Spatial-temporal Variation Characteristics of Chill Accumulation in Two Major Apple Production Areas in China
Deciduous fruit trees require a certain low temperature accumulation to break dormancy before flowering and fruiting normally.The objective of this paper was to study the characteristic and variation of chill accumulation in main apple producing areas in China,so as to provide a reference for the safe production of apple.Based on the daily temperature data of 34 meteorological stations in two major apple-producing areas in China from 1961-2017 and five international commonly used chill models i.e.0-7.2℃ model,Utah model,Positive Utah model,Modified Utah model and Dynamic model,we calculated chill accumulation in the two major apple-producing areas.And then the spatial-temporal variation characteristics and influencing factors of chill accumulation were analyzed and compared.We also pointed out the similarities and differences between the models,as well as the safety of future fruit tree production.The results showed that the chill accumulations obtained by the five models had nearly the consistent spatial distribution characteristic,which was high in the south and low in the north of the study area.For the 0-7.2℃,Utah,Positive Utah,Modified Utah and Dynamic models respectively,the highest values were 1717CH,1690CU,1730CU,1576CU and 76 CP in Qingdao,Shandong Province,and the lowest values were 533CH,423CU,426CU,390CU and 29CP in Weichang,Hebei Province.Linear trend analysis showed that the chill accumulation of all the sites had an increasing trend(P＜0.05).And correlation analysis also showed that the chill accumulation had positive correlation with mean winter temperature(P＜0.05),while they were negatively correlated with latitude(P＜0.01).Multiple regression analysis indicated that,among the three influencing factors of latitude,longitude and altitude,latitude contributed most to chill accumulation,followed by altitude,while the chill accumulations were insensitive to the change of longitude.In the context of climate change,the current region is still conducive to the safe and stable production of apple fruit trees.Although the results of the five models are not significantly different,it is still necessary to use multi-model to analyze and study the chill accumulation in order to avoid the influence of the instability factors in the context of climate change.
deciduous fruit treesapplechill accumulationutah modeldynamic modelclimate change
NETL
NSTL
万方数据
