Abstract:

In this paper, the evolution characteristics (spatiotemporal distribution, persistence, intensity, etc.) of summer high temperature days and heat waves in the middle of Hexi Corridor were studied, and the effects on the growth and yield components of maize during the critical period were analyzed, providing theoretical foundations for the development of early warning of high temperature events, risk prediction, maize flowering and yield forecasting services in the region. Based on daily maximum air temperature data from June to August at meteorological stations in the middle of Hexi Corridor from 1961 to 2023, linear trend, Mann-Kendall test and other methods were used to reveal the frequency, process, intensity characteristics and evolution of high temperature weather, and to analyze the effects on the growth traits and yield components such as 100-seed weight of maize, the local dominant crop. The results indicated that high temperature weather in the middle of Hexi Corridor mainly occurred in the desert oasis from late July to early August. An abrupt change of high temperature weather took place in the late 1990s. About the number of (hazardous) high temperature days and heat waves, big interannual changes, massive occurrences in a short time and an upward trend were discovered. There was a significant negative correlation between the number of high temperature days and the spike period. The intervals between tasseling and silking stages in years with more high temperature days were equal or shorter than the climatological normal. In years with more high temperature days in the jointing-booting stage, the tasseling-silking stages were simultaneous or delayed compared to climatological normals. The number of high temperature days during and after the flowering stage was significantly negatively correlated with 100-seed weight (R=-0.8495). For every additional day, the 100-seed weight decreased by 1.345 grams. Finally, it is proposed to establish an intelligent agricultural monitoring network to predict disasters, carry out experiments on high temperature meteorological applicable technologies and screen high temperature resistant varieties to cope with high temperature risk, so as to ensure high quality and high yield of maize.

Key words: summer high temperature weather, characteristic analysis, maize, high temperature weather during the flowering stage, yield components, high temperature risk, the middle of Hexi Corridor