Thermal sum in the phenological phases of Niagara Rosada grapevine cultivated in Urussanga, Santa Catarina, Brazil

This study aimed to characterize the thermal requirements and phenological performance of the Niagara Rosada grapevine cultivated in the region Vales da Uva Goethe, in the south of Santa Catarina. We used the observations of an
experiment with sixteen rootstocks installed at Epagri’s Experiment Station in Urussanga, SC. The experiment was conducted in the trellis system, with spacing of 3 x 1.5m for four years. The phenology of plants was evaluated, as to the duraton, in days for each of the following periods: pruning to budding (PR-BU), budding to full bloom (BU-FB), full bloom to beginning of
maturaton (FB-BM), beginning of maturaton to harvest (BM-HA). A thermal demand was calculated using the sum of degreedays for each of the periods considering the basal temperatures of 10 and 12°C. From the obtained results we concluded that the basal temperature of 10°C is best to calculate the thermal demand of the vine. Then thermal demand for the periods of
PR-BU, BU-FB, FB-BM, BM-HA is 243, 247, 908 and 287 degree-days respectvely. A thermal requirement for the period from pruning to harvest is 1,685 degree-days.