Foliar application of kaolin and zeolites to adapt the adverse effects of climate change in Vitis vinifera L. cv. Sangiovese

Abstract

One of the first effects of climate change in wine-growing areas is the advancement of phenological stages, especially concerning early berry ripening. In this condition, the decoupling between technological and phenolic maturity often occurs. Anthocyanins in red grapes are among the compounds that mostly contribute to phenolic maturity. However, their accumulation in the grape berries is known to be impaired by high temperatures. Therefore, this study aims to evaluate the efficacy of mineral-based compounds treatments with kaolin and zeolite, based on chabasite, on the enhancement of anthocyanins accumulation, also at the molecular level, analysing the gene expressions along the flavonoid biosynthesis pathway during ripening of Sangiovese berries. In addition, the temperature of berries and grape leaves, vine water status, leaf photosynthetic efficiency, total soluble solids, titratable acidity and pH were measured throughout the growing season. Hence, in the current study, it has been demonstrated the efficacy of kaolin and zeolite treatments not only in lowering the daily maximum grape berries temperature but also in the improvement of grapes anthocyanins accumulation correlated with the enhancement of expression of those genes involved in their biosynthesis pathway. Moreover, treatments had no significant effect on productive parameters.