all above ground parts of the pea plant and all growth stages are susceptible to "ascochyta pisi." the fungus overwinters in seed, soil, or infected crop residues. infected crop residue is the primary source of infection in the main pea producing areas. the fungus survives on seeds and in the soil as resting spores, called chlamydospores. the seed to seedling transmission rate is low. infected seeds turn purplish-brown and are often shriveled and smaller in size the pathogen survives as hyphae in the seed coat and embryo. new disease is established when spores of the fungus are carried to a new, healthy crop by wind or rain splash. these fungal spores then penetrate the leaf. in the spring, it produces conidia in pycnidia. the release of these spores begins in spring and can continue into the summer if moist conditions persist. the conidia are spread short distances by wind and rain. disease can also be established by planting infected seed. symptoms appear within 2–4 days after initial infection.