The fungus overwinters in infected crop debris either inside of pycnidia or as mycelium. Primary inoculum originates from overwintering fungal structures (perithecia, pycnidia, and mycelia).
Fungal spores survive the winter by hiding in contaminated agricultural waste either inside pycnidia or as a network of mycelium. The initial infection source originates from dormant fungal structures such as perithecia, pycnidia, and mycelium.