194 



A.GBONOMY 



and inserted into the bark above and below the wound. In 

 this way the sap is carried past the injury until the tree can 

 cover it with bark. In root grafting the cion is joined to a 

 piece of root. This is regarded as one of the best forms of 

 grafting, since the cion may also put out roots and help to 

 nourish the plant ; in fact, this hardly differs from growing 



a plant from a hardwood cut- 

 ting. In all the forms of whip 

 grafting, stock and cion are 

 carefully bound together with 

 waxed cotton twine or graft- 

 ing wax until a perfect union 

 occurs. Root grafts, being un- 

 derground, do not need this 

 protection. 



Although herbaceous plants 

 are rarely grafted, it can be 

 accomplished. Grafts between 

 the tomato and the potato, the 

 morning-glory and the sweet 

 potato, the artichoke and the 

 sunflower, are now and then 

 reported. In grafting herba- 

 ceous plants veneer grafting 

 is the best form to use, but 

 in this case the cut in the 

 stock should be made deeper 

 than for hard-wooded plants. Even fruits have been grafted 

 when half grown. The grafting of soft-wooded plants is most 

 successful when carried oh under glass, where the conditions 

 of temperature and moisture can be controlled. 



Inarching. Inarching is a form of grafting in which cion and 

 stock are united while both are still joined to their own roots. 

 In this, one stem is bent over toward the other, the cambium 



FIG. 143. Tongue grafting 

 Illustration of one of the best methods 



