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Supporting biodiversity in European vineyards: Possibilities for winegrowers and economic implicationsSchütte, Rebekka 28 June 2019 (has links)
No description available.
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Stikstofomsettinge in gronde met spesiale verwysing na lupine as bron van stikstof vir boorde en wingerdeFourie, S. 12 1900 (has links)
Thesis (MSc)--Stellenbosch University, 1955. / ENGLISH ABSTRACT: no abstract available / AFRIKAANSE OPSOMMING: geen opsomming
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Psychrotolerant mucoralean fungi present in pristine mountain fynbos soil and vineyard soil from the Stellenbosch regionSamson, Heidi E. (Heidi Estrelita) 03 1900 (has links)
Thesis (MSc)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: Mucoralean fungi are mostly saprotrophs that are frequently encountered in soil
habitats. Using an isolation temperature of circa 25°C, other workers obtained
these fungi from a wide diversity of geographical areas in southern Africa.
However, it is known that psychrotolerant mucoralean fungi, able to grow at
25°C as well as at 5°C, occur in pristine Alti Mountain Grassland. Nothing is
known about the diversity of these psychrotolerant soil fungi in other vegetation
types of South Africa.
Consequently, in this study, the psychrotolerant fungal taxa and numbers in soil
from a vineyard and from pristine Mountain Fynbos were determined using an
incubation temperature of 4°C and a complex isolation medium. The latter
contained agar, malt extract, peptone, yeast extract, penicillin and streptomycin
sulphate. Soil samples were analysed in late summer, autumn and mid-winter.
It was found that, for the samples taken in late summer and autumn, the
diversity of mucoralean species in the soil differed between fynbos and
vineyard. In winter however, no significant difference was detected between the
Shannon's diversity indices of mucoralean species in the soil samples taken
from the two habitats. It was found that in both soil types, the percentage
mucoralean fungi on the plates increased from summer to winter. In addition,
the numbers of detectable Morlierella subgenus Morlierella on the plates were
higher in winter than in late summer. The diversity of mucoralean species
obtained during winter in fynbos and vineyard soil was significantly less than the
diversity of these species in Alti Mountain Grassland soil.
To determine if the Morlierella subgenus Morlierella isolates from the fynbos
and vineyard soil, and those obtained from Alti Mountain Grassland, differ in the
ability to grow at low temperatures, the radial growth rate on malt extract agar at
4°C and BOC was determined for each isolate. The results indicate that not only
did seasonal changes occur in the taxa within Morlierella subgenus Morlierella,
but that the isolates dominating the soil in different seasons also differed in the
ability to grow at low temperatures. The percentage of isolates that had
reached greater colony diameters after B days of incubation at 4°C, was higher for the isolates obtained in the cold wet month of July than for those obtained in
the warmer dryer month of February. Similar results were obtained with the
radial growth experiments conducted at BOC. The Morlierella subgenus
Morlierella isolates obtained in winter from fynbos and vineyard soil showed
less variation in low temperature growth rate than the isolates of this taxon
obtained in winter from Alti Mountain Grassland soil during a previous study.
This variation corresponds to the greater number (20) of Morlierella subgenus
Morlierella species found in the grassland soil. Altogether only seven species
of this subgenus was detected during the present study in the fynbos and
vineyard soil samples. It was speculated that this difference in diversity
between the fynbos and vineyard isolates, and the grassland isolates obtained
in a previous study, might have been as a result of differences in the habitat or
the enumeration methods used.
The phylogenetic relationship between different psychrotolerant isolates of
Morlierella subgenus Morlierella originating from the soil of the fynbos, vineyard
and Alti Mountain Grassland, was subsequently determine through comparison
of ITS regions, within ribosomal RNA repeats. Consequently, 45
psychrotolerant Morlierella subgenus Morlierella isolates originating from the
three soil habitats was compared on the basis ITS 1 nucleotide sequence
composition and radial growth rate at 4°C. Phylogenetic analyses showed that
the isolates could be grouped into two clusters correlating with the ability to
grow at low temperatures. Each cluster was further subdivided into two
subgroups. It was found that except for one subgroup and the reference strain
occurring in another subgroup, all the subgroups contain isolates originating
from a single soil habitat. Therefore, the ITS 1 sequence of these fungi seems
to indicate the original habitat and ability to grow at low temperatures. This
correlation of the ITS sequence with the ecological habitat of a fungus has also
been observed by other workers for other fungal groups. / AFRIKAANSE OPSOMMING: Mucoraliese fungi is meestal saprotrofe wat dikwels in grondhabitatte aangetref
word. Deur gebruik te maak van 'n isolasietemperatuur van circa 25°C, het
ander werkers dié fungi van 'n wye verskeidenheid geografiese gebiede in
suidelike Afrika verkry. Dit is egter bekend dat die psigrotolerante mucoraliese
fungi, wat in staat is om by 2SoC en ook by SaC te groei, in ongeskonde Alti
Berg-Grasland voorkom. Niks is egter bekend oor die diversiteit van dié
psigrotolerante grondfungi in ander veldtipes van suidelike Afrika nie.
Die psigrotolerante fungustaksa en -getalle in grond van 'n wingerd en van
ongeskonde Berg Fynbos is gevolglik in dié studie bepaal deur gebruik te maak
van 'n inkubasietemperatuur van 4"C en 'n komplekse isolasiemedium.
Laasgenoemde het agar, moutekstrak, peptoon, gisekstrak, penisillien en
streptomisiensulfaat bevat. Grondmonsters is in die laatsomer, herfs en
midwinter geanaliseer. Daar is 'n verskil gevind tussen die diversiteit van die
mucoraliese spesies in die grond van fynbos en dié van wingerd in die monsters
wat in die laatsomer en midwinter geneem is. In die winter is daar egter geen
beduidende verskil gevind tussen die Shannon diversiteitsindekse van
mucoraliese spesies in die grondmonsters wat uit die twee habitatte getrek is
nie. In albei grondtipes is daar gevind dat die persentasie mucoraliese fungi op
die plate toegeneem het van somer tot winter. Daarby was die aantal
waarneembare Morlierella subgenus Morlierella op die plate meer in die winter
as in die laatsomer. Die diversiteit van mucoraliese spesies wat in die winter uit
fynbos- en wingerdgrond verkry is, was beduidend minder as die diversiteit van
dié spesies in Alti Berg-Grasland grond.
Om te bepaal of die Morlierella subgenus Morlierella isolate van die fynbos- en
wingerdgrond en dié van Alti Berg-Grasland van mekaar verskil ten opsigte van
hul vermoë om by lae temperature te groei, is die radiale groeitempo op
moutekstrak by 4"C en aoc vir elke isolaat bepaal. Die resultate dui aan dat
daar nie alleen seisoenale veranderinge in die taksa binne Morlierella subgenus
Morlierella voorkom nie, maar dat die isolate wat tydens verskillende seisoene
uit die grond verkry is, ook ten opsigte van hul groeivermoë by lae temperature van mekaar verskil. Die persentasie isolate wat groter kolonie diameters bereik
het ná B dae inkubasie by 4°C, was hoër vir die isolate van die koue, nat
Juliemaand as vir dié wat in die warmer en droër Februariemaand verkry is.
Soortgelyke resultate is verkry met radiale groei-eksperimente wat by BOC
gedoen is. Die MortierelIa subgenus MortierelIa isolate wat in die winter uit
fynbos- en wingerdgrond verkry is, het In kleiner variasie in hul groeitempo by
lae temperature getoon as die isolate in dié takson wat tydens 'n vorige studie
in die winter uit Alti Berg-Grasland grond verkry is. Dié variasie stem ooreen
met die groter aantal (20) MortierelIa subgenus MortierelIa spesies wat in die
graslandgrond gevind is. Slegs sewe spesies van dié subgenus is gedurende
die huidige studie in die fynbos- en wingerdgrondmonsters waargeneem. Daar
is gespekuleer dat dié verskil in diversiteit tussen die fynbos- en wingerdisolate
en die graslandisolate van die vorige studie die gevolg mag wees van verskille
tussen die habitat of die enumerasiemetodes wat gebruik is.
Die filogenetiese verwantskap tussen verskillende psigrotolerante isolate van
MortierelIa subgenus MortierelIa uit die grond van die fynbos, wingerd en Alti
Berg-Grasland, is vervolgens bepaal deur 'n vergelyking van interne
getranskribeerde spasieerder (ITS) areas, binne ribosomale RNS herhalings.
Daar is gevolglik 45 psigrotolerante MortierelIa subgenus MortierelIa isolate uit
die drie grondhabitatte met mekaar vergelyk op grond van die basis ITS 1
nukleotied opeenvolgingsamestelling en radiale groeitempo by 4°C.
Filogenetiese analises het die isolate in twee groepe verdeel op grond van hul
vermoë om by lae temperature te groei. Elke groep is verder in twee subgroepe
verdeel. Daar is gevind dat behalwe vir een subgroep en die verwysingstam
wat in 'n ander subgroep voorgekom het, elkeen van die subgroepe bestaan het
uit isolate wat van 'n enkele grond habitat verkry is. Dit wil dus voorkom of die
ITS 1 opeenvolging van dié fungi 'n aanduiding gee van die oorspronklike
habitat en die vermoë om by lae temperature te groei. Dié korrelasie tussen die
ITS opeenvolging en die ekologiese habitat van 'n fungus is ook deur ander
werkers vir ander fungusgroepe waargeneem.
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Evaluering van grondvoorbereidingspraktyke wat in die wingerdbedryf uitgevoer word in terme van geselekteerde grondfisiese eienskappeKritzinger, Daniel Jacobus 03 1900 (has links)
Thesis (MScAgric)--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: The study was conducted in the Western Cape Province to investigate the effect of soil
preparation on selected soil physical properties. This study was necessitated by the negative
effects that high soil bulk density has on the growth and production of a vine. Soil preparation
in South Africa are applied to remove root limiting layers in the subsoil and to create a larger
soil volume for root growth. The question is whether it is always necessary because of the
destruction of macropore structure and also the high costs that is involved. The study includes
different soil forms, different depths of tillage, different tillage operations and also the change
of soil physical properties with time. Soil physical properties that was investigated include,
bulk density (cloth method), infiltration (mini disk infiltrometer and double ring
infiltrometer), shear strength (pocket vane tester), soil strength (penetrometer) and root
distribution (profile wall method).
The main finding was that the positive effects of soil preparation were still clear after 25
years. The bulk density, shear strength, penetration resistance and infiltration with the double
ring infiltrometer of the deeper soil preparation practices were considerably lower than those
of undisturbed soil. Soil preparation shallower than 60 cm recompacted more than the deeper
tillage treatments. Hydraulic conductivity with the mini disk infiltrometer yielded mixed
results. This was mainly because measurements represented hydraulic conductivity through
the whole profile and therefore can be influenced by many factors. Root distribution has
increased with depth of tillage and the effect was clear at Nietvoorbij in the deeper (> 60 cm)
soil preparation treatments. There were no significant difference between the two soil
preparation methods (delve plough and soilmix) at Kanonkop, although the effect of
secondary compaction by the soilmix was quite clear. Recompaction over a year was clear in
the 2009 and 2010 tillage treatments at Broodkraal. The methods that were used to determine
the soil physical properties have all yield good results. At all the sites the tillage treatments
generally yielded better results than the undisturbed soils. It was also clear that the longer the
time after tillage the smaller become the difference between the tillage treatments and the
undisturbed soils. Recompaction did occur and therefore soil preparation might possibly be
applied again before new vines wants to be planted. / AFRIKAANSE OPSOMMING: Die studie is in die Wes-Kaap Provinsie gedoen om die effek van grondvoorbereiding op
geselekteerde grondfisiese eienskappe te ondersoek. Hierdie studie is genoodsaak deur die
nadelige gevolge wat hoë gronddigthede op die groei en produksie van ’n wingerdstok het.
Grondvoorbereiding in Suid-Afrika word toegepas om beperkende lae in die ondergrond te
verwyder en sodoende ‘n groter grondvolume vir wortelgroei beskikbaar te stel. Die vraag is
egter of dit altyd noodsaaklik is weens die vernietiging van voorkeur vloeikanale en die hoë
kostes wat daarmee gepaard gaan. Die studie sluit verskillende grondvorms, verskillende
dieptes van bewerking en verskillende tipes bewerking in asook hoe die toestande met
verloop van tyd verander. Grondfisiese eienskappe wat ondersoek is, sluit in: bulkdigtheid
(kluitmetode), infiltrasie (“mini disk” - en dubbelring infiltrometer), skuifsterkte (skroefbladmeter),
grondsterkte (penetrometer) en wortelverspreidings (profielwand metode). Die studie
is uitgevoer by drie verskillende proeflokaliteite, nl. Nietvoorbij, Kanonkop en Broodkraal.
Die vernaamste bevindings was dat die grondvoorbereidingsbehandelings se voordelige effek
oor die langtermyn, na 25 jaar, steeds duidelik waarneembaar was. Die bulkdigtheid,
skuifsterkte, penetrasieweerstand en infiltrasie met dubbelring infiltrometer van die dieper
grondbewerkingspraktyke was aansienlik laer as die kontrole behandelings (onversteurde
grond) gewees. Die grondvoorbereidingsaksies vlakker as 60 cm het tot ʼn mate weer
herverdig. Hidrouliese geleiding met minidisk infiltrometer het baie wisselvallige resultate
opgelewer. Dit is hoofsaaklik omdat die meting die geleiding deur die hele profiel
verteenwoordig en daar baie faktore is wat dit kan beïnvloed. Die wortelverspreiding het met
diepte van grondbewerking toegeneem en die langtermyn voordelige effek was duidelik by
Nietvoorbij in die dieper (> 60 cm) grondvoorbereidingsbehandelings sigbaar. Die twee
grondvoorbereidingspraktyke (dolbewerking en “soilmix”) by Kanonkop het nie betekenisvol
van mekaar verskil nie, alhoewel die effek van sekondêre kompaksie soos veroorsaak deur die
“soilmix” implement, duidelik was. Herverdigting oor die tydperk van ’n jaar was duidelik
tussen die 2009- en 2010 bewerking by Broodkraal. Die metingsmetodes waarmee die
grondfisiese eienskappe ondersoek is, het almal goeie resultate gelewer. By al die
proeflokaliteite het die bewerkingsbehandelings oor die algemeen beter resultate as die
kontrole-behandelings (onversteur) gelewer. Hoe langer die tydperk na grondvoorbereiding
hoe kleiner was die verskil tussen die bewerkingsbehandelings en die kontrole. Herverdigting
het wel voorgekom en daarom sal grondvoorbereiding moontlik weer toegepas moet word
wanneer nuwe aanplantings gemaak word.
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The edaphic and climatic effects on production and wine quality of Cabernet Sauvignon in the Lower Olifants River regionBruwer, Rachel Jacoba 03 1900 (has links)
Thesis (MScAgric (Viticulture and Oenology))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: Cabernet Sauvignon is the most planted red cultivar in South Africa and the second
most planted red cultivar in the Olifants River region. The cultivar is prone to vigorous
growth with low yields. Excessive irrigation could accentuate these cultivar
characteristics. Considering the foregoing, the aim of the study was to describe how
Cabernet Sauvignon will react to climate, soil type (texture) and irrigation within the
Lower Olifants River wine region to enable growers to make the right decisions
regarding long term as well as short term cultivation practices. This study is part of a
project carried out by the ARC Infruitec-Nietvoorbij at Stellenbosch to determine the
effects of soil type and atmospheric conditions on yield and wine quality of Cabernet
Sauvignon in different grape growing regions of South Africa. Similar studies are being
carried out in the Orange River, Stellenbosch and Swartland regions of South Africa.
The Lower Olifants River region could be divided into three climatic regions.
Furthermore, two climatic regions is evident regarding the formation of grape wine
colour and aromas. Proximity to the Atlantic Ocean would play an important role in a
cultivar establishment policy.
The variation in stem water potential (ΨS) could be related to soil water status
expressed in terms of matric potential (ΨM). In the case of sandy soils, ΨS decreased
substantially more as the ΨM decreased compared to the sandy loam soils. The reason
could be that the unsaturated hydraulic conductivity in sandy soils decreased more
rapidly as the ΨM decreased compared to the heavier soils. Thus could explain why the
grapevines in the sandy soils experienced more water stress than the ones in the sandy
loam soils at a given ΨM.
Climate had a strong influence on grapevine water status with grapevines nearer to
the ocean experiencing less water stress compared to the ones further inland. This was
especially true for grapevines in the sandy soils.
Vegetative growth and yield of grapevines in the sandy soils were more sensitive to
water deficits compared to the ones in the sandy loam soils. For deficit irrigated
grapevines in the sandy soils, vegetative growth and yield decreased by ca. 30% when
ca. 55% less water was applied from flowering to harvest. Yield reduction were ca. 15%
with no or very little influence on vegetative growth with ca. 80% reduction in water
applied from flowering to harvest for grapevines in the sandy loam soils.
The influence of soil texture on wine quality and style were evident under intensive
irrigation as well as over different climatic regions. Overall sensorial potential wine
quality of grapevines in sandy soils tended to be higher compared to the ones in the
sandy loam soils. Deficit irrigation tended to increase wine colour intensity, irrespective
of soil texture. Furthermore, deficit irrigation in sandy loam soils tended to increase wine
fullness and the berry characteristics of the wine. Berry characteristics of wines from the
sandy soils tended to be higher compared to the ones from the sandy loam soils. Too
severe water deficits in sandy soils could be detrimental to wine quality. Climate tended to have an influence on wine style of grapevines in the sandy soils with wines produced
further away from the ocean tended to have higher berry characteristics.
Irrigation management could be a powerful tool to manipulate the grapevine in
sandy soils. For grapevines the sandy loam soils in addition to regulated deficit
irrigation, additional canopy management practices could be needed to improve wine
quality. / AFRIKAANSE OPSOMMING: Cabernet Sauvignon is die mees aangeplante rooidruif kultivar in die Suid-Afrikaanse
wynbedryf. In die Olifantsriver streek is dit naas Shiraz, die tweede mees aangeplante
rooidruif kultivar. Cabernet Sauvignon is bekend as ‘n groeikragtige skaamdraer. Indien
oorbesproei word, kan hierdie potensiële nadelige eienskappe nog meer na vore tree.
Die doel van die studie is om die invloed van die klimaat, grond en besproeiing op
Cabernet Sauvignon se vegetatiewe groei, produksie en wyngehalte in die Benede
Olifantsrivier streek te bepaal. Hierdie inligting kan produsente help om ingeligte kortsowel
as langtermyn besluite te maak rakende die verbouing van Cabernet Sauvignon.
Hierdie studie vorm deel van ‘n breër studie in die Suid-Afrikaanse wynbedryf, gedryf
deur die Landbou Navorsingsraad (LNR) Infruitec-Nietvoorbij, Stellenbosch om die
invloed van atmosferiese toestande en grond op die produksie en wyngehalte van
Cabernet Sauvignon te bepaal. Soortgelyke projekte word uitgevoer in die Oranjerivier,
Stellenbosch en Swartland wynstreke.
Die Benede Olifantsrivier streek kan verdeel word in drie klimaatstreke op grond
van temperatuurdata. In terme van die ontwikkeling van druifkleur en aromas, kan die
streek verdeel word in twee klimaatstreke. Die afstand vanaf die Atlantiese Oseaan kan
‘n belangrike rol speel in die ontwikkeling van ‘n kultivarriglynplan vir die streek.
Grondwaterstatus, uitgedruk as die matrikspotensiaal (ΨM), kan aanleiding gee tot
variasie in middag blaarwaterpotensiaal (ΨS) lesings. Die ΨS van die sand gronde
verlaag vinniger soos die ΨM verlaag invergelyke met die sandleem gronde. Dit kan
moontlik wees as gevolg van die verskil in die grond onversadigde hidroliese
konduktiwiteit. Sand gronde se hidroliese konduktiwiteit verlaag vinniger soos die ΨM
verlaag, invergelyke met sandleem gronde. Dit verklaar waarom wingerde in sand
gronde by dieselfde ΨM, meer waterspanning ondervind as wingerde in sandleem
gronde.
Klimaat het ‘n invloed op die waterstatus van die wingerdstok. Wingerde nader aan
die see het minder waterspanning ondervind invergelyke met wingerde wat verder in die
binneland geleë is. Dit was veral die geval met wingerde in die sand gronde.
Vegetatiewe groei en produksie van wingerde in die sand gronde is meer sensitief
vir waterspanning as wingerde in die sandleem gronde. Tekortbesproeiing in die sand
gronde het die groei asook produksie met ongeveer 30% verlaag deur ongeveer 55%
minder water toe te dien vanaf blom tot oes. In teenstelling daarmee is die produksie
van wingerde in die sandleem gronde met ongeveer 15% verlaag met geen tot baie min
verlaging in die groeikrag. Ongeveer 80% minder water is toegedien vanaf blom tot oes.
Grondtekstuur kan wyngehalte en -styl beïnvloed ten spyte van intensiewe
besproeiing en klimaatsverskille. Sensoriese potensiële wyngehalte van wingerde in die
sand gronde was beter invergelyke met dié van die sandleem gronde. Die wyne vanaf
die sand gronde het ook geneig om oor meer bessie intensiteit te beskik as wyne vanaf
die sandleem gronde. Tekortbesproeiing neig om die wynkleur intensiteit te verhoog,
ongeag van grondtekstuur. Tekortbesproeiing in die sandleem gronde kan ook die
volheid van die wyne verbeter, asook die bessie intensiteit van die wyn verhoog. Te hoë waterspanning in die sand gronde kan wyngehalte nadelig beïnvloed. Klimaat kan ook
die wynstyl vanaf sand gronde beïnvloed met wyne verder vanaf die see wat oor meer
bessie intensiteit beskik as wyne nader aan die see.
Beheerde tekortbesproeiing kan as ‘n kragtige hulpmiddel gebruik word om
wingerde in die sand gronde te manipuleer. Vir wingerde in die sandleem gronde,
addisioneel tot beheerde tekortbesproeiing en normale loofbestuurspraktyke, kan ekstra
loofbestuurspraktyke bv. die verwydering van sylootlote, dalk nodig wees om
wyngehalte te verbeter.
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Effect of climate and soil water status on Cabernet Sauvignon (Vitis vinifera L.) grapevines in the Swartland region with special reference to sugar loading and anthocyanin biosynthesisMehmel, Tara Olivia, Van Heerden, Tara Olivia 23 November 2010 (has links)
Thesis (MScAgric (Viticulture and Oenology))--University of Stellenbosach, 2010. / ENGLISH ABSTRACT: Cabernet Sauvignon, the most planted red wine cultivar in South Africa, is prone to vigorous
growth with low yields. The aim of the study was to describe how Cabernet Sauvignon
grapevines react to climate and irrigation within the Swartland region. Such knowledge would
assist growers in decisions regarding long term as well as short term cultivation practices. This
study was part of a larger project carried out by the Infruitec-Nietvoorbij institute of the
Agricultural Research Council at Stellenbosch to determine effects of soil type and climate on
yield and wine quality of Cabernet Sauvignon. The larger project was carried out in selected
grape growing regions, i.e. Stellenbosch, Swartland, Lower Olifants River and Lower Orange
River.
Due to the proximity to the Atlantic Ocean, the study area in the Swartland region could
be divided into two climatic regions for viticulture. Grapevines near Philadelphia closer to the
ocean experienced less water constraints compared to those further inland near Wellington.
Variation in stem water potential could also be related to soil water matric potential. Climate
tended to have a more pronounced effect on the grapevine response to water constraints
further inland than closer to the ocean. Vegetative growth, berry size and yield depended on
water constraints experienced by the grapevines. In the warmer climate, severe constraints
reduced yield.
In the warmer climate, grapes started to ripen earlier than those in the cooler climate.
Sugar concentration (mg/mL) was highest where grapevines experienced moderate water
constraints. These seemingly balanced grapevines had the highest sugar accumulation,
probably due to optimum photosynthesis and carbohydrate utilization. Low water constraints
increased vegetative growth which could have been a sink for sugar loading. In addition to
sugar loading, degree Balling (°B) increases could also have been due to a concentration effect
where water constraints reduced berry volume. Therefore, °B is probably not a representative
indicator of grapevine functioning.
Anthocyanin biosynthesis, as quantified on a per berry basis, showed that sugar and
anthocyanin could be co-regulated, with anthocyanin biosynthesis reaching a plateau when the
sugar content per berry reached 200 mg/mL to 220 mg/mL. At véraison, the most intense grape
colour occurred where grapevines experienced moderate water constraints, i.e. single drip line
at Wellington and no irrigation at Philadelphia. However, at harvest grapes from the cooler
climate tended to have more intense colour and higher phenolics, indicating that lower
temperatures favoured anthocyanin biosynthesis. These results supported earlier findings that
grapevine water status influences berry volume and dynamics of berry ripening.
Water constraints tended to increase sensorial wine colour intensity, as well as wine
fullness. Moderate water constraints at both localities resulted in the best sensorial wine quality.
Yet there were indications that too severe water constraints could be detrimental to wine quality. Irrigation can be used to manipulate grapevine growth in warmer climates, but might be less
effective in cooler climates. In warmer climates, moderate water constraints required to achieve
balanced grapevine functioning can be obtained with single drip irrigation, but this might not be
the case in cooler climates. / AFRIKAANSE OPSOMMING: Cabernet Sauvignon, die mees aangeplante rooiwynkultivar in Suid-Afrika, is geneig tot kragtige
groei met lae opbrengste. Die doelwit van hierdie studie was om te beskryf hoe Cabernet
Sauvignon-wingerdstokke reageer op klimaat en besproeiing in die Swartland-streek. Hierdie
kennis sal kwekers help wanneer hulle besluite moet neem oor langtermyn sowel as korttermyn
verbouingspraktyke. Hierdie studie was deel van ‘n groter projek deur die Infruitec-Nietvoorbij
Instituut van die Landbounavorsingsraad op Stellenbosch om die effekte van grondtipe en
klimaat op die opbrengs en wynkwaliteit van Cabernet Sauvignon te bepaal. Die groter projek is
in geselekteerde wingerdverbouingstreke uitgevoer, nl. Stellenbosch, Swartland, Benede
Olifantsrivier en Benede Oranjerivier.
As gevolg van die nabyheid daarvan aan die Atlantiese Oseaan kon die studiegebied in
die Swartland-streek in twee klimaatstreke vir wingerdbou verdeel word. Wingerdstokke by
Philadelphia, wat nader aan die oseaan is, het minder waterstremming ervaar as dié verder
binnelands naby Wellington. Veranderinge in stamwaterpotensiaal hou moontlik ook verband
met die grondwater- matrikspotensiaal. Klimaat het ‘n groter effek op die reaksie van die
wingerdstok op waterstremming verder binnelands as nader aan die oseaan. Vegetatiewe groei,
korrelgrootte en opbrengs was afhanklik van die waterstremminge wat deur die wingerdstokke
ervaar is. In die warmer klimaat het die ernstige stremminge opbrengs verminder.
In die warmer klimaat begin druiwe vroeër ryp word as in die koeler klimaat.
Suikerkonsentrasie (mg/ml) was die hoogste waar wingerde matige waterstremming ervaar het.
Hierdie skynbaar gebalanseerde wingerdstokke het die hoogste suikerakkumulasie vertoon,
moontlik as gevolg van optimum fotosintese en koolhidraatverbruik. Lae waterstremming het
vegetatiewe groei verhoog, wat ook ‘n vraagpunt vir suikerlading kon wees. Benewens
suikerlading kon verhogings in grade Balling (°B) ook moontlik aan ‘n konsentrasie-effek
toegeskryf word in terme waarvan waterstremming die korrelvolume verminder het. °B is dus
moontlik nie ‘n verteenwoordigende indikator van wingerdstokfunksionering nie.
Antosianienbiosintese, soos gekwantifiseer op ‘n per-korrel basis, het getoon dat suiker
en antosianien saam gereguleer kon word, en dat antosianienbiosintese ‘n plato bereik het
wanneer die suikerinhoud per korrel 200 mg/mL tot 220 mg/mL was. By deurslaan het die mees
intense druifkleur voorgekom waar die wingerdstokke matige waterstremming ervaar het, d.w.s.
enkel druplyn op Wellington en geen besproeiing op Philadelphia. Teen oes was die druiwe in
die koeler klimate egter geneig om meer intense kleur en meer fenole te bevat, wat aandui dat
laer temperature antosianienbiosintese bevoordeel. Hierdie resultate ondersteun vroeër
bevindings dat die waterstatus van die wingerdstok ‘n invloed op korrelvolume en die dinamika
van korrelrypwording het.
Waterstremming neig om die sensoriese wynkleurintensiteit te verhoog, asook die
volheid van die wyn. Matige waterstremming op beide liggings het aanleiding gegee tot die beste sensoriese wynkwaliteit. Tog was daar aanduidings dat waterstremming wat te straf was,
nadelig kon wees vir wynkwaliteit. Besproeiing kan gebruik word om wingerdgroei in warmer
klimate te manipuleer, maar is moontlik minder effektief in koeler klimate. In warmer klimate kan
die matige waterstremming wat benodig is vir gebalanseerde wingerdstokfunksionering, verkry
word deur enkel drupbesproeiing, maar dit is moontlik nie die geval in koeler klimate nie.
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Identification of terroirs in the Robertson valley for Chardonnay and Shiraz : a focus on soil and rootsErazo-Lynch, Leonardo 03 1900 (has links)
Thesis (MScAgric (Viticulture and Oenology))--University of Stellenbosch, 2011. / Includes bibliography. / ABSTRACT: The grapevine must constantly find a balance between two continually changing environments,
the rhizosphere (i.e. soil) and the troposphere (i.e. macroclimate). The adaptations are
extremely complex because they encompass complicated and interrelated processes that are
not yet fully understood.
In terms of water-use behaviour, differences between cultivars have been described in the
literature. In this study, the water status and stomatal conductance of four cultivars (Shiraz,
Grenache, Pinot noir and Chardonnay) grafted onto R99 were studied. Diurnal cycles of water
status and stomatal conductance, from 07:00 to 19:00, were followed for a single day at the end
of the 2009 season. The results showed that, at the end of the season, Shiraz was subjected to
water stress conditions, losing leaves and showing symptoms of berry shrivelling. The other
three cultivars had a much better canopy status and no symptoms of berry shrivelling were
observed. Based on the canopy observations and a comparison of the curves of stem water
potential (Ψs) and stomatal conductance (gs), it seems that Pinot noir and Chardonnay are
closer to the water-use behaviour of Grenache noir, which is known as a “pessimistic” cultivar,
than to Shiraz, which is an “optimistic” cultivar.
A study of four plots each of Chardonnay/101.14 Mgt and Shiraz/101.14 Mgt was carried out in
eight commercial vineyards in the Robertson region in order to investigate the relationship
between soil and root morphology, and the influence thereof on canopy development and berry
growth. These plots had different soil types. Important soil properties are reported to limit root
growth, individually or as a combination of restrictions. It was found that the size of the root
system of 101.14 Mgt is defined by soil physical and chemical properties. The roots of 101.14
Mgt under irrigation can grow to a depth of 100 cm or beyond if the soil physical and chemical
properties allow it.
Because the soil properties define the root system and the water storage/drainage, they greatly
influence the plant water status, even under irrigation. In an arid zone like Robertson, irrigation
is an important management tool. The balance between canopy growth before véraison and the
ability of the root-soil system to maintain that canopy size during the ripening process is crucial
in an area with a high evaporative demand. In this regard, not all the soil properties-root system
combinations showed satisfactory performance in maintaining the canopy functioning, which
affected berry sugar loading and berry volume.
In another study that is presented, forty soil profiles were characterised in the Robertson valley.
The root systems were considered as a product of the soil properties, and thus the morphology
of the root systems was used as a starting point to group soils together. The importance of soil
depth has been described well, thus the root systems were first classified according to rooting
depth – into shallow and deep root systems. The deep root systems were then subdivided,
creating two subgroups of high root density and low root density. The two extreme groups (i.e.
shallow roots, and deep roots with high root density) have particularly different soil properties.
The soil characteristics found in these extremes are represented up to certain point by families
of the South African soil taxonomy, mainly due to the restrictive function of the B horizon. This
restrictive function is related to soil properties that are taken into consideration in the South
African soil classification and that are important for grapevine root growth, as well as the
thickness of the described horizons and the physical and chemical differences between the
horizons.
Soil properties have an important influence on root morphology. Due to the fundamental role
played by the root system in the overall plant functioning, soil properties are of critical
importance. In an arid area, the low water pressure in the atmosphere and the high temperature
greatly affect the plant water status. The soil-root system combination plays an important role in
the ability of the root system to supply the plant with water during times of high evaporative
demand. Different cultivars will react differently due to differences in transpiration control. The
maintenance of an adequate water status will have an immense influence on canopy
development and maintenance, and on normal and steady berry ripening. In this study it was
found that not all the soil-root combinations can fulfil this satisfactorily. Thus, the grapevine
balance determined by the combination of the soil-root-canopy complex and the influence of
management techniques is extremely important for the favouring of a good canopy:root system
ratio, a functional canopy throughout the season and a steady berry ripening curve.
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Veřejný život na Královských Vinohradech (1880 - 1922) / Public life on Roayal Vineyards (1880 - 1922)Charamzová, Alena January 2015 (has links)
This diploma thesis focuses on the issue of public life on Royal Vineyards in the period of 1880 - 1922. First of all, particular factors that form the image (character, identity) of Royal Vineyards as czech, healthy, modern and independent city with historical tradition, inhabited mainly by middle class population, are analysed. Further more the thesis is discussing czech public life on Vineyards. By the term public life is here meant an analysis of the formation and appearance of vineyard public spaces and cultural facilities and their importance for residents of Vineyards. Thesis is looking into the function of these spaces as a meeting place for various occasions (eg. holding of festivities, place of associational life, leisure activities). In other chapters german and jewish minorities are closer analyzed. Here the thesis focuses on the character of public life of these communities and their coexistence with Czechs. Examined is, among others, the question which aspects that shape the character of Vineards are the particular groups of residents identified with and which of them they considered as their own and how they have symolically inhabited them. Key words: Royal Vineyards, public spaces, festivities, local identity, Czechs, Germans, Jews, 1880 - 1922.
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Les mouvements de terrain du vignoble champenois : approche géomorphologique et hydrologique / Landslides in Champagne vineyards : geomorphological and hydrological approachBollot, Nicolas 09 December 2014 (has links)
Les nombreux mouvements de terrain qui affectent les versants du vignoble champenois sont à l'origine de coûteux dégâts. Les causes de leur déclenchement restent cependant indéterminées. Basé sur une méthodologie pluridisciplinaire, ce travail de recherche vise à comprendre l'origine et le fonctionnement de ces désordres. A l'échelle régionale, deux grands ensembles se distinguent et mettent en avant le rôle de la structure sur les dynamiques géomorphologiques. Au nord, la cambrure de versant domine. D'âge antésaalien, elle s'est produite en phase ana et/ou cataglaciaire. Au sud, dans le secteur de la vallée de la Marne et de ses affluents, 264 glissements de terrain, d'âge tardiglaciaire pour la plupart, sont recensés. A l'échelle du bassin versant, les glissements de terrain se situent dans les secteurs à fort rendement hydrologique. En retour, leur présence modifie la répartition spatiale des sources : les plus profonds constituent une couverture semi-perméable déterminant un aquifère semi-captif. A l'échelle locale, les investigations géophysiques et piézométriques permettent de modéliser les relations hydrogéologiques entre formations superficielle et substrat. Il apparait que les glissements ont une structure très hétérogène, que les circulations d'eau y sont réduites et ralenties dans la masse du mouvement, et enfin que les échanges avec le substrat se produisent le long du plan de cisaillement. Dans ces conditions, l'influence des facteurs climatiques actuels sur la réactivation des glissements est indirecte et faible. / The numerous mass movements affecting the Champagne vineyards slopes cause expensive damages. However, triggering factors are still unknown. Using a multidisciplinary methodology, this research aims to understand the origin and the behavior of these instabilities. At a regional scale, two major groups are distinguished and show the importance of the geological structure on the geomorphological dynamics. Northwards, valleyside cambering of pre-Saalian age predominates. It took place during ana and/or cataglacial phase. Southwards, in the Marne valley and its tributaries area, 264 landslides, most of them dating from Tardiglacial period, are inventoried. At the watershed scale, areas with a high quantity of landslides correspond to the sectors of high hydrological yields. In return, the presence of landslides alters the spatial distribution of springs: deepest landslides constitute a semi-permeable cover leading to semi-confined aquifers. At the local scale, geophysical and piezometric investigations make it possible to model the hydrogeological relationship between superficial formations and substratum. It appears that landslides structure is heterogeneous, that the circulation of water is limited and slow in the landslide, and that the exchanges with substratum occur along the shear plan. Under these conditions, the influence of climatic factors on the current reactivations is both indirect and weak.
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Influence of ripening grape compounds on behavioural responses of birdsSaxton, V. P. January 2004 (has links)
Vineyards in New Zealand suffer bird damage caused by several avian species, including blackbirds and silvereyes. The introduced European Blackbird takes whole grapes which reduces yield. The self-introduced Australasian Silvereye pecks on grapes, leaving them on the vine to be further attacked by fungi and bacteria, and the subsequent off-odours can cause grapes to be refused by the winery or to suffer a price-reduction. Bird control methods remain primitive and largely ineffective during the long ripening period of wine grapes. An ecologically sound method to manage and reduce bird pressure requires deeper understanding of why some birds eat grapes, especially since grapes are not particularly nutritious. This work investigated the extent to which blackbirds and silvereyes are attracted by various compounds in ripening grapes. Since in natural grapes these compounds develop and change simultaneously, I developed an artificial grape in which a single parameter could be investigated. Artificial grapes (and sometimes nectar) were presented on a bird feeder table and the responses of birds to hexose sugars, the aromas 2-3-isobutylmethoxypyrazine and geraniol, tartaric and malic acids, grape tannins, and purple and green colour were recorded on timelapse video and analysed.
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