Physiological responses and fruit composition of two red grape cultivars under different light regimes.

摘要

To evaluate grapevine physiological responses to light regimes, two Sardinian red cultivars were covered with two different screening plastic films (Visible (VIS) and UV-A+VIS), compared to a control sunlight exposed. From veraison until harvest light intensity and spectral quality were monitored. Canopy, berry skin and flesh temperature were continuously monitored with thermocouples inserted into berries. Plant physiological status, berry anthocyanin and total polyphenols content were correlated with the cluster thermal regimes and light exposure. No significant differences were found among the films, in canopy and clusters microclimate, and in fruit final composition. The imposed light regimes affected microclimate conditions, total polyphenols and anthocyanin contents but did not induce significant differences on plants' physiological status and berry main flesh components. The observed microclimate differences between cultivars were related to plant structure and cluster exposure.