Wine Shield: Sunscreen for Sauvignon Blanc

Sunburn in grapes is a physiological disorder caused by excessive light radiation and high temperatures. Other stress factors such as water scarcity can exacerbate the problem. Sunburn manifests as brown spots on berry skins, significantly impacting the quality and value of the grapes.

Influential vineyard practices such as canopy management and irrigation techniques affect the sun exposure of grapes, hence the risk of sunburn. Recently, innovative measures against sunburn have been researched and implemented, including the use of protective nets and anti-transpirants.

A standout solution is Kaolin, a chemically neutral aluminosilicate that reflects UV and IR radiation. Applying Kaolin to the crops can reduce the temperature around the berries and affect the photosynthesis rate. Its effectiveness has been tested on various fruits.

Research on Kaolin: Two research projects investigated the impact of Kaolin on Sauvignon Blanc vines regarding their physiology and yields.

From Uruguay: A study found that applying Kaolin from veraison on defoliated Sauvignon Blanc vines yielded the following:

• A reduction in berry surface temperature by 7.2 °C compared to untreated vines.
• The incidence of sunburn decreased by more than 50%.

From Italy: A study in northeastern Italy demonstrated that Kaolin increased yields and acidity levels in the berries.

Conclusion: Kaolin can reduce sunburn while stabilizing vital components like acidity. Its application may help adapt vineyards to the impact of climate change and additionally minimize damage.