Feeling the heat? Keep cool this summer with OmyaPro Sun

Everyone’s talking about climate change and the impact it’s having on global agriculture. But when you’re enjoying a glass of wine this summer, spare a thought for those growers responsible for vineyards across the world. Increasing temperatures mean grape harvests have advanced by 2 – 3 weeks over the past 40 years, with alterations in grape composition at harvest having an impact on wine quality and style (van Leeuwen, C., Sgubin, G., Bois, B. et al, 2024). Wine-growers need to adapt their strategies to deal with hotter summers and to protect their crops against both heat stress and sunburn, or risk being unable to continue wine production in some regions long term. 

Katharina Kötting , Director Innovation & Technical Marketing Agriculture for Omya, offers a solution. “It is important to protect the vines from heat and sunburn, without affecting their ability to photosynthesise. Across Europe, vineyards are having success in reducing leaf and fruit temperatures with our natural biostimulant, OmyaPro Sun.  It’s a wettable powder that is sprayed on the crops before the temperature rises, forming a protective film that reflects the sunlight. Plants can continue photosynthesis during the heat of the day, improving crop growth and fruit development.” 

OmyaPro Sun is made from natural calcium carbonate, which is micronized into fine powder. When mixed with water it can be sprayed onto vines using standard spray equipment. The resulting film is rain-resistant and is proven in trials to maintain a cooler temperature in both leaves and grapes when compared with either untreated or kaolin-treated wines. This reduces heat stress on the crop and can result in water savings for the grower. 

As Ms Koetting explains, “Managing heat in the leaves and fruit has a huge impact on grape production. If growers can reduce leaf and fruit heat by around 5 degrees at midday, it significantly increases both yield and quality.  In trials over two years, vines treated with OmyaPro Sun produced grapes with average weights 45% higher than untreated vines and 22% higher than kaolin-treated vines. We recommend applying OmyaPro Sun as soon as the temperature reaches 30°C degrees, as that is when heat stress will begin to have an effect on growth.” 

Another benefit of OmyaPro Sun is that it provides calcium nutrition to the crop. Calcium is essential for cell strength and promotes grape firmness, an important parameter of quality both in the field and at harvest. Firm skin reduces the risk of damage and pathogen infection, as well as ensuring the grapes remain intact, avoiding the production of must which would oxidise before processing. OmyaPro Sun protects yield, quality and storability, resulting in greater profitability for the grower. 

Ms Koetting concludes, “as global temperatures continue to rise, some wine-growing regions may find it much more difficult not only to achieve expected yields but, more importantly, to maintain quality. Bringing down the temperature of the leaves and fruit on the vine will not only help maintain yields but also enable grape production to continue for longer, while keeping the balance between sugar, acidity, and tannins for good wine production.” 

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