Annona Species Monograph.pdf - Crops for the Future

Chapter 10. Agronomy
branches. However, cutting and air-layering methods do not produce taproots
and plants are more susceptible to falling over in strong winds, with
subsequent damage and orchard loss. Hence, these vegetative propagation
methods are not recommended where strong winds are a problem.
Cherimoya, soursop and sugar apple can all be successfully inarched with a
high percentage of success (Morton, 1967; Viñas, 1972; Castillo Alcopar,
1997). The inarching method is used to join rootstocks to selected scion
cultivars which are otherwise difficult to root or to graft as detached scions,
as well as to invigorate weak-growing trees by augmenting their root systems
(George and Nissen, 1987). However, this method is much more difficult to
work with and it shows a higher cost/benefit ratio compared with the grafting
and budding methods.
The annonas are easily propagated by budding and grafting, although the
success varies among species. In general, grafted plants grow rapidly but do
not bear fruit any earlier than seedling stocks. Several authors (Moran et al.,
1972; Duarte et al., 1974; George and Nissen, 1987; Torres and Sánchez,
1992; Pinto et al. (2001) and Nakasone and Paull, 1998) have described
splice grafting (Fig. 10-4), also called cleft grafting, as well as shieldbudding
and inverted T budding (Fig. 10-5), as the most successful methods
for vegetative propagation of annonas. Generally, annonas have shown
higher percentage take when propagated by grafting in comparison to other
methods, except for sugar apple, which shows a greater success with budding
(Table 10.2).
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