508 PLANT BREEDING 



breeding power of each parent plant is measured in terms of 

 the average of its progeny. A select head is chosen from each 

 of several of the best plants in every plot, and the seed from 

 these is saved. 



A third year and a fourth year hundred-group plots are sown 

 and managed as just described, and at the end of the period the 

 most promising varieties are taken to field trials. Here they 

 are tested, under ordinary farm conditions, in comparison with 

 the wheats commonly grown, and the best, if it stands severe 

 milling tests, is then propagated for distribution, under suitable 

 designating numbers, to wheat growers throughout the state. 



The rate at which new varieties can be propagated may be 

 gathered from the history of one of the most famous new 

 wheats, " Minnesota No. 163," a variety bred by selection. This 

 sprang from a single grain planted in 1892. In 1893 the 

 product consisted of 75 plants; in 1894 a small field plot was 

 grown; in 1898 the crop amounted to some 300 bushels of 

 seed wheat, which was distributed among about 50 farmers 

 throughout the state. It is estimated that in 15 years from 



O > 



the time of planting the single original seed the entire wheat 

 crop of Minnesota, covering some 5,300,000 acres, might have 

 been made to consist of this variety, and that it does actually 

 cover millions of acres, adding about two dollars per acre to 

 the value of the crop. 



It is not yet possible to state how much can be gained in 

 quality and quantity of wheat production by careful culture 

 and breeding. But it is interesting to note that in a good 

 wheat year (1895), when the average crop per acre on the Uni- 

 versity of Minnesota farm was 23 bushels, there were 4 im- 

 proved varieties which yielded over 40 bushels per acre. In 

 1896, when the average crop for the state was 14.2 bushels 

 per acre, out of 32 improved varieties on the University farm 

 there were 24 varieties which yielded 21 bushels per acre or 

 more, 2 of them yielding 33 bushels. That is, three quarters of 

 the varieties yielded at least 1^ times as much as ordinary 



