Thesis (MScAgric)--Stellenbosch University, 1994. / Some digitised pages may appear illegible due to the condition of the Microfiche / ENGLISH ABSTRACT: Many Proreaceae species indigenous to South Africa have potential as cutflower
crops. Commercial production of proteas for expurt, mainly to Europe, must
emphasise quality of flowers and time of production. Good export quality flowers have
stems longer than 50cm and unblemished flowers. Cut-flower proteas are in greater
demand and command better prices during the European winter (September to May,
Southern hemisphere), when competition from flowers grown in Europe is less. Both
quality and time of harvest can be manipulated by pruning techniques.
Protea cv. Carnival (a natural hybrid, possibly between P. neriifolia and P.
compacta) produces flowers in late summer, from February through to May. Picking
flowers or pruning shoots of Proteo cv. Carnival entails removing the terminal portion
of shoots with heading cuts to leave on the plant short stumps, known as bearers.
Lateral shoots arising from axillary buds on bearers elongate by successive growth
flushes until flowers are initiated terminally. The characteristics of the shoot determine
whether or not flower initiation will take place, and will affect the quality of the
resulting flower. Plants were pruned to produce bearers of different length and
diameter. The characteristics of shoots arising from different bearers were recordea.
Thick bearers of length 20-25cm produced the most shoots, and the longest shoots.
Plants producing flowers biennially, rather than ann'Jally, produced thicker bearers,
which, in turn, lead to production of better quality shoots arising from the bearers in
the following season.
Changing the time of pruning changed both the flowering cycle and the biomass
allocation of Prorea cv. Carnival. Plants of Profea cv. Carnival were pruned on six
different dates in 1991. Pruning in March, April or May, 1991, resulted in an annual
flowering cycle. Less than 40% of the fresh mass produced in 1993 was reproductive,
of which approximately 5% had stems long enough for export. The 1994 annual
harvest was of s:milar size and quality as the 1993 annual harvest. Pruning in July,
August or September, 1991, resulted in a biennial cycle of flowering. No flowers were
produced in 1992, and a large crop was harvested in 1993. In 1993 lip to 70% of the fresh mass produced was reproductive, of which approximately 80% had stems long
enough for export. Plants were pruned shortly after flowering in 1993, and the
biennial cycle was replaced by an alternate flowering cycle, with a large crop being
followed by a smaller crop. The large harvest in 1993 was significantly earlier than
normal, but the small crop produced in 1994 was later. The harvest in 1994 from
plants with an alternate flowering cycle was similar in size to the 1994 harvest from
plants floweting annually, but flower stems were longer. / AFRIKAANSE OPSOMMING:
Heelwat inheemse Proteaceae spesies besit die vereiste eienskappe om as
snyblomr.-le verhanctci te wod. Indien proteas kommersieel verbou sou word vir
uitvoer moet die klem val op gehalte van blomme en die tyd van produksie. Goeie
gehalte uitvoer blomme moet steellengte van langer as 50cm en perfek gevormde
blomme besit. Daar is 'n groter aanvraag na kommersieel verboude proteas gedurende
die Europese winter (September tot Mei, suidelike halfrond) en beter pryse word
derhalwe ook dan verkry. Beide gehalte en die oes periode kan gemanipuleer word
deur snoeitegnieke.
Wanneer blomme gepluk word of lote gesnoei word van Profea cv. Carnival
(waarskynlik 'n kruising tussen P. compacta x P. neriifolia) word die terminale
gedeelte van die loot teruggesny. Die oorblywende gedeelte bestaan uit kort stompe
wat bekend staan as draers. Laterale lote afkomstig van okselknoppe op draers verleng
totdat 'n blom terminaal ontwikkel. Die eienskappe van die loot bepaal of 'n blom
inisieer sal word of nie, en sal ook die gehalte van die gevormde blom beinvloed.
Protea plante was gesnoei om draers van verkillende lengtes en deursnee te
produseer. Die eienkappe van lote afkomstig van die verskillende tipe draers was
gemeet. Dik ..draers van lengte 20-25cm het die meeste asook die langste lote
geproduseer. Plante wat twee-jaarliks, in teenstelling met jaarliks, geblom het, het
dikker draers geproduseer en ook gelei tot produksie van beter gehalte lote in die
opeenvolgende seisoen.
Die verandering in die tyd van snoei het beide die blom siklus en die biomassa
verspreiding beinvloed. Plante van Protea cv. Carnival was up 6 verskillende datums
in 1991 gesnoei. Snoei in Maart, April of Mei, 1991, het 'n jaarlikse blom siklus
veroorsaak. Minder as 40% van die vars massa geproduseer in 1993 was reproduktief,
waarvan 5% steellengte lank genoeg vir uitvoer gehad hel. Die 1994 jaarlikse oes was
van dieselfde grootte en gehalte as die van 1993. Snoei in Julie, Augustus of
September, 1991, het egter 'n twee-jaarlikse blom siklus veroorsaak. Geen blomme
was in 1992 geproduseer nie, maar die oes in 1993 was heelwat groter as die jaarlikse
oeste. In 1993 was to 70% van die vars massa geproduseer, reproduktief, waarvan
80% steellengte lank genoeg vir uitvoer gehad het. Die twee-jaarlikse blom siklus het
'n vroeer oes in 1993 veroorsaak, maar 'n later oes in 1994. Die twee-jaarlikse oes in
1994 was van dieseifde grootte as die jaarlikse oes in 1994, maar die blomstele was
langer.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/58407 |
| Date | 12 1900 |
| Creators | Gerber, Audrey I. (Audrey Inga) |
| Contributors | Jacobs, G., Theron, K. I., Stellenbosch University. Faculty of AgriSciences. Dept. of Horticulture. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | English |
| Type | Thesis |
| Format | 48 p. |
| Rights | Stellenbosch University |
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