14 BREEDING CROP PLANTS 



who gives to hybridization the major role in the production of 

 variations. Some serious criticisms have been made of this 

 hypothesis as an explanation of evolution. With the higher 

 plants, however, natural crossing has doubtless played an im- 

 portant evolutionary role. From the standpoint of the plant 

 breeder crossing is of much importance and it is the only generally 

 known means of producing variations of selection value that is 

 available as a practical method. In cross-fertilized species crosses 

 naturally occur followed by segregation, and recombination 

 follows. Selection isolates desirable genotypes. 



THE VALUE OF CROP IMPROVEMENT IN RELATION TO A MORE 

 EFFICIENT AGRICULTURE 



Maximum yields of crops can be obtained only when all 

 factors relating to the various phases of crop production are 

 favorable. The physical and chemical characteristics of the soil, 

 correct time and rates of planting, and crop rotation must be 

 considered. Recent studies have shown that there are marked 

 differences in the effect of different crops upon those that follow 

 them in the rotation. Of utmost importance is the necessity 

 that the crop be adapted to the soil and climatic conditions 

 in which it is to be grown and that profitable returns be obtained 

 on the basis of the cost of production. 



After careful consideration of those factors which go to make 

 up the home of the plant we turn our attention to the seed. The 

 fact that there are remarkable differences in final yields from 

 different varieties of the same crop is commonly known. We are 

 as yet only on the threshold of the possibilities of crop improve- 

 ment. Careful methods of seed inspection, registration, and 

 treatment to control diseases are necessary to the greatest 

 return from crop breeding. Education of the farmer will do 

 much to overcome the evils of exploitation by the unscrupulous 

 seed dealer or promoter who is anxious only to sell and make 

 a profit on his seed. 



The business of growing carefully bred seeds is one that needs 

 an appreciation of these and other factors in seed production. 

 No great amount of special training is needed to carry on this 

 work. To the careful worker who is willing to build up a reputa- 

 tion by actual merit of his seeds, the business of seed production 

 will prove a lucrative one. 



