@article {Gattiajev.2012.11118, author = {Matteo Gatti and Fabio Bernizzoni and Silvia Civardi and Stefano Poni}, title = {Effects of Cluster Thinning and Pre-Flowering Leaf Removal on Growth and Grape Composition in cv. Sangiovese}, elocation-id = {ajev.2012.11118}, year = {2012}, doi = {10.5344/ajev.2012.11118}, publisher = {American Journal of Enology and Viticulture}, abstract = {Crop regulation techniques applied as pre-flowering defoliation (D) and early cluster thinning performed at the same time (ECT) or at lag-phase of berry growth (LCT) were tested over three seasons on high-yielding cv. Sangiovese (Vitis vinifera L.) and compared to non-defoliated, un-thinned control (C) vines of the same cultivar. Treatment severity consisted of removing primary leaves and any laterals developed from nodes 1 to 6 in D and by thinning 50\% of clusters chosen among distal ones or those inserted on weak shoots, in the CT plots. Despite the fact that yield per vine was not as reduced in D (-32\%) as in CT treatment (-45\%) in comparison to C, early defoliated vines also had largely improved sugar and total anthocyanin concentrations and highest total phenolics. Yield components were also markedly affected by treatments: D vines showed smaller clusters and berries, leading in turn to improved cluster looseness, as well as higher relative skin and seed growth. While all crop-regulating treatments led to an increase in the final leaf-to-fruit ratio, parameters of technological maturity were essentially uncoupled as equally high Brix levels corresponded to the highest TA in D and, conversely, to lowest TA and highest pH in cluster thinning treatments. Overall results show that different final yield-grape composition patterns can be reached depending upon the principle used for crop regulation as a primary consequence of a diversified degree of compensation triggered on single yield components.}, issn = {0002-9254}, URL = {https://www.ajevonline.org/content/early/2012/03/09/ajev.2012.11118}, eprint = {https://www.ajevonline.org/content/early/2012/03/09/ajev.2012.11118.full.pdf}, journal = {American Journal of Enology and Viticulture} }