6 



BULLETIN 328, U. S. DEPARTMENT OF AGRICULTURE. 



winterkilling as wheat. Baking tests with, flour milled from wheat 

 samples containing different percentages of rye showed detrimental 

 effects on both the color and the texture of the crumb when above 3 

 per cent of this impurity was added to the wheat. 



Examinations of samples of flour milled from wheat which con- 

 tained various percentages of rye showed the presence of a consider- 

 able number of grayish and greenish yellow specks, especially in the 

 samples containing more than 3 per cent of this ingredient. 



Wheat containing a 3 per cent admixture of rye will yield a darker 

 colored flour, showing quite distinctly toward the tail of the mill. 

 When rye is milled alone about 48 per cent of flour is obtained, as 

 shown in Table III (p. 10). Rye flour does not bolt freely, but 

 when blended with wheat in small amounts it seems to cause very 

 little trouble in bolting, since the wheat flour aids the rye flour in 

 passing through the bolting cloth. The fact that the flour yield 

 was but slightly reduced even in samples of wheat with 5 per cent 



Fig. 2.— Wheat containing 6 per cent of corn-cockle seed and 8.7 per cent of other foreign matter, as 

 delivered at a country elevator. (Natural size.) 



or more of rye would indicate that a large proportion of the rye 

 flour bolted through with the wheat flour. When wheat containing 

 10 per cent of rye was milled into three grades of flour, the injurious 

 effects of rye were most pronounced in the second-clear flour, as 

 evidenced in the baking results given in Table VI (p. 16). 



CORN COCKLE. 



Corn cockle (Agrostemma githago) is an annual prolific weed, the 

 seed of which is rough, black, and of such a shape and size as to 

 make it difficult to separate from wheat. It is very common, being 

 widely distributed over the United States, and is especially abundant 

 in the sections producing soft red winter, spring, and durum wheats. 

 It is not an uncommon occurrence for wheat to contain 1 or 2 per 

 cent of this'weed seed, and occasionally 5 or 6 per cent of corn cockle 

 is present in the'grain as marketed (fig. 2). The presence of 1 or 2 per 

 cent of corn cockle in wheat is likely to lower the grade or price given 

 the farmer and will lower the baking qualities of the flour. The fact 



