温室番茄缺素叶片偏振反射特征分析

为提高番茄植株营养胁迫定量分析模型的精度，探究偏振检测在植物单叶尺度进行无损检测的优势，利用自行研制的偏振反射光谱系统检测不同生长期温室番茄缺素叶片偏振反射特征。对影响番茄单叶偏振反射的主要因素：方位角、入射天顶角、探测天顶角、光源偏振片起偏角度、探测器偏振片起偏角度进行了讨论，通过正交试验的极差分析获取光谱仪各测量角度参数的优水平，并通过实验进一步验证，最终分析得到偏振光谱系统检测番茄缺素叶片的角度组合及主次排序为：入射天顶角60°、光源起偏角度0°、探测器起偏角度45°、探测天顶角45°、方位角180°，在此基础上对不同生长期的缺氮、缺磷、缺钾叶片以及不同缺素程度的叶片进行分析比较，结果显示偏振反射比随番茄叶片的生长周期呈现正相关关系，缺素和营养过量均能导致偏振反射比的下降，偏振反射比在结果期和采收期的降幅较为明显。对于偏振反射光谱在植物单叶尺度营养快速检测的深入研究具有一定的理论和实践意义。

Study on the Polarized Reflectance Characteristics of Single Greenhouse Tomato Nutrient Deficiency Leaves

In order to improve accuracy of quantitative analysis model for the greenhouse tomato nitrogen, phosphorus and potassium nutrient stress, and explore the advantages of polarization non-destructive detection in single-leaf plants scale, polarized reflectance characteristics of greenhouse nutrient deficiency tomato leaves in different growing seasons and different deficiency extents were both examined via means of polarized reflectance spectroscopy system, which was self-developed by the research group. The main factors with effects on the polarized reflectance characteristics of tomato leaves were discussed, such as incident zenith angle, azimuth angle, detection zenith angle, light source polarizer degree, and detector polarizer degree. Experiments were carried out to verify the optimum level of above five parameters by means of range analysis of orthogonal experiments, through that way we can know the best angle combination of five parameters. Based on the above analysis, the angle combination and sorting of detecting tomato nutrients deficiency leaves via means of polarization spectroscopy system were obtained as follows: incident zenith angle 60°, light source polarizer degree 0°, detection zenith angle 45°, detector polarizer degree 45° and azimuth angle 180°. At the same time, both the spectra of nitrogen, phosphorus and potassium deficiency leaves in different growth stages and different deficiency extent leaves were compared with each other. Results show that there is a positive correlation between the greenhouse nutrient deficiency tomato leaves growth cycle and tomato leaves polarized reflectance spectra. Nutrient excess or nutrient deficiency can both lead to polarized reflectance decline and polarized reflectance decline extent of greenhouse tomato leaves is more obvious during the fruiting and harvest period. This paper has a certain theoretical and practical significance in the research on nutrition rapid detection on the plant single leaf scale by means of polarized reflectance spectrum.