CORN PESTS AND DISEASES 287 



sis shows that it is richer in protein than corn, oats or 

 clover hay, and is also high in carbohydrates. It con- 

 tains about four per cent of sugar, which may help to 

 make it palatable. It has been thought that the spores 

 pass through the animal without impairing their power 

 of germination, but this, like many other current views 

 regarding corn smut, is found by trial not to be true. 

 A concise statement regarding present knowledge 

 of the action of corn smut upon animals would be, that 

 it is a highly nutritive food, quite harmless, except 

 when eaten in excessive amounts, and then only rarely. 

 The small quantity of a narcotic-like substance which 

 it contains may under all ordinary circumstances be 

 ignored. 



CONTROLLING OR ERADICATING THE DISEASE 



In the spread of corn smut in the field, assuming 

 that careless husbandry has permitted smut masses to 

 remain undestroyed, thus providing an ample source of 

 infection, the most important factor is that of the 

 weather. A damp atmosphere, cloudy days, and gentle 

 winds furnish ideal conditions for the rapid spread of 

 the smut. Under such circumstances the delicate sec- 

 ondary spores are wafted about without loss of vitality, 

 and effect an entrance into the corn plant at any vul- 

 nerable point with little danger of desiccation. 



Observation has shown that periods of dull, sultry 

 weather were followed in about two weeks by out- 

 breaks of smut. A rain storm, however, checks the 

 spread of the smut, for it washes the spores from the 

 air and the surface of the plants into the ground, where 

 they come to naught. A rainy season, therefore, may 

 be less favorable to the growth of smut than a dry 

 season in which dewy nights are frequent. 



From a knowledge of the life history of the corn 

 smut fungus only two courses seem open at present for 



