Italian Zeolitites in the Control of Grey Mould and Sour Rot and Their Effect on Leaf Reflectance, Grape and Wine

Abstract: The activity of two zeolitites, differing in the presence of copper and their particle size, was assessed in a Trebbiano d’Abruzzo white berry cultivar, towards grapevine grey mould and sour rot, a serious problem in almost all grapevine-growing areas. In 2018 and 2019, zeolitites were applied before forecast of rainfalls, which likely induce infection. In 2019, further applications were carried out 10 or 2 days before harvest, regardless of the rainfall, in order to verify the effect of the zeolitite residue on leaf reflectance and composition of grapes and wines. Both zeolitites significantly reduced the infections. Only the vines treated 2 days before harvest, especially with copper zeolitite, showed a decrease in leaf reflectance. However, no differences in the yield composition related to the time of zeolitite application, as well as a decrease of yield quality, were ever recorded. Furthermore, analysis of samples collected from vines treated with zeolitites showed increases in grape soluble solids and in wine alcohol content. Our results suggest the use of zeolitites against grapevine rots as a possible effective alternative to the application of synthetic fungicides in the development of environmentally friendly control strategies.