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Selection of new grape cultivars by intraspecific crossing increases biodiversity as well as improves some parents’ characteristics. However, their success is still unclear. It seems to depend upon how well they respond to different challenges and demands of the modern viticulture, such as their adaptability to climate change and vineyard mechanization. This research aims to characterize vine performance and suitability to mechanical harvesting of cultivar ‘Ervi’ (V. vinifera L.), an Italian crossbreed between ‘Barbera’ and ‘Croatina’. The trial was performed between 2008 and 2010 on the Piacenza hills using Guyot trained vines. Cluster number and yield per vine were recorded at harvest. Subsequently, shoot fertility, cluster and berry weight were calculated accordingly. Soluble solids, pH and must titratable acidity were analyzed as well as total anthocyanins and phenols grape content. A pool of 891 berries was randomly picked and their respective detachment force was measured by a dynamometer. ‘Ervi’ showed more constant yield than its parents and shoot fertility higher than ‘Croatina’ suggesting that short spur pruning is feasible. Berry weight in ‘Ervi’ was also lower than in ‘Barbera’. Ripening was earlier than both parents. The adaptability of ‘Ervi’ to the mechanical harvesting is similar to ‘Barbera’ and better than ‘Croatina’. The BDF is cultivar-dependent and is an important parameter for mechanical harvesting. Its application as a maturity index is still premature.

Cost-effective yield management is becoming fundamental in modern viticulture in order to meet the existing yield regulations in many parts of the world and to improve grape quality. The evaluation of mechanically performed early defoliation and crop thinning, aiming at yield management, and their effects on the vegetative growth, yield components, grape and wine composition, against a non-defoliated, not-thinned control, and manual treatments are presented. Manual and mechanical early defoliation and crop thinning were conducted at pre-bloom and veraison, respectively, on ‘Tempranillo’ (Vitis vinifera L.) VSP grapevines in season 2009. A detailed description of the mechanical settings and adjustments, based on preliminary results from previous seasons, for the correct performance of both techniques is provided. Whilst total leaf area remained unaltered, yield was drastically reduced by both practices (38-40%), hence the leaf-to-fruit ratio also enhanced with respect to control vines. Cluster weight, berry number, as well as cluster compactness and Botrytis incidence were also reduced in yield regulated vines, but berry weight tended to increase in mechanically thinned vines and remained unaffected in the early defoliated plants. Berry soluble solids, anthocyanins and total phenols, as well as wine alcohol, color density and total phenol index were generally higher in mechanically early defoliated vines. Effective yield control and fruit quality improvement in VSP grapevines may be accomplished mechanically.

The responses to late season mechanical leaf removal (four weeks after verasion) conducted above the clusters zone in ‘Sangiovese’/3309 C vines trained to spur-pruned cordon were assessed in 2011 as grape composition, wine quality and replenishment of the reserve in roots and stems. Eliminating 36% of the more functional leaves (i.e. median leaves and a fraction of well-expanded apical leaves of either primary and lateral shoots) resulted an effective, easy-to-do and economically viable method (it required only 3-4 hours per hectare) to slow grape ripening and obtain grapes with reduced soluble solids concentration and wine with lower alcohol content (-0.6%). Concurrently, the concentration of phenolics compounds in the grapes, the chemical and chromatic characteristics of the wines and the replenishment of the reserves (alcohol-soluble sugars, starch and total nitrogen) in the stems and roots were unaffected as compared to the non defoliated vines. This preliminary data also suggest that, in ‘Sangiovese’, a robust response can be achieved if leaf removal is performed when the soluble solids concentration in the berries ranges around 15-16 °Brix and while severity of defoliation should not be less than 35-40% of the pending total leaf area.

Deficit irrigation may be used to control canopy development, yield, and fruit composition in order to enhance fruit colour, texture, and juice composition. The present study was carried out in 2007 using five-year old Lambrusco grapevines grown with the root system split into two pots. Water stress was applied on half of the vines (stressed) by withholding water from one out of the two pots from pre-veraison till harvest. At harvest, yield and cluster number per vine were recorded. Leaves and berries were collected and their mineral composition analyzed. Samples of 200-berries were collected to obtain qualitative parameters and to investigate mechanical properties using a TAxT2i Texture Analyzer. In order to confirm berry skin values obtained using texture analysis, microscope observations were made on frozen samples. Berry development (cluster and berry weight) was reduced by water stress; yield, sugar concentration, acidity and pH were similar between treatments, while malic acid and potassium concentrations in control vines were greater than in stressed vines. Water stress significantly enhanced the total anthocyanins. Mechanical properties of berries were strongly affected by water stress, showing a significant increase of berry skin thickness and a decrease of firmness. Microscope observations confirmed greater skin thickness as a result of water stress. Calcium, Mg, and B content in leaves and in berries significantly changed when water stress conditions were imposed. Sulphur and Mn content in leaves and P content in berries were also affected by treatment. These changes probably resulted from differential uptake and flow of nutrients from leaves to berries under water stress. In particular low Ca in leaves and high Ca levels in berries were registered in stressed vines, indicating the important role of Ca in enhancing berry skin thickness. The same pattern of flow from leaves to berries was noticed for Mg. In contrast, low levels of B were found both in leav

The effects of early season leaf removal on 'Barbera' and 'Trebbiano' cluster morphology and grape quality were examined under potted and field conditions. Potted, non-defoliated 'Barbera' vines (A) were compared to treatments in which the basal portion of the shoot (nodes 1 to 8) was defoliated at a 50 or 100% level pre-anthesis (B, C), post-anthesis (D, E) or 50% both times (F). Treatments A, C, E and F were also replicated in the field using 'Barbera' and 'Trebbiano' grapevines. Fruit-set was reduced by all treatments resulting in looser clusters than the control. The minimum and maximum reduction in cluster weight was 29 and 48% for treatments B and F, respectively, in the pot study. It was 47 and 69% for treatments F and C, respectively, in the field for 'Barbera' and 44 and 56% for treatments F and C, respectively, for 'Trebbiano'. In all cases cluster size reduction was due to reduced berry number rather than smaller berry size. Sugar concentration increased for all defoliation treatments as a result of lower yield per shoot and leaf area to fruit weight ratios (shoot basis) either similar or higher than those of controls. The amount of sugar produced per unit leaf area (shoot efficiency) did not differ significantly among treatments in the potted study or for 'Trebbiano' in the field. Shoot efficiency was reduced in the C treatment for 'Barbera' in the field. These data demonstrate the potential of early season leaf removal for crop control and improvement of fruit characteristics at medium-to-high vigor sites. Work in progress will evaluate carry-over effects and feasibility of mechanical leaf removal in the vineyard.

This paper reviews methods available for assessing the efficiency of a grapevine canopy which, due to the flexible canes characterizing this species, can be trained to a multitude of geometrical forms. "Efficiency" is defined here as the ability to share high light interception with effective light distribution within the canopy while reaching concurrently adequate dry matter partitioning to clusters and renewal wood. A traditional approach to the canopy efficiency issue is the calculation of well known vine balance indices (i.e. yield-to-pruning weight or leaf area-to-yield ratios) which are indeed useful to highlight deviations from "equilibrium" but are also static (usually calculated at harvest) and often poorly correlated with "source" potential and grape quality parameters. Total amount and "quality" of intercepted light obtained through canopy laser scanning approaches are promising parameters in terms of correlation with actual whole-canopy photosynthesis (at least for canopy of low-to-moderate vigour) and assessment of training systems as related to light exposure of different organs depending upon their age and position. Yet, these methods are quite time consuming and hardly applicable on a large scale. Over the last decade an increasing popularity has been gained by the treeenclosure method consisting in measuring the gas exchange of entire canopies enclosed in "balloons" made of polyethylene or other plastic material. This method overcomes the inherent limitations of single-leaf measurements and provides valuable information as related to the incidence of factors such as shading, ageing, leaf healthiness at the whole canopy level as well as effects due to different summer pruning operations. Weaknesses are that no commercial versions of these systems are still available and that maximum care is needed to assure that the micro-environment inside the chambers is reproducing as close as possible the outside environment. The last frontier in assessment of gr