Spatial information on vineyard soil properties can be useful in precision viticulture. In this paper a combination of high resolution soil spatial information of soil electrical resistivity (ER) and ancillary topographic attributes, such as elevation and slope, were integrated to assess the spatial variability patterns of vegetative growth and yield of a commercial vineyard (Vitis vinifera L. cv. Tempranillo) located in the wine-producing region of La Rioja, Spain. High resolution continuous geoelectrical mapping was accomplished by an Automatic Resistivity Profiler (ARP) on-the-go sensor with an on-board GPS system; rolling electrodes enabled ER to be measured for a depth of investigation approximately up to 0.5, 1 and 2 m. Regression analysis and cluster analysis algorithm were used to jointly process soil resistivity data, landscape attributes and grapevine variables. ER showed a structured variability that matched well with trunk circumference spatial pattern and yield. Based on resistivity and a simple terrain attribute uniform management units were delineated. Once a spatial relationship to target variables is found, the integration of point measurement with continuous soil resistivity mapping is a useful technique to identify within-plots areas of vineyard with similar status.

Aim: To test the hypothesis that shading of the fruiting zone of the plants might reduce yield losses caused by excessive exposure to sun while avoiding the most damaging effects associated with reduced radiation.Methods and results: A number of grapevine rows were shaded with a double layered white plastic netting on their south-facing side, from the ground to about 20 cm above the cluster zone. Data on meteorological conditions, plant growth, plant water availability, yield components and must characteristics were recorded during three growing seasons. Shading significantly increased yield but did not alter significantly the must characteristics.Conclusion: Partial shading of the grapevine canopy reduced yield losses attributable to excessive radiation. The must obtained from shaded berries had a lower concentration of anthocyanins, and the wines made from these musts had a lighter colour which may be detrimental to their quality.Significance and impact of the study: The study highlights the effects of solar radiation on the composition of grape musts and suggests a potentially cost-effective method to control excessive radiation in vineyards.

In regions with Mediterranean climate, water is the major environmental resource that limits growth and production of plants, experiencing a long period of water scarcity during summer. Despite the fact that most plants developed morphological, anatomical, physiological, and biochemical mechanisms that allow to cope with such environments, these harsh summer conditions reduce growth, yield, and fruit quality. Irrigation is implemented to overcome such effects. Conditions of mild water deficit imposed by deficit irrigation strategies, with minimal effects on yield, are particularly suitable for such regions. Efficient irrigation strategies and scheduling techniques require the quantification of crop water requirements but also the identification of pertinent water stress indicators and their threshold. This chapter reviews the scientific information about deficit irrigation recommendations and thresholds concerning water stress indicators on peach trees, olive trees, and grapevines, as case studies.