8 BULLETIN 328, U. S. DEPARTMENT OF AGRICULTURE. 



addition to the regular grain-cleaning machinery commonly found 

 in mills, is that of floating it out with wheat washers, specially 

 devised machines for cleaning smutty wheat. Since installing this 

 equipment is expensive, few mills have such facilities, and they must 

 depend on the ordinary grain cleaners, which remove but a small 

 percentage of the kinghead seed, often present in quantities as high 

 as 3 or 4 per cent. Unless wheat that contains large amounts of 

 kinghead seed is mixed with a sufficient quantity of clean wheat to 

 reduce the percentage of kinghead to a minimum, the flour produced 

 will be of inferior quality. Such flour contains black specks, which 

 injuriously affect the quality of the bread both in color and texture. 

 The writer secured in a country mill samples of flour milled from 

 wheat containing about 2 per cent of kinghead seed. Baking tests 

 of these samples showed that both the color and the texture of the 

 loaf were very seriously affected. When milled alone, kinghead seed 



Fig. 3.— Wheat containing 28 per cent of kinghead seed and 3.5 per cent of other foreign matter, as unloaded 

 from a wagon at a country elevator. (Natural size.) 



gave a very low yield (less than 16 per cent) of flour, which was dark 

 gray in color. The flour was readily reduced, the bulk of it being 

 made on the break rolls and the first reduction. On account of the 

 dark color of this flour, a mixture of 1 per cent of kinghead seed in 

 wheat when milled is noticeable in the flour. When wheat con- 

 taining 10 per cent of kinghead was milled into three grades of flour, 

 the injurious effects of this so-called inseparable ingredient were in 

 evidence in all grades, as shown by the results of the baking tests 

 given in Table VI (p. 16). 



Figure 3 shows a sample of spring wheat as grown and delivered to 

 an elevator by a farmer. This sample contained 28 per cent of 

 kinghead seed by weight, in addition to 2 per cent of rye and 1.5 per 

 cent of wild oats. On account of the excessive amount of this prac- 

 tically inseparable weed seed in the wheat, the price and grade were 

 greatly reduced, and, as with the sample which contained corn cockle, 

 a heavy dockage was assessed by the grain buyer. 



