A disease of seedlings encouraged by cold wet soil and crowded conditions. In pre-emergence damping-off the germinating seed rots before the plumule breaks through the soil surface. In post-emergence damping-off the seedlings rot at soil level and then collapse and die. Damping-off is caused by numerous soil-inhabiting fungi including Fusarium, Phytophthora, Pythium, and Rhizoctonia (Corticium). Correct planting conditions, seed dressings, and the use of sterile soil in seed trays are the usual preventative methods. See also seedling blight. |
