Kaolin foliar-application improves the photosynthetic performance and fruit quality of Verdejo grapevines

Departamento de Producción Vegetal y Recursos Forestales. ETS de Ingenierías Agrarias. Universidad de Valladolid, Avda. de Madrid, 57, 34004 Palencia, Spain

^* Corresponding author: pedro.martin.pena@uva.es

Abstract

Currently there is an urgent need to adapt vineyards to climate change in order to maintain and improve the quality of wines. In this context, it has been shown that the creation of a film of mineral particles, such as kaolin, on the vegetation can reduce stress caused by high temperatures in plants. The present study evaluated the effects of kaolin foliar-applications, from fruit set to veraison, on the physiological and agronomic behavior of a Verdejo white variety vineyard located in DOP Rueda (Spain). Compared to the controls, treated plants showed an increase in the photosynthetic performance, registering higher values of chlorophyll fluorescence parameters such as Fv/Fm, ΦPSII and ETR, and lower values of F0. Without affecting vigor and yield, grapes from treated vines produced musts with lower pH and phenolic content and greater color luminosity than those of untreated vines. The presented results suggest that kaolin treatments could be an effective tool to minimize the negative effects of climate change on the quality potential of white grape varieties grown in continental areas.