TY - JOUR T1 - Does Postveraison Leaf Removal Delay Ripening in Semillon and Shiraz in a Hot Australian Climate? JF - American Journal of Enology and Viticulture JO - Am J Enol Vitic. DO - 10.5344/ajev.2019.18103 SP - ajev.2019.18103 AU - Roberta De Bei AU - Xiaoyi Wang AU - Lukas Papagiannis AU - Massimiliano Cocco AU - Patrick O’Brien AU - Marco Zito AU - Jingyun Ouyang AU - Sigfredo Fuentes AU - Matthew Gilliham AU - Steve Tyerman AU - Cassandra Collins Y1 - 2019/06/07 UR - http://www.ajevonline.org/content/early/2019/06/05/ajev.2019.18103.abstract N2 - Grape growing areas world-wide are experiencing earlier and compressed phenology due to higher temperature which has led to excessive sugar accumulation in grapes. This is associated with negative effects on grape and wine quality and higher alcohol in wines. Recent research has shown that early, climate-related, ripening can be ameliorated by late leaf removal above the cluster zone. This practice was found to delay sugar accumulation in the berries by up to two weeks without affecting other berry chemistry parameters. Therefore, in this study, postveraison leaf removal was investigated as a canopy management technique to delay ripening in Semillon and Shiraz in a hot climate in Australia. Yield and yield components, canopy size, berry and wine chemistry and sensory were measured over four seasons for Semillon and two seasons for Shiraz. The results showed no effect of the proposed technique on delaying ripening in the first year of application for both varieties. However, on the second year of application a delay in ripening of ten days in Semillon and 20 days in Shiraz was observed. In Semillon, postveraison leaf removal did not delay ripening on the fourth year of application. No differences were observed in berry chemistry and sensory attributes in Semillon. In Shiraz, wines obtained from defoliated vines in the second season were different from control wines and characterised by attributes consistent with overripe berries such as dry fruit and jammy aromas and flavours. The results from this study showed that this technique was not effective in consistently delaying ripening in Semillon and Shiraz in a hot Australian climate. ER -