Several soilborne fungi, including Rhizoctonia spp. and water molds such as Pythium, thrive under wet soil conditions. Infected roots become soft, mushy, darkened, and decayed. Water mold fungi also cause "damping-off," the death of seedlings that collapse at the soil line under damp conditions. More mature plants infected with Pythium grow slowly and may gradually decline, exhibit terminal dieback, and die.
Solutions
Prevent damping-off diseases by preparing the site well before planting and providing appropriate cultural care, especially proper irrigation. Solarizing the soil before planting can reduce Pythium and Rhizoctonia fungi.
