40 



IMPROVING THE QUALITY OF WHEAT. 



There has long been a desire manifested b}^ workers in this field to 

 establish some definite relation between the specific gravity of the 

 wheat kernel and its composition, or at least its nitrogen content. 

 Very contradictory results have been obtained by several experi- 

 menters, and little progress has been made. 



It is true that the various- chemical constituents that go to com- 

 pose the wheat kernel have different specific gravities, and as those 

 of the carbohydrates are all less than those of the proteids it 

 might be argued that a wheat having a large proportion of proteid 

 material would have a low specific gravity. However, the specific 

 gravity of the ash is so much greater than that of any other constit- 

 uent and the ash in wheats from different soils and climates varies so 

 much that these factors completely prevent the establishment of a 

 definite relation. The size and number of the vacuoles also influence 

 the specific gravity. 



In general, it may be said that as between kernels of the same 

 variety grown in the same season and upon the same soil, the specific 

 gravity is inversely proportional to the nitrogen content. 



CONDITIONS AFFECTING THE PRODUCTION OF NITROGEN IN THE GRAIN. 



So far as the writer has been able to ascertain there is no literature 

 bearing directly upon the conditions affecting the production of 

 nitrogen in the grain of wheat. 



Regarding high nitrogen in the wheat crop as arising merely from 

 failure on the part of the kernel to develop fully, it would seem that 

 a high percentage of nitrogen would inevitably be accompanied by 

 a small production of nitrogen per acre. This, however, does not 

 always appear to be the case. 



Taking, for instance, the yields of wheat obtained by Lawes and 

 Gilbert" for a period of twenty years, which they divide into two 

 periods of good and of poor crops, each covering ten years, we have 

 the following figures : 



Seasons. 



Good crop seasons. 

 Poor crop seasons. 



Average 

 yield of 



grain per 

 acre 



(pounds). 



1,833 



1,740 



Weight 

 per liushel 



Yield of 

 nitrogen 

 per acre 



- IN Ut'l ill 1 C 



(pounds), (j^ounds) 



60.2 

 57.1 



28.0 

 29.8 



It will be noticed that the largest production of nitrogen per acre 

 was in those years in which the weight per bushel and the yield per 

 acre were least. 



Of course this is not always the case, but that it should occur at 

 all is an indication that the conditions that make for high nitrogen 



« On the Composition of the Ash of Wheat Grain and Wheat Straw, London, 1884. 



