@article {Gatti325, author = {Matteo Gatti and Fabio Bernizzoni and Silvia Civardi and Stefano Poni}, title = {Effects of Cluster Thinning and Preflowering Leaf Removal on Growth and Grape Composition in cv. Sangiovese}, volume = {63}, number = {3}, pages = {325--332}, year = {2012}, doi = {10.5344/ajev.2012.11118}, publisher = {American Journal of Enology and Viticulture}, abstract = {Crop-regulation techniques applied as preflowering defoliation (D), early cluster thinning at preflowering (ECT), and cluster thinning at lag-phase of berry growth (LCT) were tested over three seasons on high-yielding Vitis vinifera L. Sangiovese and compared to non-defoliated, unthinned control vines. Treatment severity consisted of removing primary leaves and any laterals developed from nodes 1 to 6 in D and of thinning 50\% of clusters chosen from among distal clusters or those inserted on weak shoots in ECT and LCT plots. Although yield per vine was not as reduced in D (-32\%) as in ECT and LCT treatments (-45\%) as compared to the control, D vines also had largely improved sugar and total anthocyanin concentrations and the highest total phenolics. Yield components were also markedly affected by treatments: D vines had smaller clusters and berries, leading to improved cluster looseness and to 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 titratable acidity in D and, conversely, to lowest titratable acidity and highest pH in ECT and LCT. Overall results showed that different final yield-grape composition patterns can be reached depending on the technique 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/63/3/325}, eprint = {https://www.ajevonline.org/content/63/3/325.full.pdf}, journal = {American Journal of Enology and Viticulture} }