294 THE ESSENTIALS OF AGRICULTURE 



383. Preventive treatment of smuts. In the smuts which 

 are carried from year to year by spores adhering to the seed, 

 smut infection can be prevented by some disinfecting treatment 

 which kills the spores and does not injure the grain for seed. 

 Treatment of seed wheat in water at a temperature of 132 de- 

 grees F. to 133 degrees F. for from ten to fifteen minutes, or 

 in a formalin solution composed of one pound of formalin to 

 forty-five gallons of water until every kernel is thoroughly wet, 

 destroys the spores. If the treatment is properly done, the seed 

 is not injured and the disease is prevented. Treatment for oats, 



FIG. 143. Corn smut 



The grains have become completely occupied and greatly distorted by smut. 

 (Photograph by E. C. Johnson) 



barley, and sorghum smuts are similar. The planting of seed 

 from a clean field, which has not been contaminated in smutty 

 sacks, bins, or machinery, will result in a clean crop. 



The loose smuts of wheat (Fig. 142) and barley affect not only 

 the kernels but the chaff, producing at heading time a sooty 

 mass of spores which are scattered by the wind. When these 

 spores lodge in the flowers of the wheat or barley, they ger- 

 minate and grow inside the developing seed. The wheat smut 

 infects only wheat ; the barley smut only barley. The presence 

 of smut in the seed cannot be detected, but when the seed is 

 planted and germinates, the smut grows also inside of the plant 

 until the head is ready to form, when in place of a sound head 

 a smutted head occurs. As the smut plant is inclosed within the 



