terclim by ICS banner
IVES 9 IVES Conference Series 9 Techniques for sunburn reduction in bunches in Vitis vinifera L. cv. Graciano

Techniques for sunburn reduction in bunches in Vitis vinifera L. cv. Graciano

Abstract

Sunburn results from a combination of excessive photosynthetically active radiation (PAR) and UV radiation and temperature that can be exacerbated by other stress factors such as water deficit. Sunburn is a physiological disorder that affects the visual and organoleptic properties of grapes. The appearance of brown and necrotic spots severely affects the commercial value of the fruit, and in extreme cases, significantly decreases yield.  This damage occurs with some frequency in sensitive varieties such as Graciano. In order to mitigate these impacts, a shading technique has been proposed using protection nets that try to prevent the bunches from receiving excessive sun exposure. The experience shown in this work has been carried out during the years 2021 and 2022, using nets with shading capacity of 50% and 70%, and in 2023 using nets with 25% and 50% with shading capacity. The results have shown that the nets have significantly reduced the temperature of the bunch, also avoiding damage from sunburn. Besides, the organic acid content of the must has reached slightly higher values in the treatments with netting, compared to the control, but not significantly. In wine, the polyphenolic load has shown a variable behavior depending on the year, possibly conditioned by the variations in yield linked to the sunburn. The tasting panel has shown a certain inclination towards the wines from the net treatments.

DOI:

Publication date: June 14, 2024

Issue: Open GPB 2024

Type: Poster

Authors

Luis Rivacoba*, Javier Portu, Sergio Ibáñez

Instituto de Ciencias de la Vid y del Vino (Gobierno de La Rioja, Universidad de La Rioja, CSIC). Finca La Grajera, Ctra. de Burgos Km. 6, Logroño, La Rioja 26007, Spain

Contact the author*

Keywords

sunburn, shading, Graciano

Tags

IVES Conference Series | Open GPB | Open GPB 2024

Citation

Related articles…

Characteristics of ecological production of grape and wine in Prizren’s vineyard territory in Yugoslavia

Prizren’s vineyard territory-y assigned for ecological production of grapes and wine includes 1. 200 hectares of vineyard located in five separate localities which belongs to the P KB “Kosovo vina”, Mala Krusa in Prizren. Division of vineyard territory in zones was carried out in 1974. Pertaining to the vineyards, the climate and soil conditions have been studied and determined as well as topographie establishing of vineyard boundaries.

Evaluation des aptitudes œnologiques des raisins rouges avec l’étude de certains nouveaux indices de maturité phénolique

Pour obtenir des vins d’une certaine gamme, il faut connaître les paramètres liés à la composition de la baie et introduire non seulement les paramètres classiques, c’est-à-dire sucres et acidité, mais aussi les paramètres qui tiennent compte

POTENTIAL OF PEPTIDASES FOR AVOIDING PROTEIN HAZES IN MUST AND WINE

Haze formation in wine during transportation and storage is an important issue for winemakers, since turbid wines are unacceptable for sale. Such haze often results from aggregation of unstable grape proteinaceous colloids. To date, foreseeably unstable wines need to be treated with bentonite to remove these, while excessive quantities, which are often required, affect the wine volume and quality (Cosme et al. 2020). One solution to avoid these drawbacks might be the use of peptidases. Marangon et al. (2012) reported that Aspergillopepsins I and II were able to hydrolyse the respective haze-relevant proteins in combination with a flash pasteurisation. In 2021, the OIV approved this enzymatic treatment for wine stabilisation (OIV-OENO 541A and 541B).

Chitosan treatment to manage grapevine downy mildew

Downy mildew is one of the most important grapevine diseases, caused by the Oomycete Plasmopara viticola. The management of the disease in organic agriculture can require up to 15 copper applications per year. However, copper accumulates in the soil, is phytotoxic and is toxic for organisms living in the soil, its use has been restricted in European Union to maximum 28 kg in 7 years. Therefore, testing of alternatives with equal effectiveness is desirable. Among those, the natural biopolymer chitosan, obtained from crab shells, proved to be effective toward downy mildew in plot experiments. The aim of our trials was to extend chitosan applications in large scale experiments in different years, cultivars and environmental conditions.

Understanding and managing wine production from different terroirs

A « terroir » is a cultivated ecosystem in which the vine interacts with the soil and the climate. Main climatic parameters include temperature, rainfall and reference evapotranspiration