Climate change: Kaolin applications appear to reduce the negative effects of high temperatures and heat stress on canopy physiological processes, yield and fruit quality. The kaolin coating works by significantly reducing leaf temperatures in comparison to untreated vines, with an average of about − 4 °C and up to −6 °C. Moreover, it maintains high the photosynthetic activity preventing irreversible photoinhibition phenomena, whereas untreated vines exhibit a marked physiological damage with chlorotic and necrotic leaves, dehydrated berries and sunburn damages. At harvest, 30-35% of the untreated vines were affected by severe water stress symptoms and produced unmarketable fruits. In comparison to the untreated vines, those sprayed with kaolin showed a higher yield (+27%), higher anthocyanins (+35%) and higher concentration of organic acids (+11%).

Source: Kaolin treatments on Pinot noir grapevines for the control of heat stress damages. BIO Web Conf. Volume 13, 2019, CO.NA.VI. 2018 – 7° Convegno Nazionale di Viticoltura

Tommaso Frioni1, Sergio Tombesi1, Elisa Luciani2, Paolo Sabbatini3, Julian G. Berrios4 and Alberto Palliotti2*

1 Dipartimento di Produzioni Vegetali Sostenibili, Università Cattolica del Sacro Cuore, Via E. Parmense 84, 29121 Piacenza, Italy
2 Dipartimento di Scienze Agrarie, Alimentari e Ambientali, Università di Perugia, Borgo XX Giugno 74, 06121 Perugia, Italy
3 Department of Horticulture, 1066 Bogue Street, East Lansing, Michigan State University, USA
4 Departamento de Produccion Vexetal, Universidad de Santiago de Compostela, Escola Politecnica Superior, Campus Universitario− E-27002 Lugo, Spain