Spatial-temporal Distribution and Multiple-temporal Scale Variation Laws of Chilling Damage of Maize in Northeast China
By using daily temperature data of 48 agro-meteorological stations from 1961 to 2010 and the maize growth records over the recent 20 years in northeast China, a chilling damage index of growing stages of maize is defined on the basis of heat index. The temporal-spatial distribution and periodic features of chilling damage of maize during their 4 growing stages over the past 50 years are analyzed with the methods of EOF, Mann-Kendall, and wavelet analysis. The results show that the average chilling damage intensity of maize in the whole growing stage in all areas exhibits in a significant decreasing trend, but the chilling damage trend varying between the areas presents a character of differentiation and the decreasing trend displays a kind of stepladder increasing from southwest to northeast. As for the 4 growing stages, the chilling damage index's EOF first mode shows the same tendency in the spatial change. The chilling damage intensity of 4 growing stages obviously drops, and the decreasing tendency increases gradually from the first growing stage to the forth growing stage. Sharp changes occurred all in the middle of 1990s. There is a 23 or 25-year periodic oscillation for emergence to seven-leaf stage and emergence to tasseling stage, and a 3-year oscillation for emergence to milky ripening and emergence to maturation.
chilling damagegrowth stagechilling damage indexspatial-temporal distributionperiodic oscillationnortheast China
国家科技期刊平台
NSTL
万方数据
维普
