Volatile Organic Compound markers of Botrytis cinerea infection in artificially inoculated intact grape berries

The grape variety Gewürztraminer is known to be affected by two physiological disorders namely berry shrivel and bunch stem necrosis. During the season 2014 we noticed a new symptomatology type of ripening disorder on the variety. The new symptom showed not all berries fallowing the normal maturation stages, but single berries remaining at a soft but green stage till harvest. The broad distribution of these so called “green berries” symptoms in different production sites of our region, caused huge damage due to the difficulty of eliminating single berries per bunch before harvesting. Therefore, the Research Centre Laimburg began to investigate the reasons and origins of this new symptom. This work shows the results of first attempts to find causes for the symptom as well as the resulting approach to mitigate symptoms. Applications of magnesium leaf fertilizer showed first promising results against this putative disorder. To study the causal effect of the green berries 30 symptomatic vineyards in 2014 have been selected for a monitoring during the season 2016. To evaluate the foliar nutrient treatment two vineyards have been selected for application of magnesium sulfate and magnesium chloride. Leaf and berry nutrient analysis, as well as the main quality parameters during ripening have been performed. As soon as “green berries” symptoms appeared, incidence and severity have been evaluated. Most of the symptomatic vineyards of the 2016 monitoring showed light to clear magnesium deficit symptoms on their foliage. Only during the seasons 2020 and 2021 “green berries” symptoms could be found in the leaf fertilizer treatment vineyards. Both seasons showed a significant effect of the magnesium treatments to reduce the incidence and severity of the symptom. It seems that the appearance of the “green berries” symptom on Gewürztraminer is correlated to a disturbed uptake of magnesium of the vines.

We have sequenced two commercial strains of Lachancea thermotolerans (Lt) from the company Lallemand: Laktia™ y Blizz™.

Cork taint decreases the commercial value of wine as tainted wines are rejected by consumers. Although other compounds in wine and cork can also be responsible for causing a taint, 2,4,6-trichloroanisole (TCA) is regarded as the primary cause of cork taint. As cork taint is often used in marketing campaigns against natural cork closures,

Terroirs represent a heritage that must be studied and managed with appropriate methods; recourse to agronomic and oenological sciences alone is necessary, but is in no way sufficient without the contribution of the humanities.

This report examines product quality assurance issues arising when technological aids and food additives are utilized in winemaking.