CHAPTER XXVII 



WHEAT CLIMATQ, SOILS, ROTATIONS, CUL- 

 TURAL METHODS AND HARVESTING 



THE wheat plant is very sensitive to soil conditions. It 

 is also much affected by climate, particularly as regards the 

 ease with which it succumbs to diseases, especially rust. 

 For these reasons there are vast areas in the cotton-belt 

 that cannot be made to produce wheat successfully. 



397. Climate. The range of climate under which 

 wheat is successfully produced throughout the world is 

 very wide. The bulk of the world's wheat crop, however, 

 is produced in regions having cold winters. The three 

 noted exceptions to this statement are the crops of Cal- 

 ifornia, Egypt, and India. In the Northern hemisphere 

 the wheat industry is gradually spreading northward, 

 first as spring-sown varieties which after much selection 

 and manipulation are sown with success in the fall. With 

 proper attention spring wheat can often be changed to 

 winter wheat in a relatively short time. Spring wheat 

 once grew over Iowa, Kansas and Nebraska, where only 

 winter wheat is now grown. This same change is taking 

 place in the Dakotas and Minnesota. These modifica- 

 tions, while partly due to changed cultural methods, show 

 also the great adaptability of wheat to unfavorable cli- 

 matic conditions. In the preceding chapter reference was 

 made to the influence of climate on the chemical and 

 physical constitution of the wheat kernel. The protein 



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