The Valpolicella area (Veneto Region, Italy) is famous for its high quality wines: Amarone and Recioto, both obtained from partial post-harvest dehydrated red grapes. The main cultivars used for these wines are Corvina and Corvinone. In this region hundreds of years ago a particular wine making process was developed to dehydrate the grape after the harvest.
The aim of this innovative work was to study how the environmental factors affected the post-harvest dehydration process.
Different vocation units were defined from a pedological survey using landscape genesis. Afterwards Corvina and Corvinone vineyards, trained with simple Guyot, were selected and observed for a three year period (2009-2011). New parameters correlated to grape dehydration rate were evaluated: quantity of epicutiuolar wax (Ew), skin thickness (ThS), bunch density (BD) and berry surface to volume ratio (S/V).
The results showed a variation of these parameters depending on the environmental variability, mainly due to pedological soil characteristics (texture, depth, soil water availability), site-altitude and exposure. The Ew, BD and S/V showed a good correlation with the kinetic of post-harvest weight loss, so the evaluation of these parameters can be used as a prediction model. This new information is useful for winemakers so they can separate the grapes depending on the growing area to reach an optimum post-harvest weight loss (from 35 % to 45 %).
Fabrizio BATTISTA (1) , Lorenzo LOVAT (1), Duilio PORRO (2), Emanuele TOSI (3), Luigi BAVARESCO (1), Diego TOMASI (1)
(1) Centro di Ricerca per la Viticoltura, Consiglio per la Ricerca e la Sperimentazione in Agricoltura, Viale 28 Aprile 26, Conegliano (TV), Italy
(2) Fondazione Edmund Mach, Centro di Trasferimento Tecnologico, via Mach 1, S.Michele a/A (TN), Italy
(3) Centro per la sperimentazione in Vitivinicultura, Provincia di Verona, Via della Pieve 64, S. Pietro in Cariano (VR), Italy
Keywords: grapevine, epicuticular wax, skin thickness, postharvest weight loss