236 



GRAFTING 



cambium layer on the outer side of the scion may be 

 in contact with the cambium layer of the stock. That 

 the cambium surfaces may be brought into direct contact, 

 at least at one point, the scions are generally slanted 

 slightly outward. Two scions are placed in each cleft to 

 insure success, and if each grows, the weaker one is after- 

 wards removed. 



Cleft grafting is extensively used in top-working trees. 

 A most important factor in this process consists in the 



Fig. 129. Cleft grafting: (a) scion; (6) scions inserted in cleft; (c) cleft graft waxed; 

 (d) cross section of stock and scions. 



selection of the branches to form the top. Scions when 

 grafted always grow upward regardless of the former 

 direction of the stock. This tends to produce a narrow, 

 high-topped tree. Great care should be exercised, there- 

 fore, to select branches well away from the trunk and 

 covering all the fruit-bearing surface. In top- working a 

 matured tree, it will be necessary to graft a large number 

 of branches, but only about one third of these should be 

 worked in a single season. It takes from three to five years 



