250 



Nature- Study Agriculture 



Damping 

 off 



Mildew 



Smuts 



A fungus often attacks the stems of young seedlings 

 in the nursery, making them rot off at the surface of the 

 ground ; such rotting is known as " damping off." 

 The danger from this fungus is lessened by keeping the 

 ground as dry on the surface as possible. Bordeaux 

 mixture may be used as a spray. 



For mildew, a good remedy is flowers of sulfur. It 

 should be dusted on the plants when the dew is on, 

 so that it will stick. Repeat the dusting every ten days 

 if necessary. 



There are different kinds of smut of wheat, oats, and 

 barley, but most of them can be prevented by soaking 

 the sack of seed grain for ten minutes in a barrel of 

 formalin, one pint to thirty gallons of water, or by 

 sprinkling the grain with formalin as shown in Figure 

 200. Smut of corn cannot be prevented by disinfect- 

 ing the seed. Gather and burn all stalks that have 

 smut on them, before the spores ripen and are scattered 

 by the wind. 



Experiments and Observations 



1. Heat the same dish of milk to boiling every day for several 

 weeks. The bacteria are killed and the milk remains good. 



2. Find as many different samples as you can of mold, mildew, 

 plant rust, and smut. Examine them with a hand lens or micro- 

 scope. 



3. Make and use Bordeaux mixture, following directions that 

 have been given. 



4. Disinfect seed potatoes with formalin. 



References 



"Cultivation of Mushrooms." Farmers' Bulletin 204. 

 "Some Facts about Malaria." Farmers' Bulletin 450. 

 "How to Prevent Typhoid Fever." Farmers' Bulletin 478. 



