Background and Aims The increasing interest by the wine market in sparkling white wines challenges how the desired grape composition can be achieved under the pressure of global warming. The aim of the present study was to assess the viability of summer pruning as a tool to pilot ripening towards desired compositional patterns. Methods and Results Ortrugo was subjected to basal leaf removal applied either at pre‐flowering (ELR) or in lag‐phase (LLR) and to bunch thinning (BT; removal of 50% of crop at lag‐phase) in comparison with untreated control (C). Treatments induced large variation in bunch mass (30% less in ELR vs BT), yield per vine (37 and 21% less in BT and ELR vs C) and total soluble solids at harvest (BT scored 2.9°Brix higher than that of C). Conversely, given the same harvest date, all practices failed to maintain titratable acidity (TA) at the threshold of 6.5 g/L. Conclusions The data suggest that crop regulation achieved in the high yielding Ortrugo, through either BT or ELR, increases sugar accumulation rate so that concurrent optimal TA level (≅6.5 g/L) can be easily achieved by slightly anticipating harvest date. Under conditions of thermal or light stress, or weather conducive to bunch rot, preference should be given to ELR. Significance of the Study Suitable summer pruning techniques might be used as flexible and powerful tools to direct ripening towards the desired crop composition.

Background and Aims Accelerated berry sugar accumulation resulting in wines of excessive alcohol concentration, sub‐optimal colour and atypical flavour has become increasingly frequent in warm growing districts, a trend induced by factors that include global warming. The application of a film‐forming antitranspirant may be an effective way of reducing early sugar accumulation without affecting colour development. Methods and Results An antitranspirant emulsion was applied in 2013 and in 2014 on field‐grown cv. Barbera vines at pre‐flowering (PF), pre‐veraison (PV) and at both dates (PFPV), and compared with the unsprayed control. Post‐treatment assessment included seasonal gas exchange, yield components, growth of berry organs and must composition. Although all treatments were effective in reducing gas exchange by as much as 46% compared with that of the control, berry growth was not affected. Conversely, whereas PF slightly modified the ripening pattern, PV and PFPV markedly delayed accumulation of sugar in the warm 2013 season (−2.4 and −3.7° Brix, respectively, vs control) without detriment to colour development because the onset of anthocyanins occurred at lower TSS. In the cooler, wet 2014 season, PV and PFPV were again able to delay sugar accumulation without affecting colour development. Conclusions Pre‐veraison application of the antitranspirant alone or in combination with a PF spray proved effective in slowing sugar accumulation while avoiding concurrent delay of colour development. Significance of the Study The use of antitranspirants is a practical and flexible way of regulating the sugar : anthocyanin ratio under conditions of excessively fast ripening.

No abstract

No abstract

Global warming is endangering maintenance of optimal grape composition in white varietals aimed at sparkling wine making due to difficulties to maintain adequate acidity and fresh aromas. These troubles are being faced by the main white varietal of the Colli Piacentini district, named Ortrugo. Its vegetative and reproductive behavior was compared over 3 years with that of other minor autochthonous white varietals. Criteria set for adequate grape composition under sparkling vinification (total soluble solids at 20-21 • Brix) and titratable acidity (TA) ≥ 6.5 g/L combined with Principal Component Analysis (PCA) on the measured variables allowed a thinnning down of the initial group of 17 to 7 varietals including Ortrugo,