Open Access
Subscription Access
Stump sprouts as sources of cutting production for the vegetative propagation of the threatened African wildolive (Olea europaea subsp. cuspidata)
L Negash
Abstract
Stump sprouts in Olea
europaea L. subsp. cuspidata [(Wall. ex DC.) Ciffieri (syn. Oleaafricana Mill.)]
were initiated by pruning back 4-year-old, 6-year-old and 12-year-old trees to
a height of 25cm from the ground. Additionally,
specimens from 4-year-old trees were pruned back to heights of 120cm and 80cm
from
the ground. Leafy cuttings (with total leaf area, cutting length and cutting
basal diameter reduced to 15–29cm, 8–13cm and 2–3mm per individual cutting,
respectively) were harvested from 14-week-old to 15-week-old sprouts. Rooting
competence of sprouts from trees differing in age was compared by treating
basal ends of cuttings with 30µl of indolebutyric acid (IBA) per cutting.
Experiments were conducted in two separate propagators (two replicates), with
60–70 cuttings per replicate. Cuttings derived from 4-year-old and 6-year-old
stocktree sprouts rooted significantly (P < 0.01) better than those from
12-year-old stocktree sprouts. Initial rooting of cuttings derived from
first-round sprouts of 4-year-old trees was relatively faster than in those from
the second-round sprouts, but the difference in the final rooting was not
significant. Branch cuttings derived from intact, 4-year-old trees (average
height = 230cm), and sprouts derived from stems pruned back to 120cm and 80cm,
resulted in percentage rooting of 11, 14 and 20, respectively. In contrast, up
to 90% rooting was obtained for sprouts derived from severely pruned trees
(average stump height = 25cm). Rooting responses of proximal and distal branch
parts derived from 7-month-old to 8-month-old stecklings (plants derived from
rooted cuttings) were different from each other when these were treated with
either 0.2% or 0.4% IBA, with proximal parts rooting better than the distal
ones. Overall rooting capacity of cuttings derived from seedlings and stecklings
of comparable age was the same. The study found that growth of stecklings
derived from IBA-treated cuttings was significantly (P < 0.01) better than
those from the control, but there was no significant difference among plants
derived from the 0.1%, 0.2%, 0.3% or 0.4% IBA-treated cuttings.
South African Journal of Botany
2004, 70(1): 24–30
europaea L. subsp. cuspidata [(Wall. ex DC.) Ciffieri (syn. Oleaafricana Mill.)]
were initiated by pruning back 4-year-old, 6-year-old and 12-year-old trees to
a height of 25cm from the ground. Additionally,
specimens from 4-year-old trees were pruned back to heights of 120cm and 80cm
from
the ground. Leafy cuttings (with total leaf area, cutting length and cutting
basal diameter reduced to 15–29cm, 8–13cm and 2–3mm per individual cutting,
respectively) were harvested from 14-week-old to 15-week-old sprouts. Rooting
competence of sprouts from trees differing in age was compared by treating
basal ends of cuttings with 30µl of indolebutyric acid (IBA) per cutting.
Experiments were conducted in two separate propagators (two replicates), with
60–70 cuttings per replicate. Cuttings derived from 4-year-old and 6-year-old
stocktree sprouts rooted significantly (P < 0.01) better than those from
12-year-old stocktree sprouts. Initial rooting of cuttings derived from
first-round sprouts of 4-year-old trees was relatively faster than in those from
the second-round sprouts, but the difference in the final rooting was not
significant. Branch cuttings derived from intact, 4-year-old trees (average
height = 230cm), and sprouts derived from stems pruned back to 120cm and 80cm,
resulted in percentage rooting of 11, 14 and 20, respectively. In contrast, up
to 90% rooting was obtained for sprouts derived from severely pruned trees
(average stump height = 25cm). Rooting responses of proximal and distal branch
parts derived from 7-month-old to 8-month-old stecklings (plants derived from
rooted cuttings) were different from each other when these were treated with
either 0.2% or 0.4% IBA, with proximal parts rooting better than the distal
ones. Overall rooting capacity of cuttings derived from seedlings and stecklings
of comparable age was the same. The study found that growth of stecklings
derived from IBA-treated cuttings was significantly (P < 0.01) better than
those from the control, but there was no significant difference among plants
derived from the 0.1%, 0.2%, 0.3% or 0.4% IBA-treated cuttings.
South African Journal of Botany
2004, 70(1): 24–30
Full Text:
EMAIL FULL TEXT
DOWNLOAD FULL TEXT
South African Journal of Botany. ISSN: 0254-6299