EARLY CULTURE OF CORW 83 



59. Natural selection and acclimatization in producing 

 varieties. — It is well known that each region of the United 

 States has corn of a type more or less peculiar to that 

 section. For example, in the Gulf States, corn grows 

 very tall, frequently 15 to 18 feet, with ears 6 or 8 feet 

 from the ground; in the Corn Belt States the plant is 

 about two-thirds as high ; while along the Canadian border 

 the height is 5 to 8 feet, and ears are often less than 2 feet 

 from the ground. Also the growing season will vary from 

 200 days in the South to 80 days in the North. If a 

 variety of corn be moved from one section to another, it 

 will become from year to year more like the native corn 

 of the region. 



It is not known how much of this change may be due 

 to actual modification of the plant by environment, but 

 it is probable that it is brought about chiefly through 

 wide variations and through both natural and artificial 

 selection. When a varietj^ is moved from one climate or 

 soil to another, it does not yield so well the first year as 

 later, when it becomes " acclimatized." When planted 

 first in the new location, there are certain plants much 

 better suited than others to the new conditions. These 

 would produce the best ears and be selected for seed, thus 

 preserving the best-adapted type. An excellent example 

 is cited from Nebraska,* where a variety of corn from 

 Iowa was grown in central Nebraska for two years and 

 as a result decreased about 12 inches in height, while the 

 ear was almost 8 inches lower ; the yield of grain, how- 

 ever, increased. 



If the same variety be v/idely distributed and grown 

 for a few years, and seed again collected for compari- 

 son under the same conditions, it will be found that 



1 Nebr. Agr. Expr. Sta., Bui. 91 ; 29, 



