Annona Species Monograph.pdf - Crops for the Future

Chapter 10. Agronomy
adult trees rooted, but some leafy terminals taken from one year old plants
did, with as much as 25% and 20% rooting with 5000 ppm NAA treatment in
December and January, respectively (Duarte et al., 1974). George and Nissen
(1987) commented that etiolation of propagation materials has given good
results with a high percentage of take in a preliminary study of cherimoya
propagation by cuttings. They said that the extra costs involved in producing
plants by this method may be compensated for by the higher yields and
disease resistance of clonal trees. However, no commercially viable method
for vegetative propagation by cuttings exists to date in cherimoya.
Tip cutting propagation has been described for atemoya (Annona cherimola x
A. squamosa hybrid), with greater success when leaves are attached, versus
without leaves (George and Nissen, 1987; Hartmann et al., 1990). Atemoya
tip cuttings were propagated in mist beds containing a sterilized 50:50
sand:perlite mix and bottom heat with temperatures between 25 and 28°C
(George and Nissen, 1980). An important environmental factor influencing
tip-cutting success is humidity, since desiccation of cuttings prior to
placement in mist beds is a common cause of failure.
In Florida, mature and healthy stem cuttings of sugar apple taken during the
dormant period were propagated successfully by Noonan (1953). He used
shoots between 0.5 and 1.0 cm in diameter and cut into 13-15 cm lengths,
then set them in sand to a depth of 4/5 of their length with one bud exposed
above the surface. The cuttings produced roots 25-30 days after planting.
Bourke (1976) evaluated propagation of sugar apple by root cuttings and
obtained success percentages of less than 5%.
Layering is a type of vegetative propagation by which adventitious roots are
produced on a stem while it is still attached to the parent plant (Hartmann et
al., 1990). A modified layering technique was used by George and Nissen
(1986) with 100% take. They used one year-old cherimoya seedlings and cut
them back severely in mid-summer to produce 3-5 juvenile shoots. When the
new shoots were approximately 15 cm long, metal growth constrictor rings
were placed over each shoot, then a polyethylene sleeve was placed over
each shoot and filled with a mixture of 50% sand and 50% sawdust, leaving
only the growing points exposed. Excellent root systems were produced 4-5
months later. Marcottage (air-layering) of limbs 1.0-1.5 cm diameter on
mature trees of cherimoya cultivar ‘Deliciosa’, however, was unsuccessful,
with less than 5% of marcots rooting (George and Nissen, 1987).
Orchards established with cuttings are more uniform and less expensive to
establish than grafted trees, when cutting materials are taken from pruned
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