DISEASES OF WHEAT 161 



mentioned above. The grain is first soaked four hours 

 in cold water, and set away in wet sacks for four 

 hours more. It is then immersed for five minutes 

 in water at 132 F. Some of the seed is killed by the treatment, 

 and one-half more must be sown per acre. It has been claimed, 

 however, that no sure method of destroying loose smut is known, 

 and that the only available relief at present is to obtain clean 

 seed from a smut-free district. 1 



Results and Expenses. These remedies seem to be entirely 

 efficacious, and if properly and universally applied, there is no 

 reason why smut should not be practically eradicated from the 

 wheat fields. Before the nature of smut was fully understood, 

 one of the unexpected results of treating it was an increase 

 in yield greater than the result of merely replacing the smutted 

 heads with sound ones. This was explained when it was learned 

 that smut was often present in the straw even though it did 

 not reach the heads. Usually the increase in yield is two or 

 three times as great as the visible smut, but may be six or 

 more times as great. The methods of treatment are inexpen- 

 sive. In the hot water method the cost is practically only the 

 labor required. In some of the other methods the cost of 

 chemicals is little more than would pay for the labor in the 

 hot water treatment. Liquid formaldehyde, which is used quite 

 extensively in the Northwest, is found very effective, and costs 

 only from three-fourths of one cent to two cents per acre. The 

 treatment by sprinkling and shoveling is cheaper than dipping. 



Losses continue in spite of the fact that it has often been 

 demonstrated that smuts are controllable. During the year 1902 

 wheat smut caused a loss of 2.5 million dollars in the state of 

 Washington alone. In the following year smut destroyed from 

 10 to 50 per cent of the wheat in parts of Wisconsin. At 

 Winnipeg 3 to 6 per cent of the wheat offered for sale during 

 1904-5 was rejected on account of smut, and in 1905 as high as 

 75 per cent of the wheat was destroyed by smut in parts of 

 North Dakota. While seed wheat is very commonly treated 

 for smut, these losses show that there is still need for more 

 educational work. It is necessary to demonstrate repeatedly 

 the efficacy of the treatments in order to secure their adoption 

 by the conservative farming element. This element continues 

 1 Freeman, Minn, Plant Diseases (1905), p. 297. 



