IMPORTANCE OF THE CROP 51 



United States to make it worth while to attempt an enumera- 

 tion of them. Corn is so easily changed by selection that 

 one may not be able to recognize a well-known variety after 

 some one else has been growing and selecting it for some time. 

 This is especially true if it has been grown under different soil 

 and climatic conditions from those in which he has seen it 

 grow before. On this account, varietal names are not impor- 

 tant, but types of corn and their adaptability to various 

 conditions must be thoroughly understood by practical corn 

 growers. (See Selection of Corn, Sections 121-132.) A few 

 of the important and widely distributed varieties of corn are 

 Reid's Yellow Dent, Boone County White, Silvermine, Gold- 

 mine, Legal Tender, Silver King, Minnesota No. 13, and 

 Wisconsin No. 7. 



IMPORTANCE OF THE CROP 



58. World Production. Corn is a tropical plant that can 

 withstand very little frost. It seems best adapted, how- 

 ever, to the temperate zone and it is here that it reaches its 

 most perfect development. The leading countries in the 

 production of this crop normally are the United States, 

 Austria-Hungary, Argentina, Russia, Egypt, and Australasia, 

 in the order named. According to the Bureau of Crop Es- 

 timates of the United States Department of Agriculture, the 

 average annual world production of corn for the five years 

 from 1909 to 1913 was 3,800,000,000 bushels, of which 71 

 per cent was produced in the United States. The figures 

 from 1909 to 1913 are given in preference to those for later 

 years, which are of necessity incomplete. 



59. Production in the United States. The average acre- 

 age, production, yield, and value of corn in the different 

 states for the years from 1908 to 1917 are shown in Table 

 III. The relative production is shown graphically in Figurel5. 



60. Relative Importance. Corn is grown on a larger acre- 

 age and produces a larger total yield than any of the other 



