###### Abstract  
Overwintering frost damage is a major challenge for the wine grape industry in northern China. This study investigates overwintering treatments to improve survival rates and mitigate frost damage in the wine grape production area of the northern foothills of the Tianshan Mountains. Seven overwintering treatments were tested: soil-covered striped cloth, striped cloth, sandwiched striped cloth, thickened striped cloth, double-layered striped cloth, heat-insulating striped cloth, and heat-insulating sandwich striped cloth. Temperature and humidity were continuously monitored during the overwintering period, both aboveground and at depths of 20 and 40 cm underground. By analyzing temperature trends, the duration of low temperatures, and temperature fluctuations, comprehensive overwintering indices were derived through principal component analysis to assess heat retention, moisture preservation, and the impact on grapevine survival. The results showed that the sandwiched striped cloth treatment provided the best insulation, with a 4.4 \({}^{\circ}\)C higher minimum daily temperature and a 356% increase in overwintering indices compared to striped cloth alone. The double-layer striped cloth treatment also improved safety, with a 130% increase in overwintering indices. Other treatments, including the soil-covered and the heat-insulating striped cloth, showed reduced performance. The sandwiched striped cloth and double-layer striped cloth treatments are recommended for northern China's wine grape regions, with further research needed to evaluate their economic viability. Vitis vinifera; frost-induced damage; overwintering; temperature and humidity profiles; principal component analysis +
Footnote †: journal: Applied sciences  
0000-0002-2300-3300-3300-3300-3300-3300-3300-3300-3300-3300-3300-33000-3300  
cultivation of cold-resistant wine grape cultivars, and the deployment of heating apparatuses. However, soil burial techniques--though historically prevalent in certain viticultural practices--are currently adopted by only a minority of growers for frost protection [34]. Traditional soil-covered overwintering that involves covering vines with soil in planting trenches for insulation is labor-intensive, lacks mechanization, provides uneven root insulation, and risks branch damage [5]. As an alternative, researchers have proposed a burial-free overwintering method that uses thermal insulation materials instead of soil burial [1]. Research by [PERSON] et al. revealed that combining chemical fiber blankets with soil cover can significantly enhance temperature regulation, branch sprouting rates, and fruit quality by improving the soil moisture content compared with simple soil mulching [6]. [PERSON] et al. demonstrated that materials such as grass thatch and trellis film, or polypropylene black film with trellis film, ensure the safe winter survival for wine grapes in the Helan Mountain foothills, offering similar thermal benefits to soil-covered methods while reducing mechanical damage and ensuring uniform budding for the next season [7]. New insulation materials such as polyethylene, glass wool, and polystyrene exhibit superior thermal performance, further advancing non-buried overwintering techniques [8; 9]. The northern foothills of the Tianshan Mountains constitute a prominent viticultural region in Xinjiang, renowned for its production of high-quality wine grapes [10]. Cabernet Sauvignon (_Vitis vinifera var._ Cabernet Sauvignon) dominates the vineyards, accounting for 80% of cultivation. Notably, the region's environmental parameters--including solar radiation, diurnal temperature variations, latitude, and soil composition--exhibit striking similarities to those of Bordeaux, France, the ancestral terroir of Cabernet Sauvignon [11]. This unique terroir makes this region ideal for cultivation of Cabernet Sauvignon. Cabernet Sauvignon is a wine grape variety with limited cold resistance and thus is highly susceptible to frost damage during the overwintering period [12].