Epsilon Open Archive

Abstract

We studied effects of crop rotations with different amounts of grass/clover ley, especially the effect of fodder rape on the development of clover root rot in red clover. Clover plants, one to three and a half years old, with the root-system were collected from a long-term crop rotation experiment in spring and late autumn. Disease severity index (DSI) of clover root rot and the abundance of the clover root rot causal organism Fusarium avenaceum was evaluated. The results showed that development of clover root rot clearly depends on the age of clover plants regardless of the cropping system. Even though there was a higher abundance of F. avenaceum in one year old clover from crop rotations with more ley, this effect did not persist with increasing age of clover. We did not find any robust correlation between the level of DSI and the abundance of F. avenaceum in clover root. In conclusion, the crops and crop rotations used in this long term-experiment were not effective as control of clover root rot and did not increase the longevity of clover in the leys. This project has been financed by The Royal Swedish Academy of Agriculture and Forestry.