Poor stands resulting from seed piece decay can be a major problem if cool, wet weather prevails immediately after planting. Several pathogens may cause seed tubers to rot before emergence.
Fusarium is the most common fungus responsible for seed piece decay. Soft rot bacteria often invade tubers infected with Fusarium, causing the seed to
rot very quickly. The late blight fungus (see page 41) and Pythium spp. (see page 79) may also cause seed piece decay.