6 
COLORADO EXPERIMENT STATION 
followed by some growers, but will say that only strong-growing 
young trees under the most favorable conditions are worthy of such 
an attempt at .renewal. 
methods oe graft age 
Various methods of graftage may be employed in changing 
over the top of the old trees. Some method of cion-grafting is gen¬ 
erally used, although it is not uncommon, in stone fruits especially, 
to bud into new growths. Of the.methods of cion-grafting two are 
commonly used in the West; cleft-grafting and kerf-grafting. Those 
who have practiced grafting in the East as well as in the West, claim 
that the wood of Western fruit trees is much more brittle and that 
on account of excessive splitting, cleft-grafting is more difficult in the 
West. This has led to the introduction of a new system which is 
locally known as kerf-grafting. 
Cleft-Grafting. The operation of cleft-grafting is very simple. 
The limb to be grafted is sawed off squarely leaving a smooth solid 
stump. The stub is split down about two inches with a grafting- 
chisel or knife. The chisel is removed and the cleft is wedged open 
with the wedge on the back of the knife or one nrovided for the 
purpose. The cion should be cut to contain three buds and should 
be of strong, well-matured' wood of the previous season’s growth. 
The lower end is then trimmed to a wedge leaving the first bud a 
little below the top of the wedge, and cutting the edge of the wedge 
opposite the bud a little thinner than the other. The cion is then 
driven firmly into place with the lower bud to the outside and a 
little below the top of the cleft, being sure to bring the inner bark 
on the outer edge of the wedge in contact with the inner bark on 
the stub. This is the important step in grafting, as it is between these 
parts that the union takes place. Sometimes the inexperienced grafter 
makes the mistake of setting the cion flush with the outer edge of the 
stock. On large stubs with thick bark it would be almost impossible 
to set a cion more illy matched than in this way. Some advocate set¬ 
ting the cion on a slant, the point of the wedge toward the center 
of the stub. This insures a contact of the cambium layers where 
they cross and is a good suggestion, since a point of contact is suf¬ 
ficient for a good union. With a cion properly set in each edge of 
the cleft—providing the stub is large enough—the wedge is removed. 
This allows the cleft to tighten on the cions, the greater thickness 
of the outer edge of the wedge-shaped portion of the cions insuring 
greater pressure at this point. With the removal of the wedge the 
cleft should hold the cions firmly in place. Wax should now be 
applied to all cut surfaces, even to the tips of the cions. Special 
pains should be taken to see that the stub is well covered between 
the cions and the cleft waxed as far as it extends down on the sides 
of the stub. This prevents drying out and it is quite important that 
it be thoroughly done. 
Kerf-Grafting. This system of grafting differs little from inlay¬ 
ing. The stub is prepared as for cleft-grafting, but instead of split¬ 
ting, saw cuts are made on opposite edges of the stub and trimmed 
