Thesis (Ph.D.)--University of Adelaide, School of Earth and Environmental Sciences, Discipline of Soil and Land Systems, 2004. / "October, 2004" Includes bibliographical references (leaves 228-254). Also available in a print form.

Thesis (Ph.D.)--University of Melbourne, Agriculture and Food Systems,Faculty of Land and Food Resources, 2006. / Typescript. Includes bibliographical references.

Thesis (Ph.D.)--University of Adelaide, School of Earth and Environmental Sciences, Discipline of Soil and Land Systems, 2004. / "October, 2004" Includes bibliographical references (leaves 228-254).

Thesis (Ph.D.)--University of Adelaide, School of Earth and Environmental Sciences, Discipline of Soil and Land Systems, 2004. / "October, 2004" Includes bibliographical references (leaves 228-254). Also available in a print form.

Thesis (MScAgric)--University of Stellenbosch, 2005. / Bibliography. Also available via the Internet.

No description available.

Thesis (MScAgric)--University of Stellenbosch, 2005. / ENGLISH ABSTRACT: Wind, as a component of the environment, contributes to the viticultural concept of terroir in the South Western Cape region of South Africa. Many other components also contribute to terroir (e.g. soil, altitude, direction of slope, etc.) and it is difficult to quantify the contribution of each. A good terroir promotes slow and complete ripening of the berries. A vineyard on such a terroir produces good quality crops over time and the effects of climatic extremes on the performance of the vine are limited by this terroir. Although grapevines in the South Western Cape are exposed to strong synoptic southerly and southeasterly winds during the growing season and sea breezes add to the effect of wind in coastal areas, little is known about the effect of wind on grapevine performance. This preliminary study was undertaken to obtain more information on the effect of wind on some morphological and reproductive characteristics of Merlot nair. The aim was to obtain preliminary data which can serve as a basis for future studies on the effect of wind on grapevine performance. Important differences .in wind speed were measured spatially in a selected vineyard and exposure to wind was observed to result in essential viticultural differences. The effect of wind on vegetative parameters, canopy density, yield, berry composition and wine quality was investigated. Wind caused leaves on primary shoots of exposed vines to be smaller, but increased lateral growth in their fruiting zones. Sheltered vines had longer shoots but no significant differences were measured concerning cane diameter and pruning mass. Although it was expected that sheltered vines would have denser canopies, similar canopy densities were measured for both treatments. Vines exposed to wind responded with decreased stomatal conductance. As a result, leaf temperature was affected, showing differences between sheltered and exposed vines. Sheltered vines had more bunches per vine but fewer berries per bunch. As a result, bunches of sheltered vines were smaller than those of exposed vines. No significant difference was observed concerning the yield under the two treatments. The effect of wind on stomatal conductance had an essential impact on berry composition, thus directly influencing the quality of wine. Grapes from exposed vines showed a higher colour index. Berries from sheltered vines had significantly lower pH values and potassium concentrations and the malic acid content was lower than in berries from exposed vines. Wine from sheltered vines had more vegetative undertones in comparison with the stronger fruity character of exposed vines. A better acid balance, together with superior complexity (fullness/mouth feel), contributed to the better overall quality identified during the evaluation of wine produced from sheltered vines. / AFRIKAANSE OPSOMMING: Wind as 'n omgewingsfaktor dra by tot die wingerdkundige konsep van terrair in die Suidwes-Kaap streek van Suid-Afrika. Baie ander komponente dra ook by tot terrair (bv. grond, hoogte bo seespieël, rigting van helling, ens.) en dit is moeilik om die bydrae van elk te kwantifiseer. 'n Goeie terrair bevorder stadige en volledige rypwording van die korrels. 'n Wingerd gevestig op so 'n terrair produseer jaarliks hoë kwaliteit oeste met goeie sapsamestellings en die terrair beperk die negatiewe invloed van uiterste klimaatsomstandighede op wingerdprestasie. Alhoewel wingerde in die Suidwes-Kaap gedurende die groeiseisoen aan sterk sinopties suidelike en suid-oostelike winde blootgestel is en seebriese 'n bykomstige effek in kusgebiede het, is daar beperkte kennis oor die effek wat wind op wingerdprestasie het. Hierdie voorlopige studie is onderneem om meer inligting oor die effek van wind op sommige morfologiese en reproduktiewe eienskappe van Merlot noir in te win. Die mikpunt was om verwysingsdata in te samel wat as 'n basis vir toekomstige studies oor die effek van wind op wingerdprestasie kan dien. Belangrike verskille in windspoed is gemeet in die geselekteerde wingerd en waarnemings het getoon dat blootstelling aan wind tot kenmerkende wingerdkundige verskille gelei het. Die effek van wind op vegetatiewe parameters, lowerdigtheid, oesgrootte, druifsamestelling en wynkwaliteit is ondersoek. Wind het kleiner blare op primêre lote van wind-blootgestelde stokke veroorsaak, maar het laterale groei in hul trossones verhoog. Wind-beskermde stokke het langer lote gehad maar geen noemenswaardige verskille is ten opsigte van lootdeursnee en snoeimassa gemeet nie. Die verwagting was dat beskermde stokke digter lower sal hê, maar soortgelyke lowerdigthede is vir beide beskermde en wind-blootgestelde stokke gemeet. Stokke blootgestel aan wind het met 'n verlaagde huidmondjiegeleiding gereageer. Gevolglik is blaartemperatuur beïnvloed, met verskille tussen beskermde en blootgestelde wingerde. Beskermde stokke het meer trosse per stok maar minder korrels per tros gehad. As gevolg hiervan was die trosse van beskermde stokke kleiner as die van blootgestelde wingerde. Geen noemenswaardige verskille in die oesgroottes is tussen die twee behandelings gemeet nie. Die effek van wind op huidmondjiegeleiding het 'n belangrike impak op druifsamestelling gehad en het daarom 'n direkte invloed op wynkwaliteit gehad. Druiwe van blootgestelde stokke het 'n hoër kleurindeks getoon. Die pH en kaliumkonsentrasie van druiwe van beskermde stokke was merkbaar laer en het minder appelsuur gehad as die van die blootgestelde stokke. Die wyn van beskermde stokke het meer vegetatiewe geure gehad in vergelyking met die sterker vrugtige karakter van blootgestelde stokke. 'n Beter suurbalans, tesame met goeie kompleksiteit (volheid/mondgevoel), het egter meegebring dat beskermde stokke 'n beter wyngehalte lewer.

Thesis (MScAgric)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: In the past it was very difficult to visualise the extent and distribution of variability in growth vigour within vineyards. The advancement of remote sensing technology has changed this however, establishing new methods to assess and manage variability. Even though the causes and effects of within-vineyard variability in growth vigour are complex, new technologies offer better ways of monitoring, researching and managing these factors. In addition to the possible benefits of aerial or satellite remote sensing, new methods of mapping soil spatial variability as well as advances in georeferencing technologies supply precision tools to both researchers and producers. The scientific advancement of the technology, however, is currently the most important aspect needed. This is crucial to answer and explore fundamental questions regarding the use of the technology and the interpretation of results within the framework of the plant's observed reaction. Only then can the possible applications in vineyard management be optimised to address the management problems of extensive within-vineyard variation in growth vigour. The choice will always be to use the technology to manage the observed variability in order to limit the negative impacts of a heterogeneous harvest, or to identify the variability and its causes for the implementation of management practices aimed at a more homogenous vineyard and harvest. Whatever the case, extensive research is needed to provide tight correlations between information gathered with new technologies to assess variability and plant status, such as multi- and hyperspectral analysis, and ground-truthed results in the vineyard. Only then will it become evident which methods and analyses would be useful in the drive towards in-depth analysis and management of vineyards within the concept of precision viticulture and its derived advantages. With this in mind, the aim of this study was to establish an experimental model to use remote sensing technologies to identify and classify within vineyard variability with a subsequent analysis of the causes of variability and the effects on the plants. The targeted experimental model was a vineyard with highly heterogeneous above-ground growth. An aerial photograph of the vineyard was studied and manipulated to yield image pixel values used to quantify the degree of variability for different plots, which were chosen according to different plot layouts. Soil conditions were assessed on both a global and plot level, with extremely high pH and low resistance values in the soil in combination with erratic soil preparation practices found to be the main cause of variability. Soil physicochemical condition was also assessed during a soil profile pit study. Significant differences were found between several soil-related parameters measured for the higher and lower vigour levels and a strong correlation was also found between the resistance of a saturated soil paste and the image pixel values. Vegetative measurements also yielded highly significant differences between the vigour levels and confirmed the suitability of the vineyard to study within-vineyard variability. Some of these measurements were also strongly correlated with soil conditions as well as image pixel values. Trunk circumference proved to be an excellent measure for the level of variability, being linked strongly to canopy characteristics, soil conditions as well as the image pixel values. Leaf water potential measurements also yielded significant differences between the vigour levels. Harvest data and wine analyses showed the effect that vigour differences can have on grape composition and wine quality, even though the differences found here were much less than expected. Even though no clear preference was shown between the wines made from the different vigour levels, the lower vigour wine was considered fruitier. The overall quality of both experimental wines was however very high, considering that experimental winemaking techniques has been used. Hyperspectral measurements also confirmed differences between the vigour levels through a narrow-band NOVI (normalised difference vegetation index). It was also possible to show differences in certain biochemical compounds between the vigour levels on both a leaf and canopy level. Wavelength regions corresponding to carotenoid, chlorophyll a and chlorophyll b showed different spectral reactions in the leaves of more stressed (lower vigour) canopies, indicating possibilities for further studies. This study and its results is the first of its kind in the South African wine industry and paves the way for more focussed and in-depth analyses of the use of specifically multiand hyperspectral data to accurately assess within-vineyard vigour variability and the management thereof to yield optimum quality grapes for a specific wine target. Moreover, the approach adopted in this study is also echoed in other international research programs in prominent wine countries. The availability of scientific research regarding the optimal use and limitations of these technologies has the potential to revolutionise production management practices in the next few years in the viticultural industry. / AFRIKAANSE OPSOMMING: In die verlede was dit baie moeilik om die omvang en verspreiding van groeikragvariasie binne 'n wingerd te visualiseer. Die vordering gemaak op die gebied van afstandswaarneming-tegnologie het egter nuwe metodes beskikbaar gestel waardeur hierdie variasie in wingerde gemonitor en bestuur kan word. Selfs al is die oorsake en invloede van binne-wingerd-groeikragvariasie kompleks, verskaf nuwe tegnologieë verbeterde metodes om hierdie variasie te monitor, te bestuur en na te vors. Saam met die moontlike voordele wat lugfoto's en satelliet-afstandswaarneming teweegbring, verskaf nuwe metodes om ruimtelike variasie in grondfaktore te karteer, asook vordering in geoverwysingstegnologie, presisiehulpmiddels aan produsente én navorsers. Die wetenskaplike vordering van dié tegnologie is tans van groot belang. Die belang daarvan is om fundamentele vrae te ondersoek en te beantwoord rakende die gebruik van die tegnologie en die interpretasie van resultate binne die raamwerk van die waargeneemde reaksie in die plant. Dit sal die weg baan vir optimale toepassing van die tegnologie in wingerdbestuur om sodoende die bestuursprobleme wat deur binne-wingerdgroeikragvariasie teweeggebring word, aan te spreek. Die voorkeurkeuse is om dié tegnologie aan te wend om hierdie variasie te bestuur sodat die negatiewe impak van In heterogene oes teengewerk kan word, of om die variasie te identifiseer vir die implementering van bestuurspraktyke gemik op die skep van 'n meer homogene wingerd en oes. Dit is noodsaaklik dat uitgebreide navorsing gedoen word om noue verwantskappe vas te stel tussen inligting wat ingewin is met behulp van nuwe tegnologieë wat die variasie in plantstatus monitor, soos multi- en hiperspektrale analise, en inligting wat op grondvlak ingewin is. Hieruit sal dit duidelik wees watter metodes en analises die doeltreffendste is vir in-diepte analises en die bestuur van wingerde binne die konsep van presisie-wingerdkunde. Met inagneming van hierdie aspekte, was die doel van hierdie studie om 'n eksperimentele model daar te stel waardeur afstandswaarneming-tegnologie gebruik kan word om variasie binne wingerde te identifiseer en te klassifiseer deur analises van die oorsake van hierdie variasie en invloede op die plant. Die geteikende eksperimentele model was 'n wingerd met hoogs heterogene bogrondse groei. 'n Lugfoto van die wingerd is bestudeer en gemanipuleer om pixelwaardes te verskaf wat die graad van variasie vir verskillende eksperimentele plotte, wat aan die hand van verskillende plotuitlegte gekies is, te kwantifiseer. Grondtoestande is bestudeer op 'n globale én plotvlak, met uiters hoë pH en lae weerstande in kombinasie met verkeerde grondvoorbereidingspraktyke, wat geïdentifiseer is as die hoofoorsake vir die hoë vlakke van variasie. Grondfisiese en -chemiese toestand is ook tydens profielgatstudies bestudeer. Betekenisvolle verskille is gevind tussen verskeie grondverwante parameters gemeet vir plotte met onderskeidelik laer en hoër groeikrag, en 'n sterk verwantskap is gevind tussen grondweerstand en pixelwaardes, soos vanaf die lugfoto bepaal. Vegetatiewe metings het ook betekenisvolle verskille tussen die hoër en laer groeikragvlakke opgelewer, wat die geskiktheid van die wingerd vir die studie van binnewingerdvariasie in groeikrag bevestig het. Van hierdie metings was ook nou verwant aan grondtoestande, asook beeldpixelwaardes. Stamomtrek was 'n uitstekende maatstaf vir die vlakke van variasie, aangesien dit nou verwant was aan lowertoestande, grondtoestande, asook beeldpixelwaardes. Blaarwaterpotensiaal-metings het ook betekenisvolle verskille tussen die hoër en laer groeikragvlakke opgelewer. Oesdata en wynanalise het die uitwerking van groekragverskille op druifsamestelling en wynkwaliteit uitgewys, selfs al was die verskille wat gevind is minder as wat verwag is. Hoewel geen duidelike voorkeur tussen die wyne afkomstig van verskillende groeikragvlakke uitgewys kon word nie, was die wyn wat van die laer-groeikrag stokke gemaak was, meer vrugtig. Die algemene kwaliteit van beide wyne was egter baie hoog as in ag geneem word dat eksperimentele wynmaakprosedures gevolg is. Hiperspektrale metings het ook die verskille tussen groeikragvlakke bevestig deur 'n nou-bandwydte NDVI ("normalised difference vegetation index"). Dit was ook moontlik om verskille in sekere biochemiese komponente tussen die groeikragvlakke op 'n blaar- én lowervlak uit te wys. Golflengte-areas ooreenstemmend met karotenoïed, chlorofil a en chlorofil b het verskillende spektrale reaksies in die blare met hoër stresvlak (laer groeikrag) lowers ten toon gestel. Dit het moontlikhede vir verdere navorsing uitgewys. Hierdie studie en die resultate wat verkry is, is die eerste van sy soort in die Suid- Afrikaanse wynbedryf. Dit baan die weg vir meer gefokusde en in-diepte analise van die gebruik van spesifiek multispektrale en hiperspektrale data om binne-wingerdgroekragvariasie akkuraat te monitor en te bestuur met die oog op optimum wynkwaliteit vir 'n spesifieke produkdoelwit. Die aanslag van hierdie navorsing is ook sigbaar in ander prominente wynproduserende lande. Beskikbaarheid van wetenskaplike navorsing rakende die optimale gebruik en tekortkominge van hierdie tegnologieë het die potensiaal om produksiebestuurspraktyke in die wingerdbedryf in die komende jare te revolusionaliseer.

Thesis (MSc)--Stellenbosch University, 2002. / ENGLISH ABSTRACT: Food demands for the ever-increasing human population is increasing the pressure on the agricultural sector to produce more food. In order to satisfy these demands, farmers are turning to chemical biocides for the control of pest species to produce greater crop yields. All pesticides must be toxic or poisonous to the target species they intend to control. Unfortunately, most pesticides are toxic or poisonous to non-target organisms as well, with detrimental effects on their health. Organic farming was developed to enhance the overall health of the farm's natural soilmicrobe- plant-animal biodiversity. No synthetic fertilisers and/or pesticides are used when farming organically. Life in the soil consists of intricate food webs and interactions between the soil dwelling invertebrates. The soil-organisms are divided into three main groups, viz., Micro-organisms (e.g. protozoa, bacteria and fungi) mesofauna (nematodes, Collembola and Acari) and macro-fauna (e.g. millipedes, isopods, insects, molluscs and earthworms). The invertebrates are very susceptible to chemical contamination by chemical biocides in natural and agro-ecosystems. The soil invertebrate communities are responsible for the decomposition of organic material in soil, thereby remineralising the soil. The decomposition processes start with comminution of the large pieces of organic material by meso- and macro-fauna and ends with the micro-fauna and microbial organisms that complete these processes by returning the nutrients in an inorganic form to the soil. The aim of this study was to investigate whether, and to what extent the soil organisms are influenced by different management practices viz., organic management practices versus conventional management practices. A vineyard on the farm Plaisir de Merle, in Simondium, Western Cape was used for the present study. One half of a one hectare vineyard was managed organically and the other half conventionally. Within each vineyard block six different treatments were performed. Three of the treatments were strictly organic and the other three were strictly conventional. Four replicates of each management treatment were performed. The bait-lamina technique was used to assess the feeding activity of the soil organisms exposed to the different management treatments. In addition to the bait-lamina trials in the vineyard itself, bait-lamina tests were performed in microcosm studies with soil from the organically and conventionally managed vineyard blocks under controlled conditions. In order to assess the impact of the various pesticides that are used in the vineyards in the conventional way, on the soil fauna, standard acute toxicity tests and behavioural tests were performed on Eisenia fetida, the compost worm. The bait-lamina tests in the vineyard revealed that the moisture content of the soil plays an important role in the biological activity of soil fauna. The different management treatments did affect the biological activity of the soil fauna, but seasonal changes also proved to be one of the important factors governing biological processes in the soil. The acute toxicity tests showed that the active ingredients (mancozeb, penconazole and trifloxystrobin) of three of the pesticides that were tested in this study, had negatively affected E. fetida at their recommended application concentrations. The remaining two pesticides' active ingredients (glyphosate and N-acetyl salicylic acid) did not affect the earthworms negatively at the recommended application concentrations. The preference behavioural trials showed that E. fetida could detect and avoid contaminated substrates at the LCso-concentrations of the different pesticides. All the earthworms were influenced positively in the preference behaviour experiments. Because of certain limitations of the bait-lamina technique, it was difficult to formulate conclusions on what happens in the soil. A possible explanation for the differences in feeding activity of soil fauna could be attributed to the migration of the soil fauna to more habitable soil horizons during the dry summer conditions, when most of the pesticides are applied. The ecological relevance of the acute toxicity tests conducted need to be investigated further. It is clear that the acute toxicity tests provided important information that should be considered, but care should be taken and the necessary safety factors be determined and considered when doing risk assessment studies. The results of the preference behaviour studies showed that for certain pesticides E. fetida can be a sensitive bioindicator of acute and/or sub-acute lethal toxicity testing but this might not necessarily be the case for other pesticides. The goal of doing laboratory studies is to gain as much information to make reliable extrapolations to field situations from laboratory data. Laboratory-to-field extrapolations are very complicated because of the physico-chemical composition of soil, the unpredictable way pesticides behave within soil and the reaction of soil organisms to the soil and to the chemical biocides that are used. Further studies need to be done in order to fully understand to what extent the soil fauna were affected by the different management practices applied to the vineyard at Plaisir de Merle. / AFRIKAANSE OPSOMMING: Voedsel aanvraag vir die toenemende menslike bevolking plaas groot druk op die landbou sektor om meer kos te produseer. Om aan die voedsel eise te voldoen, gebruik boere al meer chemiese biosiede om pesspesies te bestry. Alle pestisiede moet toksies of giftig wees vir die teiken organisme waarvoor dit bestem is. Ongelukkig is die meeste pestisiede ook toksies of giftig vir nie-teiken organismes, wat tot nadelige effekte op hul gesonheid kan lei. Organiese boerdery is ontwikkel om die algehele gesondheid van die plaas se natuurlike grond-mikrobe-plant-dier biodiversiteit te bevorder. Geen sintetiese bemestingstowwe en/of pestisiede mag gebruik word wanneer daar organies geboer word nie. Die lewe in die grond bestaan uit ingewikkelde voedselwebbe en interaksies tussen die grondlewende invertebrate. Die grond invertebrate word verdeel in drie hoof groepe, nl. mikro-organismes (bv. Protozoa, bakterieë en fungi) meso fauna (Nematoda, Collembole en Acari) en makrofauna (bv. Millipoda, Isopoda, Insecta, Mollusca en erdwurms). Die Invertebrata is die mees vatbaarste vir chemiese kontaminasie deur chemiese biosiedes in natuurlike en landbou ekosisteme. Die grond invertebraat gemeenskappe is verantwoordelik vir die afbreek van alle organiese materiaal in die grond en dus vir remineralisering van die grond. Die afbreekproses begin by die komminusie van groter stukke organiese materiaal deur die meso- en makrofauna en eindig met die mikrofauna en mikrobes wat die prosesse voltooi deur die nutriente terug te plaas in die vorm van anorganiese produkte in die grond. Die doel van hierdie studie was om te ondersoek of, en tot watter mate, grond organismes geraak word deur verskillende grondbestuurspraktyke, nl. Organiese grondbestuurspraktyke teenoor die konvensionele grondbestuurspraktyke. 'n Wingerd op die plaas Plaisir de Merle, in Simondium, Wes-Kaap, was gebruik vir die huidige studie. Een helfte van 'n een hektaar wingerd is organies bestuur en die ander helfte is op die konvensionele manier bestuur. Op elk van die twee wingerd blokke is ses verskillende behandelings toegepas. Drie van die behandelings was streng organies en die ander drie was streng konvensioneel van aard. Vier replikate van elke behandeling is toegepas op elk van die twee wingerdblokke. Die bait-lamina metode is gebruik om die voedingsaktiwiteit van die grond organismes te asses seer. As toevoeging tot die bait-lamina proewe in die wingerd self, is bait-lamina toetse ook in mikro-kosmosse in die laboratorium gedoen met grond afkomstig vanaf die twee wingerdblokke. Om die impak van die verskillende pestisiede op die grondorganismes te ondersoek, is standaard akute toksisteitstoestse en gedragstoetse uitgevoer met die komposerdwurm, Eisenia fetida. Die bait-lamina resultate in die wingerd het getoon dat die voginhoud van die grond die belangrikste rol speel wat die biologiese aktiwiteit van die grondorganismes beïnvloed. Die verskillende behandelings het die biologiese aktiwiteit van die grond fauna geaffekteer, maar seisoenale veranderings is ook uitgesonder as een van die bepalende faktore wat die biologiese prosesse in die grond stuur. Die akute toksisiteitstoetse het getoon dat die aktiewe bestandeie van drie van die pestisiede (mancozeb, penconazole en trifloxystrobin), E. fetida negatief beïnvloed het teen die aanbeveelde konsentrasies wat toegedien is. Die aktiewe bestandeie van die ander twee pestiede (glyphosate en N-asetiel sallisiel suur) het nie die erdwurms nadelig beïnvloed teen die aanbeveelde konsentrasies wat toegedien is nie. Die gedragsproewe het getoon dat E. fetida die LCso-konsentrasies van al die verskillende pestisiede kan waarneem en vermy. Al die erdwurms is positief beïnvloed in die gedragseksperimente met die verskillende pestisiede. Omdat die bait-laminametode sekere beperkings het, was dit moeilik om tot gevolgtrekkings te kom oor wat presies in die grond gebeur. 'n Moontlike verklaring vir die verskillende voedingsaktiwiteite van die grond fauna kan toegereken word aan die migrasie van die grondorganismes na meer leefbare grondhorisonne gedurende die droë somer toestande, wat toevallig met die spuit van die meeste pestisiede ooreenstem. Die ekologiese relevansie van die akute toksisiteitstoetse wat uitgevoer is, moet meer deeglik ondersoek word. Die belangrikheid van die akute toksisteitstoetse is duidelik en het waardevolle informasie gelewer, maar sorg moet geneem word, en die nodige veiligheids faktore moet bepaal word en in ag geneem word, wanneer riskobepalingstudies gedoen word. Die gedragsproewe het getoon dat vir sekere pestisiede E. fetida 'n sensitiewe bioindikator van akute en/of sub-akute letale toksisiteits toetse kan wees, maar nie noodwendig vir ander pestisiede nie. Die doel van laboratoriumstudies is om so veel as moontlik inligting te versamelom vertroubare ekstrapolasie te kan maak na situasies in die veld vanaf laboratorium data. Laboratorium-na-veld ekstrapolasies is dikwels baie gekompliseerd as gevolg van die fisies-chemiese samestelling van die grond, die onvoorspelbare manier waarop chemiese pestisiede met die grond reageer en die reaksie van die grondorganismes op chemiese biosiede in die grond. Verdere studies moet gedoen word om so deeglik maanlik die mate van die impak wat die verskillende bestuurspraktyke op die grond fauna het, te verstaan op Plaisir de Merle.

Much public attention has been given lately to the concept of sustainability, a notion which is increasingly viewed as a desirable goal of viticulture development and environmental management. The emergence of the sustainability concept has seen a concomitant rise in the interest of its measurement. It has been suggested that through the analysis of regulatory and non-regulatory methods, the attainment of how sustainable freshwater use in vineyards can be assessed. Regulation has to date been the policy tool of choice in regards to environmental protection. While regulation is often necessary, non-regulatory approaches may, in some circumstances, serve as useful supplements to an effective regulatory regime. There are a number of stages to achieving the aim of this research. The first is designed at galvanising New Zealand‟s will to stride out down the sustainability road through the development of the sustainable vineyard concept. Investigations into regulatory freshwater policies were undertaken to assess the relative efficacy of such methods in guiding vineyards in sustainable freshwater use. The research then explored the elements of freshwater use as they relate to non-regulatory methods for achieving sustainable environmental outcomes. Qualitative research was undertaken through the instigation of an email questionnaire and semi-structured interviews to provide an understanding of freshwater use in vineyards within Marlborough. The research focuses on the discussion of the methodological considerations which are important in developing a working framework for assessing how vineyards achieve sustainable freshwater use. The ideal properties and characteristics of sustainability are identified and critically examined. An evaluation of the different types of regulatory and non-regulatory policies on freshwater management are considered. Both regulatory and non-regulatory methods were seen to be significant in developing an operational framework, as they are capable of representing the management of freshwater use and sustainability practices in vineyards. It is observed that the policy goal of both regulatory and non-regulatory organisations in achieving sustainable freshwater outcomes generally cannot be attained to the full satisfaction of all the dimensions of sustainability. Rather, sustainable freshwater use could be considered as a „road‟ and not a fixed destination. Along the way, trade-offs and balances have to be made. It is up to individual vineyard managers to weight the various alternatives, with the policy and decision makers providing information upon which rational choices can be based. This research demonstrates the efficacy of regulatory and non-regulatory methods in guiding sustainable environmental outcomes. It appears that the „ideals‟ of policies, as outlined in the literature and data collected, recommend an overall adaptive management approach if achieving sustainable freshwater use is the ultimate goal.