<i>Ascochyta fabae</i> on winter beans ( <i>Vicia faba):</i> pathogen spread and variation in host resistance

Abstract

SUMMARY In two crops of winter beans ( Vicia faba L.) grown in Cambridgeshire, one in 1975 and the other in 1976, a decreasing frequency of Ascochyta ‐infected winter bean plants from the border to the centre suggested that spread from volunteer plants in adjacent fields was a much more important source of infection than infected seed. From February to May in both years the disease spread into the field for a distance of at least 120 m. Within a trial situated in a heavily infected area in 1975, differences in degrees of infection between genotypes were recorded. On 21 May 1975 the trial entries IB19, Bulldog, Banner, Buccaneer, IB7CS, IB18 and Maris Beagle had significantly fewer lesions than Throws MS, HYBSYN, WHT, IB15, IB17 or IB14.