CHAPTER VIII 

 CEREAL IMPROVEMENT SELECTION 



ALL improvement of cereal plants is fundamentally a 

 selection of the best individuals, whatever the method 

 employed. Even the introductions discussed in the pre- 

 ceding chapter are only thoroughly accomplished after 

 years of acclimatization, which is virtually adaptation 

 through selection, natural or artificial. Hybridization 

 attains no end without intelligent selection of the prog- 

 eny. On the other hand, much of the work commonly 

 called selection is practically a sorting of mixtures. 

 Selections proper may be made en masse or by separate 

 individuals. The subject will be discussed, therefore, 

 under the headings : (1) sorting and roguing of mix- 

 tures, (2) mass selection, and (3) pure line selection. 



176. Sorting. Almost all the common or standard 

 varieties of cereals are aggregations or mixtures of two or 

 more distinct varieties or strains. The first step in selec- 

 tion, therefore, is a sorting out of these strains. Sorting 

 is usually accomplished by hand picking the seed or by 

 a separation of single plants in the sheaf. 



Introduced cereals are particularly likely to be mixed, 

 as they are usually obtained because of resistance to 

 severe climatic conditions, in regions where primitive 

 agricultural methods are practiced (see 75). As already 

 mentioned (161), the Chul wheat, when introduced, had 

 light amber and dark amber kernels, and, on planting, 



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