10 BULLETIN 734, U. S. DEPARTMENT OF AGRICULTURE. 



are described as in use by the Department of Agriculture under tho 

 United States Grain Standards Act, or it may be estimated by means 

 of the so-called wild-oat kicker. 



Experiments were made to remove nematode galls as separable 

 foreign material (dockage) in the grain-standardization laboratory 

 of the Bureau of Markets by both methods. Using the oat-kicking 

 machine, only about one-eighth of the total percentage of the galls 

 were removed as easily separable foreign material, the others re- 

 maining behind in the sound wheat. By means of the standard 

 sieves, i. e., the fine-seed sieve, the buckwheat sieve, and the small 

 chess sieve, a somewhat greater percentage was removed. Even 

 with these three sieves, however, from 65 to 70 per cent of the galls 

 remained in the wheat as foreign material other than dockage. 



Experiments were also made to remove the galls by vigorous 

 fanning. By r this method, with a fan revolving 850 times per 

 minute, a still larger percentage was removed. Nevertheless 40 to 

 •45 per cent of the total galls remained. With still harder fanning 

 a greater quantity no doubt could be removed, but this would result 

 in the removal also of a greater quantity of sound wheat. 



Mills equipped with wheat washers and driers which are specially 

 devised to clean smutty wheat can eliminate these galls almost 

 entirely by floating them out, as they are lighter than sound wheat, 

 with a specific gravity of 0.8125. 



From a grading standpoint the presence of these galls in the 

 grain also reduces the weight per bushel, an important item in deter- 

 mining the grade of grain. It is readily seen that a farmer with 

 such galls in his load of wheat will be subjected to heavy penalties. 

 First, the separable foreign material is assessed as dockage, and later 

 the grade may be reduced because of the remaining foreign material 

 other than dockage. 



Knowing the pathological significance of these kernels, the ques- 

 tion might also be raised whether such wheat should not be regarded 

 as similar to wheat infested with garlic, onions, weevil, or smut, 

 and placed in a class by itself. 



The amount of flour which can be obtained from a bushel of 

 wheat is of prime importance to a miller, since flour is the most 

 valuable mill product. Any impurity which reduces the yield of 

 flour obtained in milling wheat or lowers the quality of the flour has 

 a direct bearing on the milling value and should receive considera- 

 tion in the grading of the wheat. Any factor which appreciably 

 injures the color of flour will result in a product of low grade or in a 

 reduction of the purchase price. 



Chemical analysis of the nematode galls by the Bureau of Chem- 

 istry is given below in comparison with an analysis of sound wheat 



