Manipulation of ripening via antitranspirants in cv. Barbera (Vitis vinifera L.)

Abstract

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.

Post‐veraison trimming slow down sugar accumulation without modifying phenolic ripening in Sangiovese vines

“…Several authors have previously shown that the reduction of leaves with high photosynthetic activity immediately after veraison has no influence on the concentration of anthocyanins and tannins in berries and our results at harvest during the three years confirm these findings. A recent work reported that the strong reduction in leaf‐to‐fruit ratio (from 1.15 to 0.33 m 2 kg −1 caused by the removal of 80% of leaf area) at veraison resulted in a decrease in soluble solid accumulation associated with a significant reduction in secondary metabolites, such as anthocyanins, without substantial differences in their composition.…”

“…Different vineyard strategies are now available to slow down sugar accumulation and decelerate overly quick and unbalanced berry ripening . The most effective of these are based the limitation of substrate availability during ripening through post‐veraison leaf removal of the upper part of the shoots .…”

“…Different vineyard strategies are now available to slow down sugar accumulation and decelerate overly quick and unbalanced berry ripening. [32][33][34][35][36] The most effective of these are based on the limitation of substrate availability during ripening through post-veraison leaf removal of the upper part of the shoots. 37,38 The physiological background is that, around veraison, leaves located on the apical part of the canopy are the most functional and are still able to elaborate carbohydrates.…”

A multivariate approach for the ampelographic discrimination of grapevine (Vitis vinifera) cultivars: application to local Syrian genetic resources

“…In this sense, berry traits like weight (BE_We), length (BE_Le), figure online) width (BE_Wi), elongation (BE_E) and shape (BE_SH) were highly correlated, and so happened with some cluster traits like length (CL_L), width (CL_Wi), elongation (CL_E), volume (CL_TV) and weight (CL_We). As observed in different grapevine cultivars (Gatti et al 2016;Ivorra et al 2015), the objective compactness index CI-12 proposed by Tello and Ibáñez (2014) correlated significantly with the visual OIV rating in our sample, supporting the usefulness of this indicator for the quantitative estimation of this trait. Interestingly, seed number (BE_SB) did not correlate significantly with berry dimension variables (BE_We, BE_Wi) or its value of significant correlation was low (BE_Le).…”

What do we know about grapevine bunch compactness? A state-of-the-art review

“…Leaf photosynthetic activity can be also interrupted by alternative and innovative systems, including the use of leaf anti‐transpirants and artificial shading. Oily substances used as leaf anti‐transpirants, such as paraffin and pinus oils, occlude the stomata of leaves, hinder their transpiration and influence carbon dioxide absorption, which ultimately hamper the photosynthetic activity of leaves (Palliotti et al , Hanni et al , Gatti et al ). Their application at pre‐flowering and full‐flowering reduces the mobilisation of carbohydrates to developing inflorescences, which promotes flower drop and reduces berry number and bunch compactness (Table ).…”