The stem is often completely girdled by these lesions or weakened so that it breaks. Both the main stem and lateral branches can be affected and close inspection will often show similar symptoms on petioles . Leaf lesions are not numerous but may be seen as beige spots with a dark brown border. Pods develop lesions similar to stems and are often associated with twisting and distortion. Infected seeds are often malformed and show brown lesions with an occasional pink spore mass.
Seed coats can carry anthracnose spores without any visible symptoms.
Infection cycle Initial infection comes from fungal spores or mycelium carried on or in the seed. The fungus can survive for up to two years on the seed and possibly longer under some conditions. Seedlings emerge from infected seed and may develop lesions on the root, hypocotyl or cotyledons. After a few days, these lesions produce an abundance of spores which are spread through the crop by raindrops. The vast majority of spores are only spread a few metres, but a few travel further when raindrops are blown by gusting winds.