O teor de montmorilonite é um parâmetro influente do desenvolvimento e rendimento da videira no Sul do Uruguai

Soil physical and chemical characteristics play a key role on vine growth and yield. The soils of South Uruguay display high content of montmorillonite or illite. The proportion of these minerals deserves special attention as they influence the soil structure and its hydrological properties. The present study was conducted in a 1.1 ha vineyard of this region (Canelones), characterized by a high heterogeneity of plant vigour. It was aimed to determine and map the physical and chemical properties of the soil and their relations with plant vigour and yield. The cation exchange capacity (CEC) and the clay and organic matter contents were measured in 84 locations within this vineyard to calculate the montmorillonite and illite contents of the soil. In addition, the type and abundance of clays was corroborated by X-ray diffractometry analysis. The CEC and montmorillonite contents were positively correlated with vine vigour, expressed by the Normalized Vegetation Index (NDVI), trunk diameter, pruning weight, leaf area, and with yield. Thus, the within vineyard distribution of the ratio montmorillonite/illite conditioned the heterogeneity of vine growth and yield at the field level. The impact of those minerals on water and mineral supply to the plant is discussed.Las características físicas y químicas del suelo desempeñan un papel fundamental en el crecimiento y el rendimiento de la vid. Los suelos del sur de Uruguay presentan un alto contenido de montmorillonita o illita. Las proporciones de estos minerales merecen especial atención ya que influyen en la estructura del suelo y en sus propiedades hídricas. El presente estudio se realizó en un viñedo de 1,1 ha de esta región (Canelones), caracterizado por una alta heterogeneidad de vigor de las plantas. El objetivo fue determinar y cartografiar las propiedades físicas y químicas del suelo, y su relación con el vigor de las plantas y el rendimiento. La capacidad de intercambio catiónico (CEC) y los contenidos de arcilla y materia orgánica se midieron en 84 lugares de este viñedo para calcular los contenidos de montmorillonita e illita del suelo. Además, se corroboró el tipo y la abundancia de arcillas mediante análisis de difractometría de rayos X. Los contenidos de CEC y de montmorillonita se correlacionaron positivamente con el vigor de la vid, expresado por el índice de vegetación normalizado (NDVI), el diámetro del tronco, el peso de la poda, el área foliar y con el rendimiento. Así, la distribución dentro del viñedo de la relación montmorillonita/ilita condicionó la heterogeneidad del crecimiento de la vid y del rendimiento a nivel de campo. Se discute el impacto de estos minerales en el suministro de agua y minerales a la planta.As características físicas e químicas do solo desempenham um papel fundamental no crescimento e rendimento da vinha. Os solos do Sul do Uruguai apresentam um elevado teor de montmorilonite ou illite. As proporções destes minerais merecem especial atenção, uma vez que influenciam a estrutura do solo e as propriedades hídricas. O presente estudo foi realizado numa vinha de 1,1 ha desta região caracterizada por uma elevada heterogeneidade de vigor vegetal. O seu objetivo era determinar e mapear as propriedades físicas e químicas do solo e as suas relações com o vigor e rendimento das plantas. A capacidade de troca catiônica (CEC) e os teores de argila e matéria orgânica foram medidos em 84 locais dentro desta vinha para calcular os teores de montmorilonite e illite do solo. Além disso, o tipo e abundância de argilas foram corroborados pela análise difractométrica de raios X. Os teores de CEC e montmorillonite foram positivamente correlacionados com a vigor da vinha, expresso pelo Índice de Vegetação Normalizada (NDVI), diâmetro do tronco, peso da poda, área foliar, e com o rendimento. Assim, a distribuição dentro da vinha da razão montmorilonite/ilite condicionou a heterogeneidade do crescimento da vinha e o rendimento ao nível do campo. O impacto desses mineraisminerais na água e no fornecimento de minerais à planta é discutido

How soil and climate variability within a vineyard can affect the heterogeneity of grapevine vigour and production

This study aimed to determine how within-plot soil heterogeneity combined with yearly climate variability can promote the heterogeneity of vine growth at plot level, and which soil-climate parameters influence final yield and berry composition the most. An 8-year experiment was conducted on grapevine in two zones of a vineyard (1 ha) differentiated according to grapevine vigour as determined by NDVI: high vigour (HV) and low vigour (LV). The heterogeneity of the soil properties (depth, texture and composition), plant growth (shoots and roots) and plant production (yield components and berry composition) were determined at plot level. Compared to the LV zone, the HV zone was associated with deeper soils, higher soil water and nitrogen availability, CEC and montmorillonite/illite ratio. More extended root systems, higher vegetative growth and higher yield were observed in the HV zone compared to the LV zone. Drier and warmer vintages increased the difference in heterogeneity of vine growth and yield between the two zones. Berry composition (primary and secondary metabolites) also differed between HV and LV zones but seemed unconnected to vigour and mainly depended on soil-climate-plant interactions over the years. The heterogeneity of plant vigour within the vineyard mainly resulted from differences in root exploration, soil profile and composition (notably montmorillonite/illite ratio). The present study identified soil and crop factors that, depending on weather conditions, can be drivers for reducing the heterogeneity of plant development and improving productivity at vineyard level

Montmorillonite content is an influential soil parameter of grapevine development and yield in South Uruguay

International audienceSoil physical and chemical characteristics play a key role on vine growth and yield. The soils of South Uruguay display high content of montmorillonite or illite. The proportion of these minerals deserves special attention as they influence the soil structure and its hydrological properties. The present study was conducted in a 1.1 ha vineyard of this region (Canelones), characterized by a high heterogeneity of plant vigour. It was aimed to determine and map the physical and chemical properties of the soil and their relations with plant vigour and yield. The cation exchange capacity (CEC) and the clay and organic matter contents were measured in 84 locations within this vineyard to calculate the montmorillonite and illite contents of the soil. In addition, the type and abundance of clays was corroborated by X-ray diffractometry analysis. The CEC and montmorillonite contents were positively correlated with vine vigour, expressed by the Normalized Vegetation Index (NDVI), trunk diameter, pruning weight, leaf area, and with yield. Thus, the within vineyard distribution of the ratio montmorillonite/illite conditioned the heterogeneity of vine growth and yield at the field level. The impact of those minerals on water and mineral supply to the plant is discussed.Las características físicas y químicas del suelo desempeñan un papel fundamental en el crecimiento y el rendimiento de la vid. Los suelos del sur de Uruguay presentan un alto contenido de montmorillonita o illita. Las proporciones de estos minerales merecen especial atención ya que influyen en la estructura del suelo y en sus propiedades hídricas. El presente estudio se realizó en un viñedo de 1,1 ha de esta región (Canelones), caracterizado por una alta heterogeneidad de vigor de las plantas. El objetivo fue determinar y cartografiar las propiedades físicas y químicas del suelo, y su relación con el vigor de las plantas y el rendimiento. La capacidad de intercambio catiónico (CEC) y los contenidos de arcilla y materia orgánica se midieron en 84 lugares de este viñedo para calcular los contenidos de montmorillonita e illita del suelo. Además, se corroboró el tipo y la abundancia de arcillas mediante análisis de difractometría de rayos X. Los contenidos de CEC y de montmorillonita se correlacionaron positivamente con el vigor de la vid, expresado por el índice de vegetación normalizado (NDVI), el diámetro del tronco, el peso de la poda, el área foliar y con el rendimiento. Así, la distribución dentro del viñedo de la relación montmorillonita/ilita condicionó la heterogeneidad del crecimiento de la vid y del rendimiento a nivel de campo. Se discute el impacto de estos minerales en el suministro de agua y minerales a la planta.As características físicas e químicas do solo desempenham um papel fundamental no crescimento e rendimento da vinha. Os solos do Sul do Uruguai apresentam um elevado teor de montmorilonite ou illite. As proporções destes minerais merecem especial atenção, uma vez que influenciam a estrutura do solo e as propriedades hídricas. O presente estudo foi realizado numa vinha de 1,1 ha desta região caracterizada por uma elevada heterogeneidade de vigor vegetal. O seu objetivo era determinar e mapear as propriedades físicas e químicas do solo e as suas relações com o vigor e rendimento das plantas. A capacidade de troca catiônica (CEC) e os teores de argila e matéria orgânica foram medidos em 84 locais dentro desta vinha para calcular os teores de montmorilonite e illite do solo. Além disso, o tipo e abundância de argilas foram corroborados pela análise difractométrica de raios X. Os teores de CEC e montmorillonite foram positivamente correlacionados com a vigor da vinha, expresso pelo Índice de Vegetação Normalizada (NDVI), diâmetro do tronco, peso da poda, área foliar, e com o rendimento. Assim, a distribuição dentro da vinha da razão montmorilonite/ilite condicionou a heterogeneidade do crescimento da vinha e o rendimento ao nível do campo. O impacto desses mineraisminerais na água e no fornecimento de minerais à planta é discutido

Montmorillonite content is an influential soil parameter of grapevine development and yield in South Uruguay

Soil physical and chemical characteristics play a key role on vine growth and yield. The soils of South Uruguay display high content of montmorillonite or illite. The proportion of these minerals deserves special attention as they influence the soil structure and its hydrological properties. The present study was conducted in a 1.1 ha vineyard of this region (Canelones), characterized by a high heterogeneity of plant vigour. It was aimed to determine and map the physical and chemical properties of the soil and their relations with plant vigour and yield. The cation exchange capacity (CEC) and the clay and organic matter contents were measured in 84 locations within this vineyard to calculate the montmorillonite and illite contents of the soil. In addition, the type and abundance of clays was corroborated by X-ray diffractometry analysis. The CEC and montmorillonite contents were positively correlated with vine vigour, expressed by the Normalized Vegetation Index (NDVI), trunk diameter, pruning weight, leaf area, and with yield. Thus, the within vineyard distribution of the ratio montmorillonite/illite conditioned the heterogeneity of vine growth and yield at the field level. The impact of those minerals on water and mineral supply to the plant is discussed

Evaluation of site-specific management to optimise <i>Vitis vinifera</i> L. (cv. Tannat) production in a vineyard with high heterogeneity

International audienceThe spatial variability of vineyards can be characterised through precision viticulture that will allow setting the boundaries of homogeneous management zones. This study aimed to evaluate the impact of soil and plant management (site-specific management) to increase yields and improve berry quality. During three consecutive seasons, contrasting treatments designed ad hoc for two zones of vigour pre-established by NDVI were tested: high vigour zone (HV) and low vigour zone (LV). The treatments were aimed at reducing water and nitrogen supply and improving microclimatic conditions in the cluster zone in the HV zone. In the LV zone, treatments were aimed at increasing water and nitrogen supply. Leaf removal in the HV zone was the most efficient treatment to improve productivity and quality. Moreover, the water restriction improved grape quality, especially in a rainy year. The regulated deficit irrigation strategy applied in the LV zone at specific phenological stages was shown to increase vegetative growth, yield and to improve grape anthocyanins and phenols contents. The benefits of additional nitrogen supply in the LV zone on plant nitrogen status, yield, and berry composition were highly dependent on water availability. Ultimately, this study provided new insights into the relationship between water and nitrogen availability and how this determines vigour and influences yield and grape quality and influences the deviation from a “Productive Target” pattern. The use of site-specific techniques could be adjusted on a small production scale, thanks to mapping carried out with precision viticulture technologies

L'effet supergranule d'uree (SGU) en sols de rizieres : probleme de diffusion avec echange d'ions, essai de modelisation

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Genetic structure and mating system of wild cowpea populations in West Africa

Abstract Background Cowpea is a highly inbred crop. It is part of a crop-weed complex, whose origin and dynamics is unknown, which is distributed across the African continent. This study examined outcrossing rates and genetic structures in 35 wild cowpea (Vigna unguiculata ssp. unguiculata var. spontanea) populations from West Africa, using 21 isozyme loci, 9 of them showing polymorphism. Results Outcrossing rates ranged from 1% to 9.5% (mean 3.4%), which classifies the wild cowpea breeding system as primarily selfing, though rare outcrossing events were detected in each population studied. Furthermore, the analyses of both the genetic structure of populations and the relationships between the wild and domesticated groups suggest possibilities of gene flow that are corroborated by field observations. Conclusions As expected in a predominantly inbred breeding system, wild cowpea shows high levels of genetic differentiation and low levels of genetic diversity within populations. Gene flow from domesticated to wild cowpea does occur, although the lack of strong genetic swamping and modified seed morphology in the wild populations suggest that these introgressions should be rare.</p

Systeme d'aide a l'exploitation d'une flotte de transport

SIGLEAvailable at INIST (FR), Document Supply Service, under shelf-number : RP 13830 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc