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Clonal Propagation of the Avocado Through "Franqueamiento"
S. Salazar-Garcia
Subtropical Fruit Researcher, CEICADAR-Colegio
de Postgraduados, Apd, Postal 1-2 Puebla, Pue., Mexico
M.W.
Borys
Research and Visiting Professor from
Introduction
For several years, researchers, nurseries, and producers
from avocado regions all over the world have tried to produce avocado root
cuttings from some avocado varieties. Results have not been very encouraging.
At the present time, some avocado materials chosen
because of their adaptation to drought 'conditions, to floods, to saline soils
and to calcareous soils, as well as for their resistance to Phytophthora
cinnamomi are available in
The best results in avocado clonal propagation have
been obtained with the techniques described by Frolich (1), Frolich and Platt
(2), and Moll and Wood (3); however, we think it possible to develop a more
practical and less expensive method.
In 1979, some research activities were initiated with
the purpose of finding a safer and more efficient method of vegetative propagation
which was expected to work with any genotype of the West Indian, Guatemalan and
Mexican races of Persea
As a result of this, at the present time we have a
procedure being used in research activities at the Fruit Research and Development
Unit of the Puebla Plan, which belongs to the
Training and
Description of Method
The entire procedure is carried out under partially
shaded nursery conditions.
The seed, healthy and previously disinfected, is
planted in a small container (100 mm diameter and 140 mm tall) filled with
sterilized soil (Fig 1). After the new plant has reached a stem diameter
of 5 mm, the variety or selection chosen is grafted as low as possible on the
stem (Fig. 2) When the grafted selection has reached a growth of 150 mm
and has from eight to twelve leaves (Fig. 3), a lengthwise cut is made
from bottom to top with a very sharp blade (Fig. 4); then, a thin piece
of wood (10x10x1 mm) free of resins and previously saturated with Radix 10,000™(which
contains in-dole-3-butyric acid, 10,000 ppm, and naphthalene acetic acid, 300
ppm, in alcoholic solution) is introduced into the cut. Then, with a piece of
thin cotton thread, the small tongue of the stem is pressed against the
introduced piece of wood, fastening it tightly (Fig. 5).
After the piece of wood is placed in the stem, a
piece of black plastic tube is placed in such a way that it embraces the plant
from the soil surface of the container up to 100 mm above the graft point, the leaves
covered by the plastic tube being removed; and the tube is filled with
sterilized soil. (Fig. 6).
It is essential to keep enough humidity in the tube
as well as in the mother plant during all of the procedure.
If the material to be rooted is going to be used as
rootstock, 30 days after placement of the tube the plant may be grafted with
the chosen variety to be later detached and used as a grafted rootstock. The
rooting plant can be detached from the mother plant (Fig. 7) without
risk 70 days after initiation of the rooting process, moving it to a bigger
container (Fig. 8) so it can continue its growth, and it may be grafted
and/or transplanted to the field.
Conclusions
This technique has been proved with such different
varieties as Hass, Wurtz, Fuerte, Duke 6, Duke 7,
Edranol, Waldin, and some other local selections with
excellent results, hi addition to the low investment requirement for equipment.
This method, pioneered in
Literature Cited
FROLICH,
E.F., 1951, Rooting Guatemalan avocado cuttings.
FROLICH, E.F., and R.G. PLATT, 1972. Use of the etiolation technique in
rooting avocado cuttings.
MOLL, J.N., and R. WOOD, 1980. An efficient method for producing rooted avocado
cuttings. Inf. Bull. Citrus and Subtropical Fruit Res. Inst, Nelspruit. I(ll):9-12.
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