BULLETIN

OF THE

Agricultural and Mechanical College
of Texas C

(In cooperation with the United States Department of Agriculture.)

APRIL, 1916 EXTENSION SERVICE No. B-21

TOP- WORKING PECAN
TREES  

 

Address
CLARENCE OUSLEY

Director of Extension Service, College Station, Texas

TOP WORKING PE CAN TREES

By E. J. Kyle, Professor of Horticulture, Dean 0f the School of
Agriculture, Agricultural and Mechanical College of Texas.

Top-working pecan trees has passed beyond the experimental
stage. Some of the methods employed during the experimental
period have been found to be impractical and have been dicarded.
Others, while a success as far as getting the buds to live, has been
found impractical from a commercial standpoint. _There is little
doubt that in the future the methods now in use will be improved
and other successful methods brought into general use.

when Pecan Trees Should Be Top-worked.

' Top-working the pecan will be found to be advantageous under
three general conditions:
1. When native seedlings, that are not too large, are not pro-
ducing satisfactory crops of nuts.
2. When plantings of named varieties have not proven a com-
mercial success in certain sections;
3. When a person who understands propagating the pecan
desires to plant seed where the trees are to stand and top-work
the young seedlings.

Effect of Size and Age on Top-Working.

The age of a tree is not so important as the size, except that
age, under normal conditions, is indicative of size. In using large
trees it is necessary to remove limbs over three inches in diameter,
thus producing wounds that are difficult to heal, which often results
in decay and the final death of the trees. Another objection to
top-working large trees is that the shoots coming out through the
rough bark are not strongly attached to the body of the tree and
frequently break off before or just after budding.

Trees from three to twelve inches in diameter give better rc-

sults than larger sizes. With these sizes it is necessary to be very

careful in order to secure a perfectly sound tree after the new
top has_been developed. Mistakes are frequently made in re-
moving the tops from the larger trees, which often result in the
death of trees or the forcing of shoots in positions where they will
not be able to make strong branches.

Removing the Top.

Trees vary so much in the formation of tops that it is difiicult
to lay down an exact rule for cutting back that will apply in every
case. " When the tree is more than three inches in diameter it is a
serious mistake to remove all of the top-at one time, and the old
method of removing the leader close to the main body is rapidly
being discarded, except in the smaller sizes. Better results are

2

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obtained by cutting the tops back to stubs not more than three
inches in diameter. If it is possible to force out one strong shoot
from each of these stubs the wound will heal quickly, leaving a
sound tree. The proper topping of a tree is a matter of judgment
which must be acquired largely through experience.

Taking all factors into consider-
ation, a vigorous, well-rooted one
to three year old sprout or seed-
ling, measuring from one to two
inches in diameter will give bet-
ter results when top-worked than
will any other age or size. The
most perfect work the writer has
ever seen has been on sprouts and
young trees branching from three
to five feet from the ground and
not more than two inches in dia-
meter. Wounds made on trees of
this size will heal readily, giving
a sound tree with a perfect top in
from one to two years from the
time the work is -done. Trees of
this size and age will not come
into bearing as soon as older trees,
but the work is less expensive and
the percentage of first class spec-
imens secured is much greater.

Methods of Budding.

Ring budding iS probably the
first method put into general use
in working over pecans. This
method generally indicates the
taking of a complete ring of
bark with a bud attached and in-
serting it on a stock from which
a similar piece of bark has been
taken. The ring bud produces a
very severe wound and it is often

“ ‘ difiicult to secure a perfect union.
FIG. l. (U. S. Farmers‘ Bulletin No. 700) The successful use of this method
Pecan tree cut back for top working. requires extreme care and atten-

tion to details. Where the ring
bud is to be used the natural top should be partly removed during
the dormant season or just before growth begins in the spring.
As soon as young shoots have made a growth of from six to eight
inches those that are weak or badly placed should be removed and
only two or three buds allowed to develop around each point where
a bud is to be inserted. This thinning out permits the shoots that

3

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are to be budded to make a better growth and to become more
firmly attached to the body of the tree.

Repeated experiments have demonstrated that ring budding
cannot be started in Texas much earlier than July 1st and cannot
be continued after August 15th, except under unusually favorable
climatic conditions. The success of the work depends on close at-
tention to details, mature buds, a full flow of sap, the character
of the stock and climatic conditions. If all these factors are
favorable, as high as 85 or 90 per cent of the buds may grow.

The percentage
will be m u c h
smaller if only
one of these fac-
tors is unfavor-
able, and com-
plete failure may
result when only
- a few of the fac-
tors show a
marked degree of
unfavorableness.

The patch bud

is a modified
form of ring bud-
ding. It extends
from one-fourth
to one-third the
distance around
the stock. This
gives it an ad-
vantage over the
ring bud in that
it does not make
so severe a
wound and, as a
rule, is easier to

method of bud-
ding requires
practically the
same treatment
and conditions as

FIG. 2. (After Edwards) Annular t/tliddirag. a, Bud stick rlng buddlng.‘
from which the bud has been removed; , the bud ready for in- Ch’ b d_ The
sertion in the matrix of the stock; c, the stock ready to receive , ‘p _ u
the budél d, the bud after being placed in position and carefully HppllCatlOn Of the
wrappe ; e, growth taking place. the wrapping having been re- -
moved; growth from the bud supported by being tied to the chlp bud to the
stock (g above the union. Note the scars above the union, ecan was first
where the buds were removed in order to direct the flow of sap p
to the new bud. A cloth patch is preferred to strips‘ of cloth  WOFkQd ’ out SLIC-

shown in (lrawing. C c S Q f u 1 1 y b y
4

handle. This '

b‘.
_ Kw

Charles L. Edwards of Dallas, Texas, and has come into general
use in nearly all sections of the state. The most essential requisite
to success in chip budding is the wrapping. Many failures are re-
corded and much prejudice has been aroused against this method
through the use of improper wrapping material.

The proper time for chip budding is during the dormant season,
just prior to the beginning of growth in the spring. It is necessary
for the bud wood to be thouroughly dormant and best results are
obtained before the sap starts in the stock, although budding may be
done after the tree has started new growth, provided the buds
have been kept dormant. Under normal conditions this method
may be employed successfully in central Texas between February
20 and April 15. Preferably, the bud should be inserted in one-
year-old growth, although two-year-old wood often gives good re-
sults. The bud should be inserted in a smooth place near the base
of the stock and the stock shortened to not more than twenty inches
beyond the bud. Immediately after inserting the bud it should be
carefully wrapped. The wrapping material consists of a strip of
cloth that has been soaked in beeswax and cut into blocks of about
one and one-half inches in length and one inch wide, with a hole
punched in the center large enough to admit the bud. Rafiia or

p stout twine should be wrapped around the cloth above and below the

bud. When growth starts in the spring all native sprouts should
be removed from the branches and trunk of the tree soon after
they appear. This will necessitate going over the tree every few
days for a perod of about six weeks or two months. By that
time all buds that are alive will have thrust out and made sufiicient
growth to check the development of native sprouts. Soon after the
young shoot is forced out, the raffia should be cut or loosened just
below the bud to prevent girdling. When the young shoot is
twelve or fourteen inches in length the rafiia may be removed en-
tirely and the waxed cloth should be examined carefully to pre-
vent girdling.

The young shoot should now be tied to the stub above where the
bud was inserted. This should remain tied a year or two to pre-
vent the shoot being broken off by the wind. See Fig. 2.

Professor J. A. Evans of Polytechnic, Texas, has met with
splendid success by using only wax in this kind of grafting. In-
stead of using waxed cloth and wraping with raffia, or some other
material, Prof. Evans carefully cov rs all cut surfaces with a thick
coating of wax, composed of parts beeswax to’ one of resin.
The wax and resin are melted together and when partly cooled as
much alcohol as they will absorb is added.

Crown budding. This method of budding is now being em-
ployed successfully in working over pecans in Texas. If the seed-
ling tree is not more than one and one-half inches in diameter the
entire top may be removed at the height of from eighteen inches to
three feet above ground and the bud placed at the crown. The

5

7

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bud is the same as the shield bud, except that the lower end is cut
to a blunt point. The bark is slit. on one side of the crown and the

FIG. 3. (After Edwards) a, shows a dormant pe-
can scion from which a bud has been cut; b, front
view of bud with downward sloping cut at lower
end; c, inside view of same bud with thin layei of
wood to protect germ of bud; d. shows a stock with
bed prepared to receive bud.

 

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  flit

4H
H» "til

FIG. 4. (After Edwards) a, gives front view of
bud fitted on stock; b, waxed cloth wrapper with
eyelet in center; c, shows wrapper fitted on and
properly tied.

bud forced in, as is done
when a shield bud is in-
serted. The bud should
then be covered with a
piece of waxed cloth, as
recommended for the chip
bud, and the crown care-
fully wrapped with from
one to six layers of wax-
ed cloth, depending upon
its size. When trees
four or five inches in
diameter are worked over
by the crown method the
young shoots should be
cut back to stubs and the
buds inserted in the
crown of each stub.
When the stub is more
than one inch in diameter
two or more buds should
be used. If the stubs are
three inches in diameter,
four buds should be used,
spaced equal distance
apart. The best time for
crown budding is just at
the beginning of growth
in the spring, or as soon
as the bark begins to
slip readily. Instead of

using buds it is often
found advisable to use
small twigs containing

from one to three buds.
The twig should be cut on
one side and inserted
just under the bark.

Modified shield bud. This
method “of budding is
practically the same as
crown budding, except
that the bud is inserted

at some point on the body '

of the stock. Also, the lower part of the bud is cut to a blunt

point. _
trees begin to grow in the spring.
(i

The best time to use the modified shield bud is just as the

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FlG.6. (After Iidwards) Mod-
ified Shield Budding. a, shows
stock prepared for bud; b, bud in
place with flaps of bark pared
down; c waxed cloth wrapper; cl,
wrapper in place with nipple of
bud projecting through eyelet i11
wrapper; e, wrapper tied on prop-
erly.
longer.

Top-working p e c a 11
trees offers a great op-
portunity to all persons
interested 1n this 1mpor-
tant Southern industry.
The practice of workmg
over pecans to improved
varieties has not become
as general as 1s the case
with apples, pears, Euro-
pean plums, etc., 1n some
of the Northern and
Western states, but with
the improved methods
now employed and with
the constant improvement
in the work there is no
reason why unprofitable
pecan trees should not be
transformed to varieties
of known merit.

The chip, crown and
modified shield bud have
several advantages over
the ring bud.

1. The work is done
in the early spring, when
the weather conditions
are more pleasant for
work than during the
summer.

2. The young buds are
forced out early in spring,
thus giving them a full
season in which to grow.

3. The bud wood be-
ing dormant in early
spring can be kept in good
condition longer and
shipped further than dur-
ing the summer months.

4. The season in
which the work can be

     

I I

FIG. 5. (After Edwards) Modified Shield Bud-
ding. a, shows first cut in taking off a shield bud
from dormant scion; b, a similar bud modified
by trimming at lower end; c, dotted line where
hncl should be severed from scion; d, front view
of modified shield bud: e. inside view of bud
showing thin layer of wood.