Improving Plants by Selection or Breeding;. 



545' 



mofiey and give zest to the farm work. Riley, the Indiana farmer who 

 bred the Boone County White Corn (fig. 2), was an ordinary farmer, 

 not a scientific experimenter. Yet his variety is grown extensively over 

 a dozen of the great corn states and has added thousands upon thou- 

 sands of dollars to the valuation of the corn crop of the world. Many 

 of the standard varieties of our ordinary crops have been bred by our 

 farmers, and the time has come when such services to humanity will 

 be recognized and rewarded in history as are the noteworthy deeds of 

 other great men in other fields of human 

 industry. At the present time probably no 

 field of human activity offers greater op- 

 portunity for advancement and reward than 

 the field of agriculture and when pursued 

 with intelligence and energy, success is 

 almost certain. 



SOME OF THE PRINCIPLES 

 PLANT BREEDING 



OF 



o 



10 



c5 



C^^ 



Fig. 2. — Boone County Whi^e 

 Corn; on left car of se e t 

 type, on right ear of c.igi- 

 nal unsclected type. (From 

 Cyclopedia of American 

 Horticulture.) 



If one is to use the most comprehensive 

 methods of breeding, the operations become 

 very complex and few farmers would have 

 the time to undertake the work on so ex- 

 tensive a scale. No matter, however, what 

 methods of breeding or seed selection the 



farmer is pursuing he should be familiar with the general principles 

 involved, and it is the intention in this paper to outline the most funda- 

 mental principles, which, it is believed, should be understood by all 

 farmers. In this paper no attention will be given to hybridization in the 

 origination of varieties, as this field of breeding is too complex to be 

 pursued successfully by farmers generally. 



What arc variations? 



The fact that we are able to improve plants by selection depends 

 upon the occurrence of what are called variations. We are accustomed 

 to think of plants as very stable and uniform. As we casually look 

 fiver a field of Ox-eye daisies and admire their beauty, we distingui/ii 

 no apparent variability ; all seem to be alike. Nevertheless, if we examine 

 the plants carefully and study the different individuals we find that 

 each one possesses certain peculiarities. Some have large flower heads, 

 others small flower heads; some have very many rays or petals, others 

 18 



