 IVES 9 IVES Conference Series 9 Macrowine 9 Macrowine 2021 9 Grapevine diversity and viticultural practices for sustainable grape growing 9 Effect of application of kaolin and pinolene on grape berry cell death, berry shrinkage, and ethanol accumulation

Effect of application of kaolin and pinolene on grape berry cell death, berry shrinkage, and ethanol accumulation

Abstract

AIM: Cell death in Vitis vinifera L. berries late in ripening and berry shrinkage (loss of mass) can decrease yield and reduce grape quality in cultivars such as Cabernet Sauvignon, Merlot, and especially Shiraz. Techniques to ameliorate effects of cell death and berry shrinkage are limited. Pinolene and kaolin are two types of film-forming antitranspirants applied to plants to reduce water loss. If these antitranspirants create a water impermeable coating, they may also restrict gas exchange, exacerbating hypoxia associated with cell death in grape berries. This study aimed to identify the effects on berry physiology during ripening of kaolin and pinolene coatings on Shiraz and Grenache bunches.

METHODS: Kaolin (6% w/w), pinolene (1% w/w) and water (control) were sprayed on Shiraz and Grenache bunches (2019-2020, Waite campus University of Adelaide) during ripening every 7 to 15 days. Change in berry mass, cell vitality, internal oxygen concentration, ethanol accumulation and bunch and canopy temperature were recorded.

RESULTS: Grenache berries had almost no shrinkage and no cell death during development contrasting to continuous decline in berry mass and cell vitality in Shiraz berries from 85 days after anthesis. Kaolin had no effects on berry properties. Pinolene reduced loss of berry mass in Shiraz and slightly increased berry mass in Grenache, leading to lower sugar concentrations in both cultivars. There was no effect of pinolene on berry oxygen concentration or cell vitality since both declined similarly to controls. There was an exponential increase in berry ethanol concentration with increasing mean daily temperature. Berry ethanol concentration for Grenache was much lower than for Shiraz under similar temperature conditions. There was no effect of treatments on berry ethanol concentrations.

CONCLUSIONS

Pinolene decreased berry shrinkage and prevented high sugar concentration presumably by reducing transpiration without impacting sugar content. It was surprising that this compound could decrease water loss without apparently affecting internal oxygen concentration in the berry. Ethanol accumulation during berry ripening could be a causative factor of cell death or is closely associated with it. Temperature may decrease berry vitality by accelerating respiration which leads to anoxia and high ethanol production.

DOI:

Publication date: September 2, 2021

Issue: Macrowine 2021

Type: Article

Authors

Lishi Cai

School of Agriculture, Food and Wine, The University of Adelaide, PMB1, Glen Osmond, SA 5064, Australia,Apriadi Situmorang School of Agriculture, Food and Wine, The University of Adelaide, PMB1, Glen Osmond, SA 5064, Australia Steve Tyerman School of Agriculture, Food and Wine, The University of Adelaide, PMB1, Glen Osmond, SA 5064, Australia

Contact the author

Keywords

Citation

Unraveling grapevine resilience to water and nutrient limitations

Water and nutrient availability significantly impact crop yield, thus the application of sustainable strategies towards efficient water use and nutrient absorption by plants is needed.

Mechanical fruit zone leaf removal and deficit irrigation practices interact to affect yield and fruit quality of Cabernet Sauvignon grown in a hot climate

Cabernet Sauvignon is the top red wine cultivar in CA, however, the hot climate in Fresno is not ideal for Cabernet Sauvignon, particularly for berry color development. Fruit-zone leaf removal and irrigation were studied previously to have the significant effect on grape yield performance and berry quality. But the timing of leaf removal and the timing of irrigation are still inconclusive. Also, mechanical fruit-zone leaf removal is relatively new in CA. Our study aims to identify the interactive effect of mechanical fruit-zone leaf removal and irrigation on Cabernet Sauvignon’s yield performance and fruit quality and find the ideal timing of leaf removal and irrigation to maximize the berry color while maintaining the sustainable yield level.

Berry maturity effects on physic and chemical characteristics of traditional sparkling wines produced from Chardonnay and Sauvignon blanc grapes.

One of the consequences of global warming is the quick berry development giving rise to a disconnection between sugar accumulation and the formation of important quality minor compounds such as phenolics and volatile compounds being a huge challenge for the oenologist [1]. Thus, this phenomenon is forcing the search on strategies for maintaining the quality of wines despite this situation. One possibility is to make an early harvest with a low sugar concentration (18ºbrix) and advanced harvest for sparkling wine (20-21ºbrix) and afterwards to combine base wines properly and carry out the second fermentation trying to compensate the lack of secondary metabolites due to the quick berry development and higher alcohol degree of the second one, not adequate itself for sparkling wine. The aim of this study was to assess the chemical and physical characteristics, mainly volatile profile, and foaming properties of sparkling wines from grapes of Chardonnay and Sauvignon blanc.

Characterization of commercial enological tannins and its effect on human saliva diffusion

Commercial oenological tannins (TECs) are widely used in the wine industry. TECs are rich in condensed tannins, hydrolyzable tannins or a mixture of both. Wine grapes are a important source of proanthocyanidins or condensed tannins while oak wood possess a high concentration of hydrolyzable tannins (Obreque-Slier et al., 2009). TECs contribute with the antioxidant capacity of wine, catalyze oxide-reduction reactions and participate in the removal of sulfur compounds and metals.

Phenological stage dependency of Cabernet Sauvignon and Grenache response to water and nutrient limitation

As the frequency and intensity of drought events increase, understanding the mechanisms of plant resilience to water deficit is crucial. To maintain an appropriate plant yield, a common practice is the application of high amounts of fertilizers with negative environmental impacts. The single and combined effect of water deficit and nutrient availability, namely nitrogen (N) and potassium (K), in Vitis Vinifera L. cv. Cabernet Sauvignon and Grenache was evaluated. Two-year-old grapevine plants grafted on SO4 rootstock were transferred in pots under semi-environmental conditions. During the growing season, plants were either maintained well-watered (100% ETc) or subjected to a controlled water deficit irrigation (33% ETc).