100 LUTHER BURBANK 



This is of great importance. A great difficulty 

 of the French prune is that its root system is ordi- 

 narily inadequate. It is usually necessary to 

 graft this prune on other roots. Peach stock is 

 sometimes used to advantage both for this and 

 for other varieties of plum. But there are some 

 plums that do not graft kindly on the peach, and 

 it is necessary in such cases to make a double 

 graft, using first a cion of some plum that grafts 

 well on the peach, and then grafting on this the 

 cion of the desired variety. 



This is obviously a rather tedious procedure. 

 Fortunately it has been discovered that the 

 myrobalan plum furnishes good roots on which 

 almost all plums may be grafted, and this stock 

 is becoming very popular. The roots of the 

 apricot are also sometimes used successfully. On 

 deep, dry soil, almond stock often gives the best 

 results with certain varieties. 



But, of course, there will be great advantage 

 if the plum can be made to grow a good set of 

 roots of its own. It should be recalled that an 

 abundance of roots is always closely correlated 

 with abundance of foliage. One may tell at once 

 in the orchard whether a tree has a good system 

 of roots by observation of the foliage. And the 

 close dependence of the roots on the foliage is a 

 matter of common observation. 



