Environment features and management operations on shoot and leaves modify the canopy during the vegetative season, changing the grapevine microclimate and the ratio between photo synthetic sources (the canopy) and productive sinks (the grapes). The aim of the present study was to evaluate on several vineyards the evolution in the season of the canopy development, in order to relate the vegetative behavior of the vine with the quality of grapes at harvest. For two consecutive years canopy development was assessed on 30 Nebbiolo vineyards in the Barolo area, using the point quadrat method. Size and structure of the canopy were assessed in June and September. Yield and qualitative characteristics of the must were determined at harvest. Total leaf area measured at the end of the vegetative season was directly correlated with yield, but it was not correlated with sugars and phenolic accumulation in the grape. However, both sugar and phenolic content in the must were proportional to the increase in canopy area observed between June and September, which is affected by plant vigor and vineyard management techniques (e.g. topping). The results suggest that the quality of Nebbiolo grapes in the Barolo area is affected by environment-induced vigor on one side, and by canopy management on the other side.
Authors: CLAUDIO LOVISOLO (1), ANDREA SCHUBERT (2), ROCCO Dl STEFANO (3)
(1) Dipartimento di Colture arboree dell’Università di Torino
(2) Centro Miglioramento genetico e Biologia della Vite, CNR – Via Leonardo da Vinci, 44 – 10095 Grugliasco
(3) lstituto Sperimentale per l’Enologia, Sez. di Chimica enologica – Via P. Micca, 35 – 14100 Asti