412 



PLANT DISEASES 



and grain, as it does in wheat, and the covered smut remains 

 inside, destroying only the grain. The reduction in yield, due to 

 these diseases, sometimes reaches as much as 90 or 100 per cent 

 of the crop. 



The method of preventing these diseases is simple and usually 

 very successful. The seed grain may be treated with a solution of 



formalin, using one pint of full 

 strength formalin (40 per cent) 

 in forty gallons of water. The 

 seed should always be thor- 

 oughly wet by soaking about 

 ten minutes. This may be done 

 in loose sacks or may be done 

 by sprinkling the seed in large 

 boxes or wagon beds. If the 

 sprinkling method is used the 

 grain must be stirred thoroughly 

 during the process to be certain 

 that all parts are wet with the 

 formalin water. Formalin is a 



Pgood fungicide and kills the 

 spores. When wheat is affected 

 w I by the stinking smut this treat- 



f ment is not always successful, 



because some of the smut balls 



FIG. 287. Oats attacked by smut dis- 

 ease on left compared with sound oats on are not Wet through. It SUCh 

 right. (Agriculture and Life.) . , . . - ,. 



grain is poured into formalin 



water much of the badly affected grains will float and may be 

 easily separated from the good seed. Another method used for the 

 stinking smut is to treat the seed with hot water at a temperature 

 of about 130 F. The water should be kept at this temperature 

 for about ten minutes, and any grain which floats should be 

 skimmed off. 



Corn Smut. This is a very different disease from the smuts 

 which affect small grains. Large round or oval masses containing 

 black smut spores are found on the ears of corn. Often these take 

 the place of kernels on the cob. Tassels, leaves and stems are also 

 sometimes affected. 



It is believed the disease lives over winter in the soil and may 

 be spread to the new crop from the soil or from manure spread 

 in the field which contains the spores from the feed lot or barn. 



