92 



INTRODUCTION TO BOTANY 



living plant so that the cambium layer of each will be in con 

 tact with that of the other (fig. 75). The plant into which 

 the stem is inserted is called the stock, and the portion of 

 shoot which is set into the stock is called the scion, or graft. 

 There are many kinds of woody plants which may readily be 

 grafted, but the process is of practical im- 

 portance mainly for the grower of apples 

 and pears. Various plans are adopted in 

 different fruit-growing regions. One of the 

 commonest methods for the propagation of 

 apples is root grafting. Seedling trees a year 

 old are dug in the autumn and the roots 

 grafted with one-year-old scions of desired 

 varieties of apple trees, each cut to the 

 length of about six inches. The grafted 

 roots, wound about the joined surfaces with 

 waxed cord, are packed in sand in a cool 

 and not too dry cellar and left until spring. 

 By that time the cambium layers of root 

 and scion have united and the roots are 

 ready to plant. Tongue grafting is practiced 

 in the spring either with young seedlings 

 or with twigs of larger trees (fig. 75). Top 

 grafting consists in cutting off limbs one or 

 two inches in diameter, splitting for a short 

 distance the portion remaining attached to 

 the tree, and inserting at each part of the 

 split, where it crosses the cut surface, a 

 small scion, and then completely covering 

 all exposed parts with grafting wax. Root grafting has the 

 advantage of resulting in a tree with trunk and branches 

 wholly of the desired variety of apple. Tongue grafting of 

 small branches does not interrupt the growth of the tree and 

 is done with very little trouble. Top grafting is mainly 

 resorted to in order to renew old trees that are not bearing 

 the desired variety of apple. 



FIG. 75. Grafting 



At the left, scion and 

 stock are shown ready 

 to be united; at the 

 right, they are joined 

 and ready to be cov- 

 ered with grafting 

 wax. After Percival 



