The temporal and spatial variation of high temperature and heat damage during flowering and boll setting stage of cotton in Xinjiang from 1961 to 2022
[Objective]Heat damage is the most important meteorological disaster during the flowering and boll setting stage of cotton,which severely limits the safe production of cotton in Xinjiang.The evolution characteristics of heat damage in this area are clarified,which provides a reference for the scientific formulation of disaster prevention and mitigation measures.[Methods]This research used the daily maximum air temperature of 55 national basic meteorological stations in Xinjiang cotton planting areas from 1961 to 2022,and the observation data during the flowering stage and boll opening stage of 24 cotton meteorological observation stations from 1991 to 2022.Combined with the monitoring indices of high temperature and heat damage during flowering and boll setting stage of cotton,this research revealed the temporal and spatial variation of high temperature and heat damage with different grades during cotton flowering and boll setting stage by climate tendency rate and Mann-Kendall mutation test.[Results]The results showed that the maximum air temperature,extreme high temperature(daily maximum temperature ≥38.0 ℃)and cumulative days of the extreme high temperature during the flowering and boll setting stage of cotton in Xinjiang showed a significant upward trend from 1961 to 2022,with trend rates of 0.16 ℃(10 a)-1,0.07 ℃·(10 a)-1 and 0.45 d·(10 a)-1,respectively.The frequency and intensity of high temperature and heat damage during the flowering and boll setting stage of cotton in Xinjiang have increased.From 1961 to 2022,the years of high temperature and heat damage during flowering and boll setting stage with different intensities in the cotton planting area of eastern Xinjiang subregion accounted for more than 96.0%,and the mild and moderate heat damage in the cotton planting area of southern Xinjiang subregion accounted for 88.7%and 51.6%,respectively.And the frequency of mild heat damage during the flowering and boll setting stage of cotton in the northern Xinjiang subregion was 64.5%.[Conclusion]The frequency and intensity of heat damage during flowering and boll setting stage in Xinjiang cotton planting area showed the regional characteristics of"strong in the east and weak in the west,more in the south and less in the north".Therefore,more attention should be paid in Xinjiang cotton planting areas to the breeding and application of high temperature resistant varieties,rationally adjustment of the cotton planting layout,strengthening the monitoring and early warning of meteorological disasters,and ensuring the safe and stable development of cotton production.
cottonflowering and boll setting stagehigh temperatureheat damageclimate changeXinjiang