冬小麦冠气温差及其与叶水势的相关性实验研究

Winter Wheat Canopy-Air Temperature Difference and its Relation to Leaf Water Potential

在1992和1993年田间实验的基础上,对不同水分胁迫条件下冬小麦田14时冠层温度与空气温度的差(称为冠气温差(ΔT))的季节变化及其与叶水势的关系进行了研究。结果表明,干旱处理麦田ΔT明显高于同一时刻湿润处理ΔT。随着土壤水分的逐渐消耗ΔT呈现逐渐增加的趋势,但是遇到不稳定的天气条件ΔT产生较大的波动。ΔT与叶水势间存在非线性负相关关系,本实验条件下冬小麦叶水势等于-1.9MPa时冠层温度接近于空气温度,ΔT=-1—0℃是指示冬小麦抽穗至灌浆期发生严重水分胁迫的关键性指标。

The seasonal variability of canopy-air temperature difference(△T) and the relationship between △T and leaf water potential were studied on the basis of winter wheat field experiment in 1992 and 1993. The △T on dry plot was higher than that measured at the same time on wet plot. A non-linear negative relationship between △T and leaf water potential was found. When leaf water potential reached -1.9 MPa,△T equaled 0℃. AT =- 1-0℃ could be critical in indicating winter wheat water stress.