RELATION OF SIZE OF KERNEL TO NITROGEN CONTENT. 35 



The fact before referred to that both large and small kernels are 

 found on the same head of wheat is perhaps an argument against the 

 superior value of large seed. If the plant and not the seed is the unit 

 of reproduction, small seed from a plant whose kernels averaged 

 large size may be better than large seed from a plant whose kernels 

 averaged small size. 



On the other hand, there can be no doubt that the majority of the 

 kernels in the lot of heavy kernels would be from plants having large 

 spikes, and vice versa. This would give the kernels in the heavy lot 

 some advantage. Again, the advantage that the large kernel is sup- 

 posed to possess for seed may not be in producing a large kernel in 

 the resulting crop, but in giving the plant a better start in life, or 

 producing a more vigorous plant. 



RELATION OF SIZE OF KERNEL TO NITROGEN CONTENT. 



Richardson" has made a large number of analyses of wheats from 

 different parts of the United States. The weight of 100 kernels was 

 also determined in each sample. There can not be said to be any 

 constant relation between the nitrogen content and the kernel weight, 

 but in the main the large kernels have a lower percentage of nitrogen 

 than the small kernels, and inversely. 



Pagnoul* reports that in a test of eleven varieties of wheat there 

 was in the main a decrease in the percentage of nitrogen in the crop 

 a< compared with the seed when there was an increase in the weight 

 of 1,000 kernels in the crop as compared with the seed. 



The same investigator" again states that in an examination of 

 seventy varieties of wheat there was no constant relation between 

 the size of the kernels and their nitrogen content, but that in general 

 the varieties with small kernels were the varieties richest in nitrogen. 



Marek* separated wheat of the same variety into lots of large and 

 of small kernels. He found on analysis that the large kernels con- 

 tained 12.52 per cent protein and the small kernels 13.55 per cent 

 protein. 



Woods and Merrill ' made analyses of a number of wheats grown 

 in Minnesota and of the same varieties grown in Maine. The wheats 

 uniformly developed a larger kernel when grown in Maine. Grouping 

 five varieties raised in Minnesota and five raised in Maine, it will be 

 seen that with this increase in the size of the kernel there was a 



" U. S. Department of Agriculture, Division of Chemistry, Bulletins 1 and 3. 

 '' Abstract in Centrlb. f. Agr. Chem., 1893, p. 616, from Ann. Agron., 1892, p. 486. 

 c Abstract in Centrlb. f. Agr. Chem., 1888, p. 767, from Ann. Agron., 14, pp. 262-272. 

 'Abstract in Centrlb. f. Agr. Chem., 1876, from Landw. Zeitung f. Westfalen u. Lippe, 

 I 875, p. 362. 



Maine Experiment Station Bulletin 97. 



