132 THE SOILS AND CROPS OF THE FARM. 



wheat germinates. The seed is not infected, and no 

 treatment of it would be of any avail. 



Black, or loose smut, is a disease afPecting the ker- 

 nel of wheat and other cereals and is caused by a 

 aicroscopic plant of a somewhat different nature from 

 rust, known as Ustilago Tritici. 



In black smut the whole kernel and even the chaffy 

 parts are reduced to a black powder, as is commonly 

 seen in oats. The black powder is the fruiting stage 

 of the smut and is composed of myriads of spores. 

 These spores are blown about by the wind and fall on 

 the ground, when they are ready to infect a succeed- 

 ing crop. More or less remain sticking to the unin- 

 fected ben-ies, which when the seed is sown causes 

 the disease again. 



The remedy is obvious and complete. Sow on 

 ground not previously infected and sow seed which 

 has not come in contact with the smut, or sow with 

 seed on which the smut has been killed. 



The same methods which are employed in purify- 

 ing smutty grains, in the case of stinking smut, given 

 below, are recommended by some experimenters for 

 this form of smut, but their efficacy is denied by 

 others. 



Stinking smut or bunt is caused by either of 

 two fungi, Tilletia foetena and T. tritici, some- 

 what related to the loose smut above described. 

 This form of smut instead of reducing the berry to a 

 powder and blowing about is retained within the coat 

 of the berry, often through all the processes of har- 

 vesting and marketing. 



The infected kernels when ripe are more or less 

 swollen and of a brownish color. As they are larger 



