Responses of Yield Fluctuation of Winter Oilseed Rape to Climate Anomalies in South China at Provincial Scale

The regional differences for responses of winter oilseed rape yield to climate changes was not reported in China, and the statistical climate–yield relationships at the provincial scale in south China should be a valuable attempt. With using provincial data of climate variables and oilseed rape yields during 1978–2016, the main findings were as follows: (1) based on 14 provincial climate-induced yield index (CIYI) series for oilseed rape yield, south China could be divided into five sub-regions with different temporal variations in CIYI by using principal component analysis, and they were Yangtze River delta (Region I), central south China (Region II), southwest China (Region III), southernmost China (Region IV) and southeastern coast (Region V), respectively; (2) the correlation and regression analysis between CIYI and monthly climate variables indicated that the precipitation of April, average potential evapotranspiration of November, average potential evapotranspiration of October, average mean temperature of May, and average potential evapotranspiration of September were the key climate variables (KCV) affecting yield in Region I, II, III, IV and V, respectively; (4) among the five sub-regions, the impacts of KCV changes on yields in southwest China were more notable, and the increasing trend of average potential evapotranspiration of November caused the decrease of yield by 2.08% in 1990s and 4.24% after 2000, respectively. These results could be employed as references for the assessment and mitigation of agro-meteorological disasters in south China.