Minnesota Plant Diseases. 223 



Grain swollen in this manner requires the drill to be set 

 somewhat wider to permit the usual amount of seed to be sown 

 per acre. [Indiana Ex. Sta. Bull. 77 1899.] 



This has been found a very successful, safe a.nd cheap 

 process for combating smut. Xot all smuts are, however, pre- 

 vented by this treatment. Corn smut and loose smut of wheat 

 are not affected by it. It is undoubtedly, however, effective 

 against the smuts mentioned above. This method has advan- 

 tages over the hot-water method in the smaller degree of skill 

 required in handling. The seed can be left in the solution an 

 hour or more over the specified time without much injury, but 

 the prescribed two hours are usually sufficient to kill the spores 

 of the fungus. Oats require more of the solution than wheat 

 since they do not give access through the hulls so readily. "If 

 seed is kept long after treatment care must be taken that it 

 does not heat, otherwise no harm or disadvantage will result. 

 Professor Bolley, from some preliminary trials, estimates that 

 when sown soon after treatment it will be necessary to set the 

 drill for three and a half bushels of oats per acre if the equivalent 

 of two and one-haW bushels of the dry seed is desired, and with 

 wheat must be set for one bushel and eighteen quarts per acre, 

 if desired to sow one bushel and four quarts." [Indiana Ex. 

 Sta. Bull. 771899.] 



The same formalin solution can be used three or four times 

 but the seed must be left longer in each successive treatment 

 since the solution weakens. Formalin is not a violent poison, 

 so that the handling of this solution or that for the potato scab 

 is not at all dangerous for the operator. Special machines for 

 thorough immersion and rapid handling with the formalin solu- 

 tion have recently been placed upon the market. 



(B) For potato scab. 



''The formalin treatment of seed potatoes practically frees 

 the crop from scab, with slight expense and trouble. 



"Add one-half pound of formalin to 1 5 gallons of water and 

 immerse the seed tubers for not less than two hours. If the 

 potatoes are not much sprouted a longer wetting is advanta- 

 geous. After removing from the solution, cut and plant as 

 usual." [Ind. Ex. Sta. Bull. 771899.] 



