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Smut in Grain. 

 What the Smut is. 



Wheat smut is eau>>ed by a small plant wliieh steals its food from tlie 

 wheat plant. The smut plants are distributed by the fine, black powdery 

 grains of smut which cling to the seed wheat. Even when the wheat 

 appears to be clean, they may be present in the grooves in the side of the 

 grain or in the tuft of hairs at one end. When the farmer plants the wheat 

 he also plants the smut. As the smutted kernel goes into the ground it 

 carries with it several grains of smut. After being planted, the wheat grain 

 grows and brings forth a small plant. So also the .smut plant germinates and 

 sends out a fine thread-like plant so small that it cannot be seen with the 

 unaided eye. The smut plant soon produces small threads, which penetrat*; 

 into the small wheat plant through its soft and delicate skin. After a few 

 days, however, at about the time that the wheat unrolls its first leaf, its skin 

 gets too hard to be penetrated by the smut, so that if the wheat has escaped 

 thus far it is no longer in any danger from the smut. 



If the smut has penetrated the wheat skin during its danger period it 

 continues to grow in the wheat plant up through the stem. About the time; 

 that the wheat plant makes its seeds the smut .sends its thread into the wheat 

 kernel. As fast as food is stored up for the young wheat plant, the smut 

 steals it and replaces it with its smut grains. 



In the covered or stinking smut of wheat only the inside of the kernel is 

 removed by the smut and a shell is left around it, but in the loose smuts, as 

 for example the loose smut of oats, the whole kernel is destroyed iind the 

 spores are left expo.sed to be blown about by the wind. 



The wheat kernels which have been smutted are broken in handling or 

 iu threshing, and the smut grains are thus scattered on to new wheat, and 

 are ready for the next year's planting. Very evidently, the only way in which 

 this disease can be reached and the smut plants killed is by treating the seed 

 wheat with something whicli will kill the smut grains, but which will not 

 injure the wheat. 



Hard Smut {Tillctia curies). Fig. 18b. 



(a) A " Bunted' 



(c) A longl- 



Tillctia ciirirs (Till.) and T. Iwvis (J. Kuclin.) 



grain of wheat; (()) .V traverse section of tlie same; 



tudinal section. (.\11 enlarged five diameters.) 



The diseases of wheat known generally in North xVmerica under the name 



of " Bunt," " Hard Smut," or one of the other designations mentioned above, 



*re due to the ravages of two parasitic fungi belonging to the family Tilletia. 



G 



