Le travail de recherche présenté concerne l'étude des pulvérisations de produits phytosanitaires. Les études réalisées au début de ma carrière (ma thèse et les travaux qui en ont découlé) concernent le développement, la validation puis le transfert d'un modèle de calcul de la répartition des dépôts au sol, pour des pulvérisateurs à rampe. Ce travail a servi de base à la définition des méthodologies mises en place par la suite.<br />L'étude de la pénétration de la pulvérisation dans la vigne a ensuite été étudié. Un modèle a été développé à l'aide d'outils commerciaux de CFD pour la représentation du flux d'air dans la végétation et le calcul de trajectoires représentatives de gouttes. Le modèle a été paramétré à partir de mesures de vitesses d'air de part et d'autre de la canopée. Le comportement des nuages de gouttes et la proportion de produit retenue par le feuillage a été développé de manière plus détaillée : le modèle s'appuie sur un coefficient d'efficacité obtenu à partir d'autres simulations. Ces simulations ont été conçues de manière à permettre une<br />validation expérimentale. Les mesures de dépôt réalisées en conditions réelles ont ensuite permis de discuter des résultats du modèle global ainsi que des limites de l'approche.<br />Enfin des contaminations atmosphériques pendant les applications ont fait l'objet d'une démarche expérimentale pour mettre en évidence les relations entre les variables météorologiques, les paramètres-machine et les émissions de pesticide. L'analyse par des systèmes d'inférence floue ont débouché sur une proposition d'outil d'expertise. Un modèle dédié a par ailleurs été développé pour simuler les quantités émises ainsi que leur dispersion atmosphérique.

Au cours des vingt dernières années, l'industrie vitivinicole mondiale a connu certains changements en ce qui concerne les divers agents économiques qui la composent. Ainsi le marché international du vin a été témoin de l'émergence d'entreprises productrices localisées dans les vallées vitivinicoles de l'Afrique du Sud, de l'Argentine, de l'Australie, du Chili et des États-Unis. Cette situation n'est pas étonnante, étant donné que ces pays avaient déjà une certaine expérience dans la production de vin pour le marché local. Cependant, en observant la présence de vins fins d'exportation en provenance de ces pays, dans divers concours œnologiques et dans des revues spécialisées, une question se pose quant aux facteurs qui ont permis à ces pays de se positionner sur des marchés internationaux exigeants. Dans ce contexte, la présente recherche essaie de comprendre les facteurs (économiques, institutionnels et technologiques) qui ont permis une amélioration dans la qualité des moûts et par conséquent, leur acceptation sur les marchés internationaux exigeants en qualité. De manière plus précise, nous nous demandons : De quelle manière, des facteurs comme les sources, les types et les canaux de transfert de la connaissance technique utilisée dans les secteurs du vin et œnologiques, ont-ils influencé la croissance de l'industrie du vin de l'Argentine, du Canada et du Chili? La réponse à cette question a été structurée en considérant des éléments théoriques de la perspective évolutionniste, perspective qui considère le changement et la dynamique comme des éléments centraux de son analyse et qui intègre des variables économiques comme des phénomènes institutionnels. Ainsi, les concepts théoriques associés aux formes d'apprentissage, à la connaissance et aux canaux de transfert technologique ont été fondamentaux lors de la structuration d'un cadre conceptuel qui permet de déterminer l'influence de l'origine de la connaissance et d'autres facteurs administratifs dans la qualité vitivinicole ainsi que les formes de transfert de connaissances les plus utilisées par l'industrie dans ces pays. Le travail empirique s'est concentré sur les vallées de Mendoza (Argentine), Colchagua, Curicó et Maule (Chili) et Okanagan (Canada). À l'aide de données d'enquête sur le terrain (sources primaires) et de données secondaires (Organisation Internationale du Vin, Scopus), nous avons constitué une base de données. Ces informations ont été analysées à travers différentes tests statistiques paramétriques et non paramétriques. Les résultats obtenus permettent de conclure que l'origine de la connaissance n'est pas un facteur décisif, lorsque vient le moment d'augmenter ou de diminuer la qualité des vins. Il y aurait ainsi d'autres mécanismes qui permettraient d'obtenir de meilleures qualités de vins, par exemple le développement d'un processus d'imitation. Toutefois, le développement d'un processus d'imitation implique qu'il soit aussi nécessaire de développer en même temps la recherche et le développement (R-D). Cette activité entraîne, non seulement de nouvelles découvertes ou des améliorations de croissance, mais permet aussi de développer des capacités techniques dans la ressource humaine, et permet de développer les capacités pour adopter ou imiter une nouvelle technologie. Aussi, à la différence de plusieurs autres industries, dans le secteur du vin la taille de l'entreprise est liée aux volumes produits et pas nécessairement avec la qualité produite. Finalement, les résultats ont montré que les entreprises situées dans des pays qui présentent un écosystème d'institutions de science et de technologie bien formé et consolidé, utilisent des canaux plus formels et directs de transfert technologique. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : perspective évolutionniste, formes d'apprentissage, connaissance technologique, canaux de transfert technologique et processus d'imitation.

Les versants viticoles de Côte d'Or (Bourgogne, France) sont soumis aux effets conjugués de processus de ruissellement et de pratiques culturales intenses. Cette étude s'est intéressée à quantifier la dynamique de redistribution des sédiments sur plusieurs échelles de temps et d'espace. Des bilans sédimentaires ont permis de montrer que les versants étudiés, dont les sols sont rendus très sensibles aux phénomènes de ruissellement par la viticulture, sont soumis à des vitesses d'érosion de l'ordre de plusieurs millimètres par an. Les distances de transfert des sédiments associés à l'initiation et au développement des rigoles sont dépendantes d'un seuil de ruissellement. L'existence de ce seuil a été vérifiée dans l'analyse de la distribution spatiale des vitesses d'érosion et de la distribution temporelle des séquences pluviométriques. Le forçage anthropique se manifeste paradoxalement de deux manières : d'abord par l'ablation des sols sur les coteaux, et ensuite par la compensation partielle ou totale de l'érosion, notamment par les remontées de terre. Cet équilibre est à l'origine de la variabilité de la dynamique sédimentaire sur les versants étudiés.

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Doctor of Philosophy (PhD) / My starting point for this thesis was the absence of a foundation history of Australian wine growing conducted by an historian rather than researchers in other disciplines or the media. I have used existing work on wine history in New South Wales from 1788 to 1901 alongside a significant body of new research to create an historical argument suitable for incorporation into more broadly-themed narratives of Australian history and to inform studies of wine growing in other academic fields. My main argument is that although wine growing proved of little economic value in colonial primary production compared with nation-building commodities - such as pastoralism, wheat growing and gold - advocates of the cultivation of wine grapes believed wine growing embodied beneficial, even transformative, cultural value so they persisted in attempting to create a ‘civilizing’ industry producing a ‘civilized’ drink despite lacklustre consumption of their product and very modest profits. Several times, from 1788 to 1901, these advocates spoke out or wrote about wine and wine growing as capable of creating order in a wild or ‘savage’ landscape and within a settler society shaped culturally by shifting adaptations to both imported and ‘native’ influences in agriculture as well as alcohol production, consumption and distribution. While the methodological framework employed here falls mainly within cultural and economic history, sociological theories have contributed to findings on causation. The result is a comprehensive narrative of colonial wine growing in New South Wales enriched by links to key developments in Australian colonial history and with reference to wine growing in other British colonies or former territories.

Copies of author's previously published articles inserted. / Bibliography: leaves 143-167. / xvi, 176 leaves, [17] leaves of plates : ill. (chiefly col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Temperature may affect fruit-set in grapevines through its effect on the development of the flowers up to flower opening and on pollination, be it on the germination of the pollen and the growth of the pollen tube, or on the post-fertilisation growth of the ovule. / Thesis (Ph.D.)--University of Adelaide, Dept. of Horticulture, Viticulture and Oenology, 1996

Includes bibliographies. / vi, 176, 29 p. : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis describes an irrigation experiment established on Vitis vinifera cv. Shiraz in a mature vineyard in the Australian Murray-Darling basin. It concentrates on the relationship between the timing of the water deficit and the depth of irrigation applied and the difference in berry weight between different irrigation treatments. The study includes a polynomial equation which describes the relation between growing degree days and ?p0?sBrix. A two phase linear model is used to describe the change in red-free glycosyl-glucose (G-G). / Thesis (Ph.D.)--University of Adelaide, Dept. of Horticulture, Viticulture and Oenology, 1997

Bibliography: leaves 185-200. / xvi, 200 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / The herbicides norflurazon, oxadiazon, oxyfluoren, trifluralin and simazine used in South Australian viticulture were assessed for mobility and degradation through a combination of laboratory and field experiments. Sorption, leaching and dissipation rates were measured, as was presence in shallow groundwater. The fate of herbicides from vine to wine was also investigated, tests being conducted on herbicide residue in both white and red grapes and presence in wine. A proposal for good environmental management of herbicide use in vineyards to minimise the effects of herbicides was also developed. / Thesis (Ph.D.)--University of Adelaide, Dept. of Environmental Science and Management, 2000

Bibliography: leaves 185-200. / xvi, 200 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / The herbicides norflurazon, oxadiazon, oxyfluoren, trifluralin and simazine used in South Australian viticulture were assessed for mobility and degradation through a combination of laboratory and field experiments. Sorption, leaching and dissipation rates were measured, as was presence in shallow groundwater. The fate of herbicides from vine to wine was also investigated, tests being conducted on herbicide residue in both white and red grapes and presence in wine. A proposal for good environmental management of herbicide use in vineyards to minimise the effects of herbicides was also developed. / Thesis (Ph.D.)--University of Adelaide, Dept. of Environmental Science and Management, 2000

Growth, productivity and fruit quality of grapevines are closely linked to soil water availability. Withholding of water for any length of time results in slowed growth. If drought continues yield may be lost. Vines can be manipulated to stimulate early defence mechanisms by decreasing soil water availability. By using an irrigation technique, which allows for separate zones with different soil moisture status, it is possible to stimulate response mechanisms of the root system which are normally related to water stress. The difficulty of separating 'wet' and 'dry' zones was initially overcome by using split-root plants with root systems divided between two containers. Such experiments on split-root model plants resulted in the development of an irrigation technique termed partial rootzone drying (PRD). Results from irrigation experiments using PRD have shown that changes in stomatal conductance and shoot growth are some of the major components affected (Dry et al., 1996). The idea of using irrigation as a tool to manipulate stress responses in this way had its origin in the concept that root- derived abscisic acid (ABA) was important in determining stomatal conductance (Loveys, 1984). Later experiments on split-root plants have demonstrated that many effects of water stress can be explained in terms of transport of chemical signals from roots to shoots without changes in plant water status (Gowing et al., 1990). The necessary chemical signals are provided by the dry roots, and the wet roots prevent the development of deleterious water deficits. The general hypothesis tested during this study was that partial drying of the root system gives rise to a change in the supply of root-derived chemical signals which determine changes in grapevine physiology, thereby affecting fruit quality. Experiments were conducted on split-root vines (Vitis vinifera L. cvs. Cabernet Sauvignon and Chardonnay) grown in pots of different sizes, on field-grown vines which had either their root system divided by a plastic membrane (Vitis vinifera L. cv. Cabernet Sauvignon on own roots or grafted on Ramsey rootstocks) or conventional vines with a non-divided root system (Vitis vinifera L. cv. Cabernet Sauvignon, Shiraz and Riesling) with a commercial PRD irrigation design. The irrigation treatments were vines receiving water on both sides (control) and PRD-treated vines, which only received water on one side at any time. The frequency of alternation of 'wet' and 'dry' sides was determined according to soil moisture and other influences such as rainfall and temperature. In most of the experiments the irrigation was alternated from one side to the other every 10 to 15 days. Chemical signals from roots: the role of ABA and cytokinins Studies on chemical signals have concentrated on ABA and cytokinins (CK). An improved stable isotope dilution protocol, which enables analysis of ABA and CK from the same tissue sample, was developed. Analysis of cytokinins focused on zeatin (Z), zeatin riboside (ZR), zeatin glucoside (ZG) and iso pentenyl adenine (iP). Roots are relatively inaccessible, particularly in field situations. To enable easier access to roots of field-grown vines, split-root vines were planted in a trench which was refilled with a sandy soil. This created a homogenous soil substrate and did not restrict root growth while still allowing access to roots under field conditions. Analyses of root samples of field-grown vines have shown that cytokinins and ABA may originate in roots and their concentrations can be substantially altered during an irrigation cycle. Alternating soil water conditions showed that [ABA] in roots on the 'dry' side was significantly higher compared with the 'wet' side. Due to a reduction in CK on the 'dry' side of PRD-treated vines, the ratio between ABA and CK was substantially changed during an irrigation cycle. The ABA levels in root tissue and in petiole xylem sap were negatively related to stomatal conductance. This further suggests that ABA, mostly synthesized on the 'dry' side of the root system, might be responsible for a decline in stomatal conductance. Furthermore, a higher pH of petiole xylem sap was observed in PRD-treated vines which may also contribute to the regulation of stomatal conductance. Studies on stomatal patchiness showed that non-uniform stomatal aperture occurred in field-grown vines under natural environmental conditions and was more abundant under PRD conditions. The degree of stomatal opening, determined by using a water infiltration technique, correlated with measurement of stomatal conductance. Exogenous application of a synthetic cytokinin (benzyl adenine) can override the possible ABA-mediated stomatal closure resulting from PRD treatment, providing further evidence for the in vivo role of these growth regulators in the control of stomatal conductance. The effect of benzyl adenine was transient, however, requiring repeated applications to sustain the reversal. In addition, CKs may also be important in influencing grapevine growth. Following several weeks of repeated spray applications with benzyl adenine, it was found that the development of lateral shoots in PRD-treated vines was enhanced compared to PRD-treated vines sprayed with water only. This supports the idea that the reduction in lateral shoot development seen in PRD-treated vines is due to a reduced production of CKs (Dry et al., 2000a). By measuring shoot growth rate it was found that one common feature of PRD-treated vines, which were not sprayed with CK, was a reduction of lateral shoot growth. It can therefore be speculated that the reduction in lateral growth is related to a reduced delivery of cytokinins from the roots. Zeatin and zeatin riboside concentration in shoot tips and prompt buds/young lateral shoots were reduced by the PRD treatment providing further evidence in support of this hypothesis. Water movement from 'wet' to 'dry' roots Roots, being a primary sensor of soil drying, play an important role in long- and short-term responses to PRD. Using stable isotopes of water and heat-pulse sap flow sensors water movement was traced from wet to dry roots in response to PRD. The redistribution of water from roots grown in a soil of high water potential to roots growing in a soil of low water potential may be of significance with regard to the movement of chemical signals and the control of water balance of roots. Measurements of the relative water content (RWC) have shown a slower decline of RWC of the 'dry' roots of PRD vines relative to roots of vines which received no water, despite similar water content in soil surrounding those roots. The redistribution of water may help to sustain the response to PRD for longer periods possibly releasing chemical signals and to support the activity of fine roots in drying soil. Field vines, irrigated with PRD over several growing seasons, altered their root distribution relative to the control vines. PRD caused a greater concentration of fine roots to grow in deeper soil layers and this may contribute to a better water stress avoidance. The effect on root growth may be augmented by the water movement and by the large difference in ABA to cytokinin ratio, which are also known to alter root growth. PRD makes more efficient use of available water In experiments where both control and PRD-treated vines received the same amount of water many differences between the vines were demonstrated. Under conditions where water supply was adequate for both treatments, the stomatal conductance and growth of the PRD-treated vines was restricted as has been observed in many previous experiments. As total water input was reduced, however, the stomatal conductance of PRD-treated vines became greater than control vines, suggesting that the latter were experiencing a degree of water stress, whereas the PRD-treated vines were not. This may have been due to the greater depth of water penetration in the case of the PRD-treated vines, where water was applied to a smaller soil surface area. This distinction between PRD-treated and control vines, at very low water application rates, was also reflected in pruning weights and crop yields which were actually greater in PRD-treated vines. It was concluded that at low water application rates, the PRD-treated vines were more tolerant of water stress and made more efficient use of available water. Reduction in vigor opens the canopy. The initial aim of the research which led to the development of PRD was to achieve better control of undesirable, excessive shoot and foliage growth which, from a viticultural point of view, has many disadvantages. Grapevine shoot growth rate responds very sensitively to drying soil conditions. The irrigation strategy used in the PRD experiments maintained a reduction of both main shoot and lateral shoot growth. In response to PRD a decrease in shoot growth rate and leaf area was observed. Much of the reduction in canopy biomass was due to a reduced leaf area associated with lateral shoots, thus influencing the canopy structure. This was one major factor improving the light penetration inside the canopy. Control of vegetative vigour results in a better exposure of the bunch zone to light and, as a consequence, in improved grape quality. It is likely that changes in canopy density, as a result of PRD, is causing changes in fruit quality components. Anthocyanin pigments such as derivatives of delphinidin, cyanidin, petunidin and peonidin were more abundant in berries from PRD vines; by comparison the concentration of the major anthocyanin, malvidin, was reduced. When leaves were deliberately removed from more vigorous control vines, which improved bunch exposure, the differences in fruit composition were much reduced. This further supports the idea that a more open canopy, in response to PRD, improves fruit quality by affecting the canopy structure. Fruit quality consequently determines the quality, style and value of the finished wine. Wines from this study have been produced and data on wine quality from commercial wineries are also available. Sensory evaluations have demonstrated that high wine quality from PRD-treated vineyards can be achieved without any yield-depressing effects. This study has provided evidence to support the original hypothesis. The major findings were: a) Chemical signals, altered under PRD and mostly originating from roots, play an important role in the root to shoot communication in grapevines. b) The movement of water from 'wet' to 'dry' soil layers may help to sustain chemical signals as a response of grapevines to PRD and to support the activity of fine roots in drying soil. c) A reduction in vegetative growth, in particular of lateral shoots, was sustained using PRD and affected the canopy structure which in turn, due to a better light penetration into the canopy, improved the fruit quality. d) The reduction in irrigation water applied did not have a detrimental effect on grape yield and thus the efficiency of water use was improved. e) Application of relatively low irrigation rates showed that PRD-treated vines were more tolerant of water stress and made more efficient use of available water. / Thesis (Ph.D.)--Department of Horticulture, Viticulture and Oenology, 2000.