A Study on the Periodicity Freeze Injury of Orange in China

In this paper, the negative accumulated temperature (daily minimum temperature < 0oC) ≤-90oC and the extreme minimum temperature ≤8oC are used as the orange heavy freeze injury index. The relationship between the orange freeze injury and different cold wave paths, intensity and spatial distribution of the extreme minimum temperature are calculated. Using the spectrum analysis, it is found that there are the period lengths of 9—10 and 3—6 years of orange heavy freeze injury caused by the negative accumulated temperature and the extreme minimum temperature in Yangtze river valley, and their regional difference is bigger. Furthermore, the forecasting for the heavy freeze injury of orange and making proposals for the orange culture have been done.