First evaluation of the influence of leaf removal on the vegetative and reproductive characteristics of grapevine cv. Nero d’Avola (Vitis vinifera L.) grown under semi-arid conditions

Abstract

Among vineyard management techniques, leaf removal allows modifying the vegetative characteristics of the vines and the micro-climate of the grape clusters. The effects are manifested through a change in the source-sink relationships and in the greater exposure of grape clusters to radiative and thermal conditions, especially in environments with high solar radiation availability. The present study aims to evaluate leaf removal effects on the dynamics of herbaceous growth of clusters and on the technological, phenolic and aromatic quality of the grapes. The study also, investigated the effects of leaf removal on source-sink relationships and in particular on the modifications induced on the dynamics of shoots and leaf surface growth. The study was conducted in 2012 in an experimental vineyard in western Sicily planted with cv Nero D’Avola (Vitis vinifera L.) under dry cultivation. The study revealed that leaf removal in the cluster zone performed post fruit-set modified the vegetative growth of vines, increasing growth dynamics of the shoots and the sink role of the shoot apex. The effects of this agronomic practice were also manisfested in vine productivity by reducing the average berry weight and by inducing modifications in the sugar and acidic content, and in grape phenolic maturity, with an increase in polyphenol content, at least at the early stages of grape ripening and anthocyanin formation.