300 Gardening , 
THE DAMPING-OFF DISEASE 
Several kinds of fungi attack young seedlings and cause 
them to topple over and die. Heavy losses from this 
cause often occur in seed beds and cold frames. Usually 
all the plants in an area are attacked and killed, leaving 
bare patches. In some cases the plants survive until 
they are placed in the field, but even then they grow 
poorly and often die. 
The fungi which cause damping off can live on decay- 
ing organic matter in the soil, they can attack the living 
tissues of seedlings, and they can continue to feed on the 
plants after they are dead. Certain of these fungi are 
practically always present in soil which is rich in organic 
Fic. 168. Lettuce seedlings affected with the damping-off disease. The plants 
just above the center of the picture are falling down and rotting, 
