BULLETIN 168, U. S. DEPARTMENT OF AGRICULTURE. 



Bureau of Plant Industry, United States Department of Agriculture, 

 have been designated as the standard on which the grades have been 

 based. Copies of this circular can be secured upon application to 

 the United States Department of Agriculture. This in no way pre- 

 cludes the use of other methods of making moisture determinations, 

 so long as s the results are corrected to conform to those secured by 

 the standard method specified. Figure 4 represents a sectional view 

 of the standard tester that is recommended. The United States 

 patent covering this tester has been donated to the people of the 

 United States, so that the tester can be used, manuf actured, or sold 

 by any citizen within the United States without the payment of 

 royalty. 



DAMAGED CORN. 



As shown in the grade classification (Table I), the grades 1, 2, and 

 3 may contain not to exceed 2, 4," and 6 per cent, respectively, of 



damaged corn, such as "cob-rot- 

 ten" corn, "blue eyes," etc., but 

 these first three grades shall not 

 include heat-damaged or mahog- 

 any kernels. Grades 4, 5, and 6 

 may contain not to exceed 8, 10, 

 and 15 per cent, respectively, of 

 damaged corn, a portion of which 

 may consist of heat-damaged or 

 mahogany kernels. The heat- 

 damaged or mahogany kernels 

 permissible ; \ a part of the dam- 

 aged corn sw!l not exceed one- 

 half of 1 per cent in No. 4 grade, 1 per cent in No. 5 grade, and 3 per 

 cent in No. 6 grade; but the total damaged in these three grades shall 

 not exceed 8, 10, and 15 per cent, respectively. 



Types of damaged kernels. — An attempt has been made to show in 

 natural colors by means of kernels numbered 1 to 26 in Plate I types 

 of kernels which should be classed as damaged. These types of 

 damage range from the badly "silk-cut" kernels, shown in No. 1 

 (front and back of same kernel), to the very badly "cob-rotten" 

 kernels shown in No. 26. These types also include badly shriveled 

 kernels which have failed to ripen (shown by kernels numbered 14 

 and 15). However, skeleton kernels similar to this type, when con- 

 sisting of nothing but the skin of the kernel or of such a character 

 that they would be removed by light blowing or fanning, should be 

 classed as foreign material and not as damaged corn. Types of such 

 skeleton kernels are shown in figure 5. 



Fig. : 



-Nest of two sieves and bottom pan used in 

 grading corn. 





