Water is a scarce resource worldwide and a particular problem for producers of wine grapes in Australia and Chile where periodic drought severely limits vine growth. Most vineyards in these countries are irrigated and the development of efficient water management practices for vineyards is required. Strategies such as regulated deficit irrigation (RDI) and partial root zone drying (PRD) have been introduced with the objective of maximising the efficiency of water use relative to yield while ensuring that grape quality is not compromised. The problem is that the advantages of these strategies can only be realised if there is accurate information about weather parameters, spatial distribution of soil moisture and vine water use and status. This information can then be used to provide answers for growers to the key irrigation questions of when to irrigate and how much water to apply. The overarching hypothesis of this thesis was than an integrated approach to irrigation scheduling incorporating data on weather, physiological status of the vines and soil wetting patterns is essential to accurately target the narrow range of soil moisture and vine stress thresholds required for realising the advantages of RDI and PRD. The hypothesis was tested through a series of field experiments. The results supported that an integrated approach to irrigation produces the most desirable outcomes in terms of water use and berry quality irrespective of irrigation strategies. The most appropriate way to answer the question of when to irrigate is to measure stem rather than leaf water potential. The question of how much water to apply can readily be answered using a new technique and software developed in this study. It was concluded that PRD is more difficult to manage than RDI because of the complexity pf PRD and the financial and logistic requirements of a double irrigation line. PRD had no effect on crop water use efficiency, berry quality or yield when the same amount of water was applied in the PRD and conventional drip treatments. / Doctor of Philosophy (PhD)

Modern canopy management practices and irrigation strategies have improved the economic and environmental sustainability of Australia ' s wine industry, in terms of increased production and improved wine quality for minimal production cost and environmental impact. This study tested the hypothesis that partial rootzone drying ( PRD ) integrated with low input, minimal pruning practices can improve sustainability of winegrape production in warm - climate, irrigated vineyards. The bi - factorial experiment investigated three conventional pruning practices; hand spur pruning ( SPUR ), mechanical hedging ( MECH ) and minimal pruning ( MIN ) integrated with standard drip ( SD ) and PRD irrigation strategies. The sustainability of winegrape production of field - grown cv. Shiraz grapevines was determined by examining yield, fruit composition, wine composition and quality, vine physiology and susceptibility of bunches to Botrytis bunch rot. Winegrape production was strongly influenced by pruning level and the resultant bunch number per vine. Increased node retention at pruning of minimal pruned vines resulted in 4 - fold more bunches per vine than spur pruned vines. Mechanical hedged vines had an intermediate number of bunches per vine. Yield generally reflected the trend in bunch number per vine. However, minimally pruned and mechanically hedged vines compensated for greater carbohydrate partitioning between reproductive sinks by producing smaller bunches with fewer berries per bunch. Partial drying of the grapevine rootzone had a detrimental effect on yield relative to SD irrigation ( 18 % ). The additive effect of SD combined with light pruning treatments resulted in few statistically significant interactions for the measured yield components. Berry weight was the only parameter influenced by the interaction between irrigation and pruning during the three experimental seasons ; PRD + MIN reduced berry weight by 36 % compared to SD + SPUR, in response to lower irrigation inputs and higher bunch number. A 2 - fold increase in water use efficiency ( tonnes per megalitre ) was found by the reduced irrigation inputs of PRD combined with the high crop levels of MIN vines compared to SD + SPUR vines. Fruit and wine composition was also largely unaffected by combined irrigation and pruning treatments, as a result of the additive effect of PRD and MIN. However, light pruning levels ( MIN and MECH ) and their associated small berry size and high bunch exposure, reduced pH and increased titratable acidity, and anthocyanin and phenolic concentrations of berry juice compared to SPUR. Minor pruning level effects on wine composition can be directly correlated with those observed on fruit composition. PRD had minimal effect on basic fruit composition but strong effects on wine spectral parameters : density, hue, total anthocyanin and phenolic concentration and ionised anthocyanin concentration, possibly as a result of co - pigmentation of anthocyanin compounds with exocarp tannins. Berry size was strongly correlated with fruit and wine quality. Small berries ( i.e. from PRD and MIN ) had lower pH and higher anthocyanin and phenolic concentrations in the juice and produced wine that was more acidic, brighter and had higher colour density and anthocyanin ( total and ionised ) and phenolic concentrations than all other treatments. Midday and diurnal leaf gas exchange were manipulated by partially drying the rootzone. PRD reduced midday stomatal conductance, photosynthesis and transpiration compared to SD. Stomatal limitation on photosynthesis and transpiration was probable, given the strong positive relationship with stomatal conductance and reduced carbon isotope discrimination by PRD. Transpiration efficiency was improved for PRD irrigated vines compared to SD irrigated vines. Leaf water potential and osmotic potential were measured diurnally, in conjunction with leaf gas exchange to investigate the response of PRD irrigated vines to increasing vapour pressure deficit. Diurnally, stomatal conductance was reduced by PRD compared to SD, which maintained leaf water potential, while no osmotic adjustment occurred. Therefore, PRD irrigation maintained hydraulic water status by hydrating half of the rootzone, whilst dehydration of the other half of the rootzone resulted in the partial closure of stomata. Pruning treatment effects on vine physiology were less pronounced. Minor gas exchange effects showed that pruning level influenced carboxylation efficiency and not stomatal limitations, as photosynthesis was not directly correlated with stomatal conductance. Bunches were least resistant to infection by Botrytis when fully developed and at maximum maturity. The development of bunches into tighter clusters as berry size increased from veraison to harvest and the increase in sugar content may have encouraged development of Botrytis. The distinct bunch architecture resulting from the combined pruning and irrigation treatments influenced the incidence and severity of Botrytis bunch rot. Light pruning combined with PRD irrigation produced small, loose bunches in season 2001 - 02, which were less susceptible to Botrytis bunch rot development compared to the large, compact bunches produced on SD + SPUR vines. However, low bunch numbers and high fruit - set on MIN and MECH vines in season 2002 - 03 led to a significant change in bunch architecture. As a consequence of the increased compactness of bunches in season 2002 - 03, no pruning effects on Botrytis development were observed. Long term economic and environmental sustainability of winegrape production is dependent on continual improvement in fruit and wine quality, preservation of yield, reduced water and chemical usage. This study has shown partial drying of the rootzone combined with light pruning techniques improved yield, fruit and wine composition, water use efficiency and transpiration efficiency and reduced the incidence and severity of Botrytis bunch rot compared to SD and severe pruning levels. Therefore, over the three experimental seasons, PRD combined with minimal pruning was determined as the preferred strategy to enhance the sustainability of winegrape production of Shiraz cv. in warm - climate, irrigated vineyards. / Thesis (Ph.D.)--School of Agriculture and Wine, 2004.

Texte remanié de: Thèse de doctorat--Droit public--Reims, 2006.

Thesis (M.S.)--Missouri State University, 2009. / "May 2009." Includes bibliographical references (leaves 100-104). Also available online.

This study, based on data collected in 2006, examined the effect of microclimate, as solar aspect, on yield and quality parameters of Riesling vines of a vineyard in the Niagara Peninsula, Thirty Bench Winery, Beamsville, Ontario. Precision viticulture practices including GPS (Global Positioning System), GIS (Geographic Information System) and LIDAR (Laser Range Finder) were used to delineate the microclimate and categorize variations within the vineyard. Within GIS, slope and aspect analysis tools generated solar aspect data. Two different zones were identified and compared for yield and quality data. Monoterpene concentrations in grapes differed by solar aspect, with vines receiving elevated solar radiation showing increased monoterpene concentrations. Since monoterpenes are important to the aroma and flavour of Riesling wines, a difference could impact the quality of the wine produced. Overall, this work shows the potential of precision viticulture in the development of terroir –specific wine in the Niagara region.

Vineyards are perhaps one of the most attractive and recognizable productive landscapes, comprising 12 000 hectares of Canada’s 998 467 000 hectares of total land area. These unique and beautiful landscapes are characterized by their distinctive site planning, unique micro-climates and an understanding of the terroir of the land. However, the profession of landscape architecture remains tenuously connected to viticulture (the cultivation of grapes) and vineyard designs. Very few landscape architects are involved with the design of vineyards and little to no literature has been written on the interface between these two professions. The intent of this practicum is to articulate and demonstrate the important contribution that landscape architecture can make to viticulture by examining aesthetic values that link site and terroir to create an overall vineyard experience. Through a case study analysis of winery and vineyard sites, this practicum examines how landscape architecture can contribute to viticulture and enhance not only the experience of being in a vineyard setting but also the wine tourism industry. The result is a design for a winery and vineyard site in the Okanagan Valley that employs strategies for improving tourism by enhancing visitor experience.

Vineyards are perhaps one of the most attractive and recognizable productive landscapes, comprising 12 000 hectares of Canada’s 998 467 000 hectares of total land area. These unique and beautiful landscapes are characterized by their distinctive site planning, unique micro-climates and an understanding of the terroir of the land. However, the profession of landscape architecture remains tenuously connected to viticulture (the cultivation of grapes) and vineyard designs. Very few landscape architects are involved with the design of vineyards and little to no literature has been written on the interface between these two professions. The intent of this practicum is to articulate and demonstrate the important contribution that landscape architecture can make to viticulture by examining aesthetic values that link site and terroir to create an overall vineyard experience. Through a case study analysis of winery and vineyard sites, this practicum examines how landscape architecture can contribute to viticulture and enhance not only the experience of being in a vineyard setting but also the wine tourism industry. The result is a design for a winery and vineyard site in the Okanagan Valley that employs strategies for improving tourism by enhancing visitor experience.

Thesis (M. Ag. Sc.)--University of Adelaide, 1986. / Includes bibliographical references (leaves 79-83).

Thesis (Ph. D.)--University of Adelaide, Dept. of Horticulture, Vviticulture (sic) and Oenology, 1996? / Copies of author's previously published articles inserted. Includes bibliographical references (leaves 143-167).

Thesis (M.Env.St.)--University of Adelaide, Mawson Graduate Centre for Environmental Studies, 1998. / Bibliography: leaves 165-170.