat grain yield was directly proportional to the square root of its density. The relationship between ryegrass density and wheat yield reduction is quantitatively described.