ascochyta blight of peas is caused by a fungus. more than one fungal species can cause this disease. other pathogens that cause ascochyta blight, besides "ascochyta pisi", include: "mycosphaerella pinodes", "phoma medicaginis var. pinodella", and "phoma koolunga". "mycosphaerella pinodes" is the only species that develops a sexual spore stage on infected residue. this stage results in the production of wind-blown ascospores. ascospores can be dispersed several kilometers. ascospore release begins in the spring and can continue into the summer if there is enough moisture. "didymella pisi" is the teliomorph stage of "ascochyta pisi"