Hot Water Treatment for Smut ol7 



the time of filling- and ripening and since it had a week more to act on 

 the treated wheat the grain was considerably shrivelled and really in- 

 ferior to the untreated wheat. The farmers blamed the treatment for 

 the trouble. 



It was noticed at first that certain weeds like cockle and rye would 

 often be killed by the treatment. This led to rather false hopes for the 

 treatment and some county agents went so far as to recommend the 

 hot water treatment as a means of ridding the wheat of cockle. We 

 have found, however, that this cannot always be depended upon. In 

 Posey County it has been found that a treatment of 15 minutes at 

 130°F. is more effective in killing cockle and that it will not materially 

 injure the wheat more than the ten minute treatment. Experiments in 

 treating cockle seed have shown that one controlling factor is the length 

 of time that it is presoaked. With the cockle seed used, it was found 

 that after 12 to 24 hours of soaking the germination was reduced very 

 materially by the treatment. It seems, too, that fresh cockle seed is 

 more susceptible to injury than old seed. 



Without question the treatment will control the loose smut but 

 there are certain factors which have been found to prevent a perfect 

 control. These are: 1. Insufficient presoaking of the seed; 2. Imper- 

 fect heating of the seed due to excessive amounts of wheat in the sack 

 or the drum; 3. An incorrect thermometer, registering too high so that 

 the actual temperature of the water was below 129 °F. The stinking- 

 smut, however, is not always controlled. This is apparently due to the 

 inability of the heat to kill the spores in the center of the smut-filled 

 seed, followed by the subsequent breaking of these spore masses, which 

 results in the distribution of viable spores over the wheat. In Porter 

 County in 1922 there was one field where the treated wheat had 10 

 \.^L cent of stinking smut and the untreated part about 12 per cent. 



Changes made in Hie field applications. The original recommenda- 

 tion for eradication of loose smut, given by Freeman and Johnson in 

 bulletin 152 of the Bureau of Plant Industry, and at first followed in 

 Indiana, was as follows: Treat enough wheat for a small seed plot, 

 about five bushels, and select the seed for the next year's crop fi-om this 

 plot. The first objection to this program came from the farmer. He 

 could not or would not keep this small area separate from the rest of 

 the wheat. Usually it was necessary to plant this patch in a larger 

 field and when it came to cutting this separately and hauling it to the 

 threshing machine separately the trouble began. The farmers who had 

 been convinced of the value of the treatment treated enough seed for a 

 whole field and supplies of supposedly smut-free wheat began to appear. 

 With the advent of wheat certification, which calls for practically smut- 

 free wheat, the treatment became more popular. It soon became evident, 

 however, that using wheat from a smut-free field did not guarantee a 

 smut-free crop owing to the fact that the spores could easily be blown 

 from neighboring or even distant fields. This showed the fallacy of 

 recommending the seed plot method or even separate fields of treated 

 wheat and also seems to be one of the factors which has been retarding 

 the spread of the practice. The farmers feel that it is useless to treat 



