A Campanha Gaúcha tem sido apresentada como uma região vitivinícola em expansão, mas ainda apresenta uma carência de informações técnicocientíficas locais. Muitos vinhedos apresentam vigor excessivo e desequilíbrio entre crescimento vegetativo e produção, o que pode estar associado a equívocos em densidades de plantio, carga de gemas por planta e manejos de dossel, oriundos de outras regiões vitivinícolas, o que pode restringir a qualidade enológica da uva. O presente trabalho teve por objetivos selecionar algumas referências de espaçamento, carga de gemas (capítulo 1) e proporção de área foliar (capítulo 2) para a cultivar Merlot (Vitis vinifera) enxertada sobre SO4, visando o controle de vigor e o favorecimento da qualidade enológica da uva nesta região. O experimento foi conduzido em Santana do Livramento/RS, nas safras 2013, 2014 e 2015, em um vinhedo implantado em 2007, conduzido em espaldeira, com espaçamento de 1 m x 2,8 m. Para o experimento de carga de gemas foram testados dois espaçamentos na linha (1 m e 2 m) em combinações com variação de carga de gemas por planta, dando origem aos seguintes tratamentos: T1 (20 gemas m-1), T2 (30 gemas m-1), T3 (40 gemas m-1), T4 (60 gemas 2 m-1) e T5 (40 gemas 2 m-1). No experimento de proporção de área foliar, testaram-se despontes com 0,8 m2 kg-1, 1,0 m2 kg-1, 1,4 m2 kg-1, e 1,6 m2 kg-1, antes do véraison (dezembro). Ao longo de cada ciclo foram avaliados fenologia, parâmetros de crescimento, maturação, componentes de rendimento, qualidade enológica da uva e do vinho. A redução da carga de gemas (T1) favoreceu a qualidade, mas não restringiu o vigor vegetativo. Em contrapartida, plantas com espaçamento duplo e maior carga de gemas (T4) apresentaram o melhor equilíbrio vegetativo/produtivo e qualidade enológica da uva e do vinho. Os despontes com 6 fps e 10 fps restringiram o acúmulo de sólidos solúveis totais (SST) e aumentaram o pH e a acidez total titulável (ATT). A partir de 15 fps (1,4 m2 kg-1) não houve restrições na maturação, caracterizando-se como o limite mínimo de folhas principais por sarmento para ser adotado no manejo do dossel da 'Merlot' na Campanha Gaúcha. / The Campanha Gaúcha has been an expanding wine region, but still lacks local technical and scientific information. Many vineyards have excessive vigor and imbalance between vegetative growth and production, which may be associated with suboptimal planting densities, bud load per plant and canopy management, imported from other wine regions, which may restrict the enological quality of grapes. This study aimed to select some spacing references, bud loads (Chapter 1) and proportion of leaf area per plant (Chapter 2) to cultivate 'Merlot' (Vitis vinifera), to control vigor and optimize wine quality in this region. The experiment was conducted in Santana do Livramento/RS (vintages of 2013, 2014 and 2015), in a 6 year-old vineyard (2007), conducted in vertical trellis system, with spacing of 1 m x 2,8 m and SO4 rootstock. For the bud load experiment were tested two spacings within the line (1 m and 2 m) in combination with variations in number of buds per plant, which constituted the following treatments: T1 (20 buds m-1), T2 (30 buds m-1), T3 (40 buds m-1), T4 (60 buds 2 m-1) e T5 (40 buds 2 m-1). In the experiment of leaf area proportion, pre-véraison (December) trimming resulted in 0,8 m2 kg-1, 1,0 m2 kg-1, 1,4 m2 kg-1 e 1,6 m2 kg-1. Throughout each cycle, phenology, growth parameters, maturity, yield components, and enological quality of grapes and wine were evaluated. Bud load reduction (T1) favored quality, but did not restrict vegetative vigor. Plants with double spacing and higher bud load (T4) had the best vegetative/productive balance and enological quality of grapes and wine. Prunings with 6 lps and 10 lps restricted accumulation of total soluble solids (TSS) and increased pH and titratable total acidity (TTA). No restrictions on maturity were observed with 15 lps (1,4 m2 kg-1) or more, characterizing this value as the minimum number of primary leaves per shoot to be adopted in canopy management of 'Merlot' in the Campanha Gaúcha region.

In best-first top-down induction of decision trees, the best split is added in each step (e.g. the split that maximally reduces the Gini index). This is in contrast to the standard depth-first traversal of a tree. The resulting tree will be the same, just how it is built is different. The objective of this project is to investigate whether it is possible to determine an appropriate tree size on practical datasets by combining best-first decision tree growth with cross-validation-based selection of the number of expansions that are performed. Pre-pruning, post-pruning, CART-pruning can be performed this way to compare.

The goal of top-k ranking is to rank individuals so that the best k of them can be determined. Depending on the application domain, an individual can be a person, a product, an event, or just a collection of data or information for which an ordering makes sense. In the context of databases, top-k ranking has been studied in two distinct directions, depending on whether the stored information is certain or uncertain. In the former, the past research has focused on efficient query processing. In the latter case, a number of semantics based on possible worlds have been proposed and computational mechanisms investigated for what are called uncertain databases or probabilistic databases, where a tuple is associated with a membership probability indicating the level of confidence on the stored information. In this thesis, we study top-k ranking with uncertain data in two general areas. The first is on pruning for the computation of top-k tuples in a probabilistic database. We investigate the theoretical basis and practical means of pruning for the recently proposed, unifying framework based on parameterized ranking functions. As such, our results are applicable to a wide range of ranking functions. We show experimentally that pruning can generate orders of magnitude performance gains. In the second area of our investigation, we study the problem of top-k ranking for objects with multiple attributes whose values are modeled by probability distributions and constraints. We formulate a theory of top-k ranking for objects by a characterization of what constitutes the strength of an object, and show that a number of previous proposals for top-k ranking are special cases of our theory. We carry out a limited study on computation of top-k objects under our theory. We reveal the close connection between top-k ranking in this context and high-dimensional space studied in mathematics, in particular, the problem of computing the volumes of high-dimensional polyhedra expressed by linear inequations is a special case of top-k ranking of objects, and as such, the algorithms formulated for the former can be employed for the latter under the same conditions.

No description available.

A Campanha Gaúcha tem sido apresentada como uma região vitivinícola em expansão, mas ainda apresenta uma carência de informações técnicocientíficas locais. Muitos vinhedos apresentam vigor excessivo e desequilíbrio entre crescimento vegetativo e produção, o que pode estar associado a equívocos em densidades de plantio, carga de gemas por planta e manejos de dossel, oriundos de outras regiões vitivinícolas, o que pode restringir a qualidade enológica da uva. O presente trabalho teve por objetivos selecionar algumas referências de espaçamento, carga de gemas (capítulo 1) e proporção de área foliar (capítulo 2) para a cultivar Merlot (Vitis vinifera) enxertada sobre SO4, visando o controle de vigor e o favorecimento da qualidade enológica da uva nesta região. O experimento foi conduzido em Santana do Livramento/RS, nas safras 2013, 2014 e 2015, em um vinhedo implantado em 2007, conduzido em espaldeira, com espaçamento de 1 m x 2,8 m. Para o experimento de carga de gemas foram testados dois espaçamentos na linha (1 m e 2 m) em combinações com variação de carga de gemas por planta, dando origem aos seguintes tratamentos: T1 (20 gemas m-1), T2 (30 gemas m-1), T3 (40 gemas m-1), T4 (60 gemas 2 m-1) e T5 (40 gemas 2 m-1). No experimento de proporção de área foliar, testaram-se despontes com 0,8 m2 kg-1, 1,0 m2 kg-1, 1,4 m2 kg-1, e 1,6 m2 kg-1, antes do véraison (dezembro). Ao longo de cada ciclo foram avaliados fenologia, parâmetros de crescimento, maturação, componentes de rendimento, qualidade enológica da uva e do vinho. A redução da carga de gemas (T1) favoreceu a qualidade, mas não restringiu o vigor vegetativo. Em contrapartida, plantas com espaçamento duplo e maior carga de gemas (T4) apresentaram o melhor equilíbrio vegetativo/produtivo e qualidade enológica da uva e do vinho. Os despontes com 6 fps e 10 fps restringiram o acúmulo de sólidos solúveis totais (SST) e aumentaram o pH e a acidez total titulável (ATT). A partir de 15 fps (1,4 m2 kg-1) não houve restrições na maturação, caracterizando-se como o limite mínimo de folhas principais por sarmento para ser adotado no manejo do dossel da 'Merlot' na Campanha Gaúcha. / The Campanha Gaúcha has been an expanding wine region, but still lacks local technical and scientific information. Many vineyards have excessive vigor and imbalance between vegetative growth and production, which may be associated with suboptimal planting densities, bud load per plant and canopy management, imported from other wine regions, which may restrict the enological quality of grapes. This study aimed to select some spacing references, bud loads (Chapter 1) and proportion of leaf area per plant (Chapter 2) to cultivate 'Merlot' (Vitis vinifera), to control vigor and optimize wine quality in this region. The experiment was conducted in Santana do Livramento/RS (vintages of 2013, 2014 and 2015), in a 6 year-old vineyard (2007), conducted in vertical trellis system, with spacing of 1 m x 2,8 m and SO4 rootstock. For the bud load experiment were tested two spacings within the line (1 m and 2 m) in combination with variations in number of buds per plant, which constituted the following treatments: T1 (20 buds m-1), T2 (30 buds m-1), T3 (40 buds m-1), T4 (60 buds 2 m-1) e T5 (40 buds 2 m-1). In the experiment of leaf area proportion, pre-véraison (December) trimming resulted in 0,8 m2 kg-1, 1,0 m2 kg-1, 1,4 m2 kg-1 e 1,6 m2 kg-1. Throughout each cycle, phenology, growth parameters, maturity, yield components, and enological quality of grapes and wine were evaluated. Bud load reduction (T1) favored quality, but did not restrict vegetative vigor. Plants with double spacing and higher bud load (T4) had the best vegetative/productive balance and enological quality of grapes and wine. Prunings with 6 lps and 10 lps restricted accumulation of total soluble solids (TSS) and increased pH and titratable total acidity (TTA). No restrictions on maturity were observed with 15 lps (1,4 m2 kg-1) or more, characterizing this value as the minimum number of primary leaves per shoot to be adopted in canopy management of 'Merlot' in the Campanha Gaúcha region.

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

Call number: LD2668 .T4 1966 N156 / Master of Science

10 pp. / Pruning recommendations for shrubs commonly planted in the low and mid-elevation desert in Arizona are given based on the intended use and individual plant growth characteristics.

Effects of trellising on water use, absorption of photosynthetically active radiation (PAR, 400 to 700 nm wavelength) by foliage and potentially by fruit, fruit composition, and yield were studied in 1988 under semi-arid conditions on field-grown Vitis vinifera L. 'Petite Sirah' grapevines in a mature vineyard. The positioning of shoots on trellises resulted in canopies that were (1) positioned vertically (vertical canopy), (2) positioned in a "V" pattern with sides inclined 60° from horizontal (inclined canopy), and (3) inclined toward the vineyard floor (standard canopy). Seasonal water use values determined from neutron scattering data were 393 ± 61, 554 ± 73, and 455 ± 57 mm for the standard, vertical and inclined canopies, respectively. On average, about 50% of seasonal water consumption occurred between fruit set and filling stages for each type of canopy. Average crop factors (ratio of actual to reference crop evapotranspiration) of 0.383, 0.540 and 0.444 were for the period bud burst to harvest for standard, vertical and inclined canopy systems, respectively. The diurnal water use patterns of the three trellising canopies were very similar when measured by either the heat pulse technique or by porometer. The average daily heat pulse velocity (HPV) for selected vertical, inclined and standard canopies for 6 days were 8.77, 7.58 and 6.85 cm h⁻¹, respectively. The HPV technique indicated that the average daily water use of the whole plant was 0.227, 0.192 and 0.137 kg/m² leaf area/d for standard, vertical and inclined canopies, respectively. The daily average transpiration rates as measured by the HPV technique were 32, 31, and 25% higher than the average transpiration rates estimated from porometer data for standard, vertical and inclined canopies, respectively. Stomatal conductances of the vertical and inclined canopies were 20 and 40%, respectively, below that of standard canopy. PAR absorption by foliage during mid-day was highest in the standard trellis, and lowest in the inclined trellis. PAR potentially available for absorption by fruits was lowest in the standard trellis, and highest in the inclined trellis. In both inclined and vertical canopies, the average sunfleck values were 26%, but was only 2% in the standard canopy. Analysis of fruit composition at harvest revealed that total dissolved solids (°Brix) was significantly higher in the inclined trellis than for the vertical trellis or the standard trellis. The inclined trellis resulted in the highest alcohol content of wine. Per vine yields did not differ significantly among the three trellis systems. Overall, the standard trellis was optimum because grapevines consumed less water and produced a shading which protected the fruit from direct solar radiation.

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.