HANDLING WHEAT FROM FIELD TO MILL. 5 



ural color or " bloom " and giving them what is termed a " bleached " 

 appearance. Even when well shocked and protected by a cap bundle, 

 continued exposure brings on a change in the outer bundles, which are 

 only poorly i:)rotected at best, and after a shock has stood a month, or 

 even less, it is found that as a result of this weather damage samples 

 of wheat taken from the outer portions of the shock are at least a 

 grade poorer than those taken from the inner part of the same shock. 

 In thrashing, this poor wheat is mixed with the good and the grade 

 of the whole is lowered. Such exposure and the resulting change in 

 appearance have a direct and immediate effect upon the market value 

 of the grain. The grade that is given to wheat upon the terminal 

 markets depends to-day almost wholly upon its appearance, condi- 

 tion, and test Aveight per measured bushel. AMien the natural color 

 or " bloom " of the kernel has been destroyed by rain and sun while 

 standing in the shock and the increase in moisture content has caused 

 a corresponding decrease in the test weight per bushel, the grade 

 given is lower than it would be if this same wheat were marketed 

 in good condition without deterioration resulting from exposure to 

 the weather. It is common knowledge among farmers that wheat 

 standing in the shock may readily lose a pound per bushel in test 

 weight on being exposed to a heavy shower. This is especially true 

 where the wheat has been carelessly shocked and is not protected by 

 cap bundles. 



RELATION OF MOISTURE CONTENT TO TEST WEIGHT. 



Preliminary tests of the relation between moisture content and 

 test weight per bushel in wheat have been made in several of the 

 Grain Standardization laboratories of the Bureau of Plant Industry, 

 and the results of these tests indicate that while the rate of increase 

 in moisture content is not accompanied by a constant rate of decrease 

 in test weight per bushel, nevertheless a close relation exists between 

 the two factors. Furthermore, the data secured in these preliminary 

 tests support the belief that Avhen once the moisture content has been 

 materially increased and the test weight per bushel correspondingly 

 lowered through that cause there is not a corresponding reverse 

 action ; or, in other words, although wheat that has absorbed a high 

 percentage of moisture may be again dried out to approximately its 

 former moisture content, it regains comparatively little of the test 

 weight lost. This applies especially to wheat when thrashed from the 

 shock. 



EFFECT ON SOUNDNESS OF EXPOSURE TO WEATHER. 



In addition to causing the bleached appearance and lowering the 

 test weight, the exposure of wheat to rain and sun while standing in 

 the shock causes many of the kernels to sprout, and sprouted wheat 



[Cir. 68] 



