The effects of white clover mosaic virus infection on the yield of red clover (Trifolium pratenseL.) in mixtures and in pure stands

Abstract

SUMMARYThe effects of white clover mosaic virus infection on the yield of two red clover varieties grown alone and in mixtures with either perennial or hybrid ryegrasses were examined. The spread of this virus within the pure clover plots was rapid. Clover drymatter yields were reduced and these losses were greater in the grass–clover mixtures than in the pure clover plots. Reductions in yield of about 70% were recorded at the first cut in mixtures of Sabtoron and Sabrina. The response of the clover to different levels of virus infection was best described by a negative linear relationship.Yields of Sabrina hybrid ryegrass increased as the levels of virus infection in the clover increased. This compensated for the losses in yield of the legume, leaving total sward yields unaffected by the virus.