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Root development of P. patulaTerblanche, A. L.( Andries Louis) 12 1900 (has links)
Thesis (MSc.)--Stellenbosch University, 2000. / ENGLISH ABSTRACT: Pinus patula is one of the most important softwood species planted in South Africa
for fibre and timber production and also the main species to be planted in the North
Eastern Cape managed by Mondi Forests. Pinus patula is an exotic species to South
Africa and therefore only commercially exists in man made plantations. Transplants
are being grown in containerised nurseries and flowing from this regime are root
alterations with potential root deformity risks. Current difficulties include poor root
development and instability. The so-called old land syndrome also occurs in old
agricultural soils.
In this study my objective was to investigate the extent of this problem and whether
the problem could be solved by better silvicultural practises. Literature indicated that
bad root development occurs within the period in which transplants are kept in the
nursery. Old land soils have numerous possible variables that could be investigated
and tested. Trials were conducted where different dimensions of transplants, cuttings
and seed were planted under different soil, climate and chemical conditions. Root
development, root weight, root growth potential, shoot growth and survival were
measured in order to establish the ideal containerised seedling dimension for optimum
survival and growth. Ideal growth conditions for optimal transplant and later tree
development in old land soils were also determined.
It was evident that smaller seedlings had better chances of survival and growth. The
effects of container volume and dimension on root development were unfortunately
not tested. My results indicated it a very important factor in root development.
Taproots should not be pruned and the laterals should not start to grow in a horizontal
circular direction, as it will cause an altered root development.
Old lands do not have a single individual factor causing bad survival and growth but
rather a combination of factors. Weed competition weakens the transplants and other
detrimental factors such as pathogens, soil structure deterioration, sub standard
transplants, toxins and soil nematodes aggravate matters. / AFRIKAANSE OPSOMMING: Pinus patula is van die mees belangrike sagtehout spesies tans aangeplant in Suid
Afrika vir vesel en saaghout doeleindes. Genoemde spesie is die hoofspesie geplant
in die studie area naamlik die Noord Oos Kaap bestuur deur Mondi forests. Pinus
patula is ‘n uitheemse spesie en kom kommersieel slegs in plantasievorm voor.
Saailinge word in houer kwekerye gekweek en wortel misvorming kan hieruit
voortvloei. Swak wortel ontwikkeling en onstabiliteit is twee van die hoofprobleme
wat met laasgenoemde ondervind kan word. Die sogenaamde oulandsindroom word
in ‘n erge graad in die studie area ondervind
My studie poog om die omvang van genoemde probleme te ondersoek en of die
probleme opgelos kan word deur verbeterde boskultuurpraktyke al dan nie. Literatuur
dui daarop dat die wortelmisvormingsprobleem hoofsaaklik spruit uit die tydperk
waar die saailing in die kwekery deurbring. Die oorsaak van mortaliteit in oulande is
ook ondersoek.
Eksperimente is uitgele waar verskillende dimensies van saailinge, steggies en saad
geplant en getoets is in verskillende grond, en klimaats toestande. Wortel
ontwikkeling, wortel gewig, wortel groeipotensiaal, lootgroei en oorlewing is gemeet
ten einde die ideale saailing dimensie en groeitoestande vir optimum oorlewing en
groei vas te stel.
Saailinge met ‘n kleiner dimensie het ‘n groter kans tot normale oorlewing en groei.
Houerdimensie en volume is nie in hierdie studie getoets nie. Hierdie studie dui
daarop dat houerdimensie en volume ‘n belangrike faktor is in die ontwikkeling van
wortels. Die studie dui ook daarop dat dit belangrik is om nie in ‘n praktyk te verval
waar die penwortel gesnoei word en laterale wortels horisontaal sirkelvormig begin
groei nie. Genoemde sal wortel vervorming tot gevolg he.
Geen enkel faktor kon vir die swak groei en hoe mortaliteit in oulande
verantwoordelik gehou word nie maar wel ‘n kombinasie van kompeteerders.
Onkruid kompetisie het wel die saailinge onderdruk en gevoelig gemaak vir ander
ouland beperkings soos patogene, grondstruktuurverval, lae standaard saailinge,
toksiene en grondnematode.
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The development of roots and root systems in white spruce (Picea Glauca [Moench] Voss) seedlings and the influence of cultural treatments on root morphology, anatomy, and the capacity to conduct waterKrasowski, Marek J. 02 November 2017 (has links)
Root development in Picea glauca seedlings was studied anatomically during the first year after
germination. The cyclic pattern of elongation of individual roots was established about three
months after germination. With progressing development, root hairs gradually diminished and
colonization of roots by mycorrhizal fungi increased. The development of primary tissues in
long roots, relative to the distance from the root tip, appeared to be related to their rate of root
elongation. In these roots, the development of Casparian bands in the endodermis often occurred
several millimeters away from the root tip. In elongating short roots, endodermal cells attained
their primary state only 2-4 cells away from the proximal part of the apical meristem. In non-elongating
roots, the secondary-state endodermis was connected to the metacutis just above the
apical meristem. The development of Casparian bands was always prior to the maturation of the
first xylem elements. The endodermis did not develop past the secondary state. Through the
presence of passage cells, it remained functional until its disruption by secondary growth. Low
frequency of plasmodesmata in the endodermis indicated that the plasma membrane - cell wall -
plasma membrane type of transport was the main means of molecule exchange between the
cortex and the stele in white spruce roots. Undifferentiated tissues of the root near the apical
meristem were almost impermeable to fluorescent dye tracers Sulforhodamine G and fluorescein
diacetate. The metacutis and the endodermis at the primary and secondary state were
impermeable to the apoplastic tracer Sulforhodamine G.
Roots and root systems were structurally and physiologically affected by cultural treatments such
as pruning and fertilizer application. Roots of seedlings grown at low nitrogen (N) supply were
thin and their tracheids were narrow. Excess N did not significantly increase root diameter and
tracheid dimensions, compared to the optimum supply. Dimensions of bordered pits were not
significantly affected by the N level. The secondary development in roots advanced basipetally
but exceptions were found indicating that cambial growth of roots could vary along the root
regardless of the position relative to the root tip. Seedlings with different root systems modified
by nursery culture exhibited different pattems of root growth after planting. Root elongation and
root surface area increases immediately after planting were greater in container-grown than in
mechanically box-pruned seedlings but this was unrelated to the longer-term performance of
these seedlings. The initially low hydraulic conductance of root systems in box-pruned seedlings increased significantly 6-8 weeks after planting while it remained unchanged or declined in
container-grown seedlings. Root pressure, comparable to that reported for angiosperm seedlings,
was found in white spruce seedlings during the first few weeks after planting. This is contrary to
the general notion that conifers do not develop notable root pressure. The initiation and
elongation of roots in unfertilized organic compartments was poor compared to root growth in
unfertilized mineral compartments, especially in mechanically pruned seedlings whose roots
proliferated in the latter compartments. The growth of roots in the organic substrates was
enhanced by the addition of slow-release fertilizer to that substrate. The growth response of roots
to slow-release fertilizer added to the mineral substrate was restricted to that compartment but
root growth in both soil compartments was affected by the addition of slow-release fertilizer to
the organic substrate. Root development in different types of planting stock was differently
affected by the soil substrate type and the addition of the slow release fertilizer. / Graduate
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Toward a rooting protocol for eucalyptus dunniiRamlal, Nirvana 21 July 2014 (has links)
Eucalyptus dunnii exhibits fast growth, low lignin and high cellulose contents, traits
that are highly desirable for pulp production and are therefore favoured by the paper
industry. In this study, E. dunnii roots were produced by the various methods
practiced by commercial forestry viz. macrocuttings, microcuttings and seedlings.
Roots produced were compared and characterized in order to understand the
distinctions between Eucalyptus roots produced by these methods.
Seedlings and clonal mini-cuttings were sourced from the Trahar Technology Centre,
Mondi (South Africa). Plant shoots were established in culture and multiplied before
the induction of roots in vitro. An optimal growth medium was determined for E.
dunnii multiplication, which was 4.42g.l-1 MS (with vitamins), 25g.l-1 sucrose, 0.2g.l-1
benzyl aminopurine, 0.01g.l-1 naphthaleneacetic acid, 0.1g.l-1 biotin, 0.1g.l-1 calcium
pantothenate, and 3g.l-1 gelrite (pH of 5.6-5.8). Due to the high (68%) levels of
vitrification, tests were conducted to reduce or reverse this phenomenon with no
success. Only healthy material was selected for rooting experiments.
In vitro rooting was tested on medium containing 1.105 g.l-1 MS (with vitamins), 15
g.l-1 sucrose, 0.1 g.l-1 biotin, 0.1 g.l-1 calcium pantothenate, 4 g.l-1 gelrite and pH of
4.5-5.8 and 0.1-1mg.l-1 IBA without success. In vitro rooting (4%) was achieved on
peat:vermiculite (1:2) probably due to less humidity.
Comparison of micropropagated plantlets and seedlings of the same height range
showed that root architecture of main roots, main side roots, number of side root and shoot masses were all statistically similar.
Mini-cuttings underwent treatments before placement into seedling tray inserts
containing coir:perlite (1:2). With the first treatment, the lower excised end of the
shoot was dipped in 20mg.l-1 IBA, for 48 hours while being incubated in a dark and
humid environment; the cutting was then placed into the insert. With the second
treatment, mini-cuttings were placed directly into the prepared inserts for four weeks.
Thereafter, the shoots were carefully removed and underwent the same process as
with treatment one. The third treatment involved dipping mini-cuttings in Seradix 1 0.1% IBA) and placement into the prepared inserts. Treatment 4 involved three pulse
treatments which were tested by placing mini-cuttings into various concentrations of
IBA (20mg.l-1, 200mg.l-1, 2000mg.l-1) in solution for 150 seconds before placement
into the insert. Mini-cuttings devoid of any treatment had approximately the same
percentage success (26%) as those treated with Seradix 1 (25%). Mini-cuttings that
underwent the 200mg.l-1pulse treatments showed the greatest percentage success
(30%).
Mini-cuttings treated with Seradix 1 and seedlings of various sizes (7.5-70cm) were
obtained from the Trahar Technology Centre and the root architecture was analyzed
and quantified. Mini-cutting derived plantlets and seedlings of the same size had
approximately the same shoot:root ratio. Mini-cutting plantlets had a shoot:root ratio
of 2.2:1 and seedlings, 2.8:1 in the 5-7cm height range. In the 7.1-9cm height range,
cutting plantlets had a shoot:root ratio of 2.5:1; and seedlings, 2.4:1. The number of
lateral roots of both seedlings and mini-cutting derived plantlets in each height range
was found to be statistically similar. In the comparison of seedlings of the same height
range as the mini-cutting plantlets sampled, it was observed that the root architecture
differed in root length and structure.
With the comparison of shoot and root growth of different heights (20 to 70cm,
increasing in increments of 10cm) of E. dunnii seedlings, the length of the main roots of seedlings within all height ranges were found to be similar. The same trend was
noted in lateral-root lengths and numbers. While some shoot dry masses were not
significantly different from others. Shoot dry mass of seedlings gradually increased in
accordance with an increase in the height of shoots. With every 10cm increase in
shoot height, shoot mass would increase by approximately 50%.
Although in vitro plantlets, mini-cutting plantlets and seedlings of the same height
range seemed similar in shoot:root ratios and root lengths, no direct comparisons
could be drawn from the study due to the varying growth conditions of the samples
before analysis, as well as restrictions on root growth by containers. To fully
understand root architecture and growth patterns, it is suggested that more field work
is required to obtain an accurate representation at different stages of growth.
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The effects of fungicidal treatments on the rooting of winter cuttings of some woody plants.Procopio, Paul Nicholas 01 January 1954 (has links) (PDF)
No description available.
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Potassium competition in grass-legume associations as a function of root cation exchange capacity.Gray, Bryce Carroll 01 January 1952 (has links) (PDF)
No description available.
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An investigation into the relation of soil compaction and soil fertility as affecting root development in soils.Pearson, Philip R. 01 January 1956 (has links) (PDF)
No description available.
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Cation absorption by excised Barley roots in relation to root cation exchange capacity.Ando, Tadao 01 January 1967 (has links) (PDF)
No description available.
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Investigations into the involvement of calcium and calmodulin in the mediation of maize root growth /Kuzmanoff, Konrad Marc January 1983 (has links)
No description available.
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The relation of functional xylem to absorption and translocation of P³² in Zea mays, L. /Nwoke, Festus Ifeanyichuku Onwubiko January 1967 (has links)
No description available.
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The effects of etiolation and ringing on rooting of myrobalan plum (Prunus cerasifera) cuttings.Yousif, Yousif Hanna January 1972 (has links)
No description available.
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