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 



FIG. 1 68. Lettuce seedlings affected with the damping-off disease. The plants 

 just above the center of the picture are falling down and rotting. 



