PROPAGATION 



409 



In order to determine the advantages of each system of root- 

 grafting, experiments were carried out by many state experiment 

 stations. These showed that in their earl)- life whole-root trees do 

 better than piece-root trees, but that later there is little difference. 



Both whole-root and piece-root grafted trees are usually cut down 

 to the ground at the end of the first year, and start out the follow- 

 ing spring on equal terms as regards the size of the top. The 

 piece-root graft has made many new roots during the first year, 

 and a difference in growth between the two during the second 



Fig. 179. Whip-grafting 



year is seldom noticeable. The disparity between the two grows 

 constantly less as the trees get older. After three or four years 

 one can rarely detect the difference between them in vigor or size. 



The length of the scion used in root-grafting is thought to make 

 some difference ; however, experiments carried on at the Kansas 

 Station have clearly shown that for practical purposes the length 

 of the scion is of minor importance, but that a length of from 

 6 to 9 inches is preferable. 



Comparison of budding and root-grafting. Practice and experi- 

 ments have fully demonstrated that, so far as the method of 

 propagation is concerned, there is absolutely no difference in the 



