CHAPTER XVI 



BREEDING AND SELECTION PROPAGATION AND 

 BREEDING 



POTATOES are propagated from seed, cuttings, lay- 

 ers of green shoots, sprouts from the eyes of tubers, 

 or portions of the tubers containing a bud or eye. 

 About the beginning of the eighteenth century Shirreff , 

 of England, wrote that " the potato is to be considered 

 a short-lived plant," and that " the only way to obtain 

 vigorous plants and to insure productive crops is to have 

 frequent recourse to new varieties raised from seed." 

 Dr. Hunter and T. A. Knight held the same views. 

 T. A. Knight stated that late planting tended to re- 

 invigorate a degenerating variety.' The value of rais- 

 ing new varieties from seed is recognized to-day, and 

 for their production some modern breeders sele<5t as 

 parents two varieties, which in most qualities bear close 

 resemblance to each other, avoiding the use of oppo- 

 sites, the claim being that it is easier to fix the type. 

 Others, including Burbank and Garton, make crosses 

 between widely divergent types, although it takes 

 longer to fix the ones they select and there is a lower 

 percentage worth}' of a trial. There is, however, more 

 chance of obtaining something above the average. 

 Wide crosses act upon the characters in the plant in a 

 manner similar to a vigorous push on the pendulum of 

 a clock it goes higher on each side: plants of higher 



Miller's " Gardeners' Dictionary," ed. :8oy, "Potatoes," and Don's 

 "Gardeners' Dictionary," 1831-38, Vol. IV., pp. 400-406. 



171 



