WHEAT 127 



ADAPTATION 



115. Climatic adaptation. — The wheat plant has a wide 

 climatic adaptation which in no little measure is responsi- 

 ble for its world-wide importance. If it were a plant 

 adapted only to certain restricted climates, it never could 

 have gained the place of preeminence which it now holds 

 among the nations of the world. In a general way, how- 

 ever, the world's wheat crop is grown in regions of cold 

 winters. Exceptions to this are to be found in India and 

 Egypt and in California. Wheat, for its best develop- 

 ment, requires that the plants make their early growth 

 during the cool part of the growing season. This is true 

 for both fall and spring varieties. If planted in the season 

 of the year when early growth is made during hot weather, 

 little stooling results and low yields are secured. While 

 wheat has a wide climatic range, climate has a marked 

 influence upon the quality of it. The division of the 

 United States into wheat districts, which has just been 

 discussed, has been due largely to the influence of climate 

 in the various sections of the country upon the physical 

 character of the grain. Wheat of the best quality is pro- 

 duced in sections having a cool and rather wet growing 

 season during the early life of the plant, followed by rather 

 hot, dry, sunshiny weather during the ripening period. 

 When these conditions prevail, the largest yields are se- 

 cured and the grain is of the best quality. Under these 

 conditions of growth the kernels are rather hard and 

 flinty and contain a relatively high percentage of protein 

 and low percentage of starch. In sections where rainfall 

 is plentiful and damp weather prevails during the ripening 

 period, the kernels are soft and starchy, containing a 

 relatively high percentage of starch and low percentage of 



