Thesis (MTech (Horticulture))--Cape Technikon, Cape Town, 1999 / Vegetative propagation techniques for rooting of cuttings of indigenous tree species, i.e.
Olea europaea subsp. African, Podocarpus falcatus, Syzigium cordatum and introduced
species, i.e. Acacia mearnsii, A. melanoxylon, Eucalyptus grandis and Melia azedarach
were studied and improved at the Cape Technikon nursery from May 1994 to June 1998.
These tree species are considered problematic since the indigenous species produce
unwanted fruits in urban areas which attract frugivores, while the introduced species are a
threat to indigenous vegetation and natural habitats, though they are of great commercial
value.
The progress in mutation breeding of sexual sterility in most of the problematic species
created a need to propagate them vegetatively. Without cloning of seedless species, their
beauty and economic value to South Africa will be lost, as the indigenous species will be
neglected, while invasive species will continue to threaten the natural habitat of indigenous
species.
Experiments were conducted to test age, type and length of cuttings, environmental factors,
growth season, hormone application, various treatments and rooting media for each of
these species. This study showed that relatively few publications relevant to the vegetative
propagation of indigenous tree species are available. However, some introduced species,
e.g. Eucalyptus grandis, are propagated successfully for commercial forestry purposes.
Ficus sur and Syzicium cordatum showed the highest rooting success, i.e. 85-90%,
followed by Olea europaea subsp. africana (75-80%), and Podocarpus falcatus (60%). The
introduced species showed no rooting success, however, callusing in Eucalyptus grandis
(35-61%), and Melia azedarach (50%), and survival rates in Acacia mearnsii (10%) and A.
melanoxylon (20%) were achieved. Treatments, i.e. etiolation, placing plants under stress,
sealing basal stems of cuttings, and fungicide treatments all showed positive results in
promoting callusing success. The study showed that rooting success in individual species
are directly related to the growth stage of parent plants as well as the season during which
the cuttings were taken.
With progress towards successful vegetative propagation of sterile problem plant species,
propagators and horticulturists can in future apply these improved techniques. These
plants will then continue to supply timber, fire wood and improve aesthetics in the South
African urban environment.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:cput/oai:localhost:20.500.11838/846 |
| Date | January 1999 |
| Creators | Laubscher, Charles Petrus |
| Contributors | De Lange, H., Dr, Joubert, C., Ms |
| Publisher | Cape Technikon |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Rights | http://creativecommons.org/licenses/by-nc-sa/3.0/za/ |
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