VARIETIES 83 



have vigor. If not, it may fail to establish itself dur- 

 ing the early part of its career, being a shy budder ; 

 it may be readily injured by frost, heat or cold, 

 drouth or a wet period, and, having little recuperative 

 power, will give small returns for the labor bestowed 

 upon it. If it survives to tuber- formation time it will 

 probably fail then. Plants or varieties showing lack 

 of vigor must be discarded. Some varieties have short 

 staying power; they appear to be vigorous for one or 

 two years, and then suddenly collapse. Others have 

 great staying power as, Early Rose, which has been 

 prominent for over forty years. 



The statement is sometimes made that modern vari- 

 eties are not so long-lived as their ancestors that they 

 are deficient in staying power. If the statement were 

 true, it might be explained by saying that new vari- 

 eties are produced more frequently, and that on account 

 of their heavier yielding power or better quality they 

 displace the old ones. The fadls seem to show that 

 modern potato breeders have more than maintained 

 vigor and staying power. Hays, of Minnesota, and 

 others, place the life of a good modern variety at about 

 thirty years. This seems to be accepted by many, 

 both here and abroad. Dr. Hunter, of England, in 

 his " Geological Essays," ! writing about one hundred 

 years ago, states ' ' that varieties continue in vigor 

 about fourteen years, after which the produce gradually 

 declines." Shirreff and T. A. Knight held similar 

 views; the latter wrote 2 that "not a single healthy 



1 "Geological Essays," Exp. 14, p. 348. 



2 Hort. Trans., Vol. I., and Miller's " Gardeners' Dictionary," ed. 1807, 

 "Potatoes." 



