176 PLANT-BREEDING 



the Japanese Prunus triflora. The flesh of the Burbank 

 is red, that of the Kelsey being dull pink and green. 

 The special merit of the breeder Ues in the choice of the 

 parents from which to produce his hybrid. The Wick- 

 son plum is, at present, most largely grown in California 

 for sliipping purposes on account of its high durabihty. 

 It has the unique heart shape of the Kelsey, but the flesh 

 of the Burbank, a rich garnet and yellow color, a large size, 

 and a perfect shape. It is ver}' juicy and deUcious, but its 

 firm skin insures good shipping and keeping quahties. Its 

 first sales in Chicago made the record for plum prices in the 

 United States. It is widely distributed over the world, 

 though somewhat less hardy than other varieties. It has the 

 best quahties of both parents and in many respects surpasses 

 both of them. It is one of the best illustrations of what can 

 be obtained in a single crossing by a man who thoroughly 

 knows all the qualities and characters of liis trees and how 

 to combine them, and who is guided by this knowledge in 

 the choice of the parents for his cross. 



It is exceedingly difficult to gain a correct idea of the 

 influence which the introduction of such novelties can have 

 over the horticulture of some definite country or state. The 

 Burbank, Satsuma, Sugar, and Wickson plums are now 

 largely cultivated in California as well as elsewhere. They 

 have partially supplanted old varieties and have, also, been 

 the means of increasing the acreage devoted to plum culture. 

 But it is manifest that the change of varieties requires the 

 regrafting of the orchards and cannot be performed at once. 

 It often requires ten years or more to revolutionize an es- 

 tabhshed and profitable industry on any large scale. It 

 takes some years to prove the trustworthiness of the new 

 sorts and to convince the fruit-growers of the desirability 

 of the change. The production of a new variety is one great 

 step, but its introduction and distribution is another equally 



