VARIATION OF PROTEIN CONTENT OF CORN 



By H. B. Arbuckle and O. J. Tiiies, Jr. 



I. Influence of Climate 



Corn is now the greatest feed crop in the United States, and is 

 relied upon for the production of most of the beef, mutton, and pork 

 marketed in this country, and exported to foreign countries. For 

 fattening butcher stock on the farms and in the big feed yards 

 corn is the most efficient food, but for breeding stock, and young 

 animals, it must be used with caution. Grains of higher protein 

 content, such as oats, soybeans, wheat (in form of bran) must supple- 

 ment the corn. 



Many attempts have been made to increase the protein content 

 of corn with a view to removing its deficiency, but despite all these 

 efforts the protein content of corn in general remains the same. By 

 careful seed selection some varieties have acquired the reputation of 

 possessing higher protein content, but after a few years it is found 

 that it has dropped back to its former standard. Hayes and Garber, 

 in 1919, completed some experiments extending through a period of 

 several years, in which, by self-fertilization, followed by crossing and 

 seed selection, they were able to increase the protein content as much 

 as two per cent, thus making it almost the equivalent of oats in 

 protein. The yields, however, were greatly cut down, and the corn 

 developed showed a tendency to revert to the lower protein stand- 

 ard. Such experiments, and other similar observations, raise the 

 question as to whether the protein content in a given variety of corn 

 is a fixed factor. 



If the protein does change, can this change be controlled? What 

 is the effect of climate, season, soil, fertilizer, tillage? 



The object of this investigation begun a year ago by the authors 

 is to determine, if possible, how certain conditions may modify the 

 protein content in a given variety of corn. This preliminary paper 

 presents the results of our first year's investigation of the effect of 

 climate. We have chosen three varieties of corn, and will super- 

 vise the seed selection each year. The first variety is a white corn. 

 Silver King, which has been grown for four years on the farm of 



[ 84 1 



