Effects of different intensity of early leaf removal on vegetative and productive activity and grape quality (cv. Nero d'Avola, Vitis vinifera)

Mestrado Vinifera Euromaster - Instituto Superior de Agronomia - ULThe trial wants to study the characteristics of c.v. Nero d’Avola in the Eastern part of Sicily after early leaf removal. Axiom to create high quality wine is to have high quality grapes. This can be possible only with right management of vineyard. The objective is to understand how the early leaf removal can change the productive and vegetative balance of vine and micro-climate of the cluster region. Specifically this research wants to highlight the process that some variables can cause during the leaf out process of the cv Nero d’Avola in the area of Hyblaean Mountains (Monti Iblei). This study show like early leaf removal at fruit set stimulates the increase of the length of lateral shoots. The early defoliation influenced the fruit-set processes, in terms of lower berry number and a higher percentage of chicken berries. The sugar content was positively influenced by early defoliation .Probably related to the greater leaf area per gram of grapes at harvest , younger canopy in the last stage of ripening and also for greater exposure of luster to light. The percentage of light interception is higher in the defoliated treatments ,especially, in the south-east side of canopy. About anthocyanin accumulation we can confirm that early defoliation lead to a more rapid build-up, thanks to the exposure to light, which stimulates the metabolites synthesis. Defoliation remains a very effective way to diversify agronomic management and the types of grapes obtainable from a same variety in the same environment. In conclusion we can say ,the defoliation at different times and different intensity, depending on the climate and the environment, can control the yield, especially in high-yielding varieties, and can improve the sugar accumulation, and increase the concentration of polyphenols in the short term. The early defoliation in hot climate is a agronomic practice in developing ,but is important to understand which are the most limits and advantage