小麦水分状况的光反射测量

    Estimation of wheat water status by reflectance measurements

    • 摘要: 反射测量可用于对作物的水分状况进行快速而经济的评估。该研究以土壤最大持水量为标准,设65%、52%、39%、32.5%、26%和19.5%共6个水处理水平。小麦叶片光反射的测量用数码相机进行,测量结果用L*a*b*颜色系统进行评估和分析。在该三维系统中,参数a*和b*分别描述绿/红和蓝/黄颜色的比例,参数L*用来描述颜色的浅淡。结果表明,随水胁迫加剧,小麦叶片光反射参数a*(绿/红)和/或b*(蓝/黄)在9个特定波段表现出有规律的增加,植株含水率与光反射参数b*之间呈线性负相关关系,其中与510~780 nm波段的光反射参数b*之间的决定系数r2最大,达到0.95。因此光反射测量可以作为小麦水分状况测量的一个重要工具。

       

      Abstract: Water stress, one of the most limiting factors in crop production, is a worldwide problem. Reflectance measurements may provide inexpensive and fast estimates of water status of crops. A pot experiment was conducted in the glasshouse with summer wheat cv. Thasos. Six different water levels were chosen based on the maximum water capacity of the soil and designed as 65%, 52%, 39%, 32.5%, 26% and 19.5% with three replications. Leaf scans of wheat plants were performed with a digital LEICA S1 PRO camera under controlled light conditions. Leaf scans were evaluated with the L*a*b*-color system. This is a three-dimensional system with parameter a* describing the green/red percentage and parameter b* the blue/yellow percentage of a color. L* represents the lightness of a color. The results showed that reflectance parameter a* and/or b* in 9 specific wavelength ranges increased along with the level of water stress. There is a linear correlation between parameter b* in the 9 wavelength ranges. The best correlation was found in the wavelength range of 510~780 nm with r2=0.95. The results indicate that reflectance measurements may provide a powerful tool for the evaluation of water status in wheat plants.

       

    /

    返回文章
    返回