578 



PLANT BREEDING 



This method of selection is productive of good results, but 

 has some disadvantages. It requires much time and labor as 

 well as the use of much ground. Since each crop is grown 

 from seed furnished by many plants selected the previous year, 

 the progeny of many plants are involved and the yield of a crop 



m 



FIG. 487. Dakota Amber Sargo, a strain that matures much earlier and 

 is more drought-resistant than the South Dakota No. 341 from which this 

 new strain was produced by selection. After Dillman. 



is the average yield of the descendants of many plants varying 

 in capacity and heritage for high yield. Many of the plants 

 in the selection are likely to be heterozygous for the character 

 and consequently will not breed true. Races obtained by this 

 method of selection usually lose their desirable features unless 

 selection is continued. 



Pedigree Culture. The value of pedigree cultures was well 

 demonstrated by De Vries and Mendel. In the method of 

 selection by pedigree cultures, a single plant is selected, and 

 from its progeny, which are carefully guarded, the best indi- 



