RESISTANT VINES; THEIR SELECTION, ADAPTATION, ETC. 45 



Ligatures. In the case of crown or cleft grafts (on vines of more 

 than one year, selected varieties) ligatures are seldom necessary. The 

 only object of binding the graft to the stock is to give solidity, which is 

 furnished by the natural stiffness of a large stock such are usually 

 cleft-grafted. In the case of grafting a vine with a thick trunk, the 

 scion will be held in place naturally. The practice of daubing clay 

 or mud around a graft cannot be too strongly condemned, for it pre- 

 vents respiration which has been shown to be especially necessary for 

 the formation of callus and it furnishes no solidity whatever. 



The smaller the diameter of the stock the more the necessity of liga- 

 tures becomes, for there is not sufficient natural stiffness to maintain 

 the scion in place. 



The use of cotton "grafting twine" (such as is commonly used in 

 nurseries for grafting trees and shrubs above ground) has been 

 abandoned by those who have tried it on grafted vines. The reason is 

 that it has no elasticity, and will not decay in time to permit the free 

 development of the stock, but has to be cut off about June or July. 



The use of patent elastic bands has also been abandoned, because of 

 too great expense; although they are excellent in aiding good joining. 



At one time split corks bound with wire were highly thought of and 

 used to a considerable extent; but owing to the expense of the raw 

 material, as well as the necessity for removing them in July or August, 

 they were abandoned. As in the case of the rubber bands, they accom- 

 plish the object most perfectly, but are too expensive. 



The best and cheapest material now used is raffia, which serves the 

 purpose of holding the two parts of the graft together, and while it is 

 cheap, it seldom requires cutting off, as in ordinary moist soils it will 

 rot off. When first used it is very strong, and will stand all the strain 

 necessary to bind the two parts of the graft firmly together. Owing to 

 the rapidity with which it will rot in very moist, warm soils, and the 

 danger of resulting infection of the joint with the micro-organisms of 

 decay, it is frequently dipped in a solution of from 1 to 3 grams of 

 sulphate of copper to the quart of water. While this certainly accom- 

 plishes its object of preventing infection, it very materially retards the 

 process of callusing. This is obviated, in part, by washing the dipped 

 or soaked raffia in running water, which removes the copper sulphate 

 or bluestone. When " bluestoned " raffia is used, some nurseries use 

 tin or lead strips, around which they tie the ligature of raffia. This is 

 too expensive an operation, however, for very general use, aside from 

 the bad effects of the tin or lead salts that form and hinder the forma- 

 tion of callus. 



Almost every grafter has his own favorite method of tying the knot. 

 This is immaterial, so long as the raffia is not too loosely or closely 

 wound on so as not to afford support or to touch and suffocate. Too 

 close winding prevents free access of air, which has been shown to be 

 necessary for the proper formation of callus. 



We give an illustration of how raffia is usually tied, in Fig. 8 and 

 Fig. 9. 



Time for Grafting. Grafting can be done at almost any time between 

 February and May, according to the season. Some prefer late, while 

 others hold to early grafting. I think that the most experienced and 

 successful grafters prefer the earlier method. The danger from late 



