Climate change and the impact on fungus-resistant grapes varieties grown at two regions in the south of Brazil

The lower vegetative growth that occurs in regions with higher altitudes due to lower temperatures is desirable to reduce cultural treatments and maintain the photosynthetic rate at levels that are beneficial for developing vines. A pessimistic climate change scenario, with an increase in average temperature and changes in the rainfall regime, influences the varieties physiology and the incidence of diseases to which they are susceptible. This research objective is to indicate how climate changes can influence the varieties Aromera, Calardis Blanc, and Felicia which are white fungus-resistant grapes, cultivated in Curitibanos and Videira, municipalities of Santa Catarina state, Brazil, located in the regions of Planalto Catarinense and Meio Oeste Catarinense. Phenology and growing degree-days (GDD) analysis were carried out on the varieties. In the municipalities and their regions, the variables climatological indices, meteorological conditions of the 2018/19 and 2019/20 harvests, and the future scenario for 2071 to 2100 (A2) were analyzed. The future scenario predicts an average increase in precipitation of 76mm and an average temperature of 3.6ºC during vegetative growth in the regions of the evaluated municipalities. The increase in temperature reduces the cycle of varieties by 24 days, on average. This scenario predicts an increased incidence of Plasmopara viticola from October to February and Erysiphe necator from October to December. Therefore, there will be changes in the physiology and the incidence of diseases, making management research essential, aiming to reduce stress in these varieties, maintain oenological quality, and perpetuate sustainable planting.