Frost risk assessment based on the frost-induced injury rate of tea buds: A case study of the Yuezhou Longjing tea production area, China

The tea tree (Camellia sinensis [L.] O. Kuntze) is a perennial cash crop, whose tender shoots and young leaves are used in tea production. Tea tree buds that have burst but have not yet been plucked may be damaged by frost, resulting in severe economic losses. And frost disasters in spring bring a serious threat to tea production in China. However, the impacts of frost disasters on tea production are not well evaluated. To address this gap, we quantified temporal and spatial changes of frost risk in the Yuezhou Longjing tea production area, which is China's largest site of green tea production. Accordingly, we developed a new frost risk index based on the percentage of frost-damaged tea buds in relation to all tea buds and its probability. The results showed that elevation was the main factor associated with frost risk. Applying the Mann Kendall test, the effects of elevation on the tea frost risk in plain areas (50-250 m) and hilly areas (251-450 m) were determined. In plain areas, the frost risks and trends for the percentage of all frost-damaged tea buds did not change significantly with elevation. In hilly areas, the frost risks increased significantly with the increasing of elevations. However, the temporal change of percentage of frost-damaged tea buds decreased significantly, and this change showed a significant decreasing trend with increasing elevation in hilly areas. This trend is conducive to tea production in the hills, which are the main Longjing tea production areas. Our findings provide a better understanding of frost risk in tea production and could offer valuable references for frost risk prevention in tea production.

Automated summary

This research quantified the frost risk in China's largest green tea production area and developed a new frost risk index, finding that elevation is the main factor associated with frost risk. In plain areas, the risk and percentage of all frost-damaged tea buds did not significantly change with elevation, while in hilly areas, the risk significantly increased with elevation, but the percentage of frost-damaged tea buds significantly decreased. This trend is beneficial for tea production in hilly areas.