Abstract:
Climate warming had a significant adverse impact on potato growing in the North Single planting region.Based on the meteorological data from 676 stations during 1961-2020 and potato phenology information,this study quantified the spatiotemporal trends of high temperatures,droughts,and their compound events across different growth periods of potato in the North Single planting region by using the crop water deficit index (CWDI),heat degree days (HDD),and compound heat-drought index (CHDI).Results indicate that the CWDI during the whole growth period of potato in North Single planting region gradually decreases from west to east.The CWDI during tuber formation period is higher than during the vegetative growth period and tuber bulking period.The average CWDI during 1991-2020 shows a decrease trend compared to that during 1961-1990.The HDD during the whole growth period of potato generally decreases with increasing latitude.The HDD in Qinghai,Liaoning,and Heilongjiang is lower than in other regions.From 1991-2020,the HDD during the vegetative growth,tuber formation,and tuber bulking period of potato in the region increased by 25-38% compared to the 1961-1990 period.Potato planted in Qinghai and northeastern China are less affected by compound heat-drought events,while the intensity of compound heat-drought event is typically slight and moderate in other regions.However,the intensity of compound heat-drought event in Xinjiang,Shaanxi,and Hebei are predominantly moderate and severe.Climate warming have increaded the area naffected by compound heat-drought events for potato planting in this region by 64%,while the area experiencing severe compound heat-drought events has increased by 93%.Excluding Xinjiang,potato yields in North Single planting region exhibit a significant negative correlation with the CWDI during the vegetative growth period and the HDD and CHDI during the tuber formation period (
P<0.05).This study quantifies the spatiotemporal trends of drought,high temperature,and the compound heat-drought event across various growth periods of potato in North Single planting region,and providing scientific insights to support climate risk avoidance and yield stability of potato under climate warming.