Potential Use of Kaolin in Viticulture: Physiological Basis and Future Perspectives

Since ancient times, clays have been used to protect plants from insects and excessive sunlight. Today, their potential use is being re-evaluated as a tool to mitigate the effects of climate change and to manage emerging pests. This review synthesizes and compares findings from studies conducted in different regions of the world. Kaolin forms a reflective film on leaves and fruits, lowering tissue temperature. In warm climates, this temperature reduction can contribute to improved physiological parameters including net assimilation and water use efficiency; however, these responses are strongly influenced by additional factors. It may also affect some oenological characteristics of grapes (acidity, pH, and phenol content, particularly anthocyanins), thereby improving the overall chemical composition of grapes and wines, particularly in terms of acidity, pH and phenolic content. In addition, kaolin has been shown to reduce damage caused by the grape leafhopper (Empoasca vitis, Jacobiasca lybica, among others) to levels comparable to those achieved with synthetic pesticides. However, responses vary depending on different factors, such as application timing, dose, cultivar and climate. Overall, kaolin represents a sustainable strategy for mitigating climate change effects on fruit quality and for supporting ecological pest management.