Ascochyta Leaf and Pod Spot

Ascochyta leaf and pod spot is caused by Ascochyta fabae, which is carried in the seed coat of the seed. Initial symptoms are seen on the young leaves of seedlings growing from infected seed, spots are up to 1cm long, with a chestnut brown edge. In severe attacks plants can be defoliated and pods become covered in lesions. Seeds from infected pods may be stained by the pathogen, although not all infected seed is marked in this way.
In our laboratory a trained mycologist identifies the Ascochyta using a range of distinguishing features. The result is reported as the percentage of the seed infected. NIAB recommends that seed with an infection of more than 1% should be treated and those above 6% should not be used at all.