Understanding the Influence of Extreme Cold on Grapevine Phenology in South Dakota’s Dormant Season: Implications for Sustainable Viticulture

Understanding the impact of climate and environmental factors on grapevine phenology is crucial for optimizing viticulture practices in regions susceptible to extreme weather conditions. Therefore, the study was to assess how extreme cold events, such as those observed during this dormant season, affect grapevine development, offering valuable insights for vineyard management in cold-prone regions and contributing to the broader understanding of the effects of local climate on grapevine phenology. Based on our results, the 2020/2021 dormant season in Brookings and Garretson, South Dakota, exhibited significant fluctuations in minimum hourly temperatures, with particularly frigid conditions experienced in February. On February 15, 2021, both locations recorded their lowest temperatures, with Brookings reaching −32.8 °C and Garretson registering −32.01 °C. The extreme cold temperatures in February have significant implications for regional climate analysis, agriculture, and environmental studies. This study investigated the influence of extreme cold on grapevine phenology and revealed varying responses among grape cultivars, locations, and bud stages. While bud break and bud damage were significantly affected by location and grape cultivar, the interaction effect was not significant. ‘Marquette’ demonstrated higher cold resilience in terms of bud break and damage. Furthermore, the evaluation of cluster size unveiled distinct patterns of primary and secondary bud distribution among cultivars and locations, with ‘Marquette’ exhibiting resilience to dead buds. Finally, analysis of cane damage and bud break showed more severe injuries in Garretson cuttings compared to Brookings, suggesting local environmental factors affecting cane hardiness. These findings provide insights for vineyard management in regions prone to extreme cold, enhancing our understanding of the influence of local climate on grapevine phenology.