64 THE CROWN-GALL AND HAIRY-ROOT OF THE APPLE TREE. 
away soon enough to prevent a constriction of the tree at the point 
of wrapping. 
It is suggested where cloth or cheap calico is used for wrapping 
that sections of the proper width be cut from the end of a bolt of 
cloth, using an ordinary lever paper trimmer, such as is found in 
printing shops. This will give narrow strips of cloth which can be 
placed on a reel in front of the wrapper. In nursery practice it has 
been found best and quickest to secure the end of the cloth after 
the graft has been wrapped by tying it with a half hitch instead of 
waxing it down. In no case should the cloth or any other wrapping 
be secured by drawing it under the end of the scion tongue, because 
anything placed at this point will act as a disturbing element and 
tend to increase the formation of callus and to permit the develop- 
ment of crown-gall. 
LATER EXPERIMENTS IN WRAPPING ROOT GRAFTS. 
A number of nurseries tried wrapping with cloth in 1908, and all 
that have reported to this office obtained good results. Some also 
report good results with waxed cloth and waxed paper. 
Some nurserymen use raffia in place of thread for wrapping root 
grafts with good success. The method they use in wrapping is shown 
by Plate VIII, figure 1, 7. In a small experiment in a greenhouse 
in 1906 raffia was found to be equally as good a wrapping as cloth 
when used as shown in Plate VIII, figure 1, H. There are two objec- 
tions to the use of either cloth or rafia. The first is the increased ex- 
pense of wrapping; the second is that neither is applied by the ordinary 
wrapper, who is usually a boy, in aneffective manner. The lower 
end of the scion is often not bound down closely, allowing the for- 
mation of abundant callus and defeating the very purpose for which 
the cloth and raffia are intended. 
As to what constitutes an ideal wrapping for root grafts the writer 
has repeatedly put himself on record in these words: 
An ideal wrapping should hold the root and scion pieces together firmly till the 
root graft has been planted in the nursery row. It should then rot quickly away. 
The superiority of cloth as a wrapping has resulted in the invention 
by two different persons, one in Missouri and one in Alabama, of a 
continuous thread wrapping for grafts, which is applied evenly and 
closely over the surface of the union, just as thread is wound on a 
spool, and which is apparently superior to either cloth or raffa. 
(See Pl. IX, fig. 2, B.) In 1908 a test was made of this continuous 
thread wrapping for root grafts in comparison with the ordinary 
thread wrapping. (See Pl. IX, fig. 2, A.) Five hundred apple grafts 
were prepared in each manner, using scions from the Wealthy apple, a 
variety very susceptible to crown-gall and hairy-root. The grafts 
186 
