通过小区和大田同步调查棉花黄萎病, 在不同生育期测定病叶光谱及其色素含量。 将病叶光谱反射率、 一阶微分及相应的特征参数与色素含量进行相关分析, 建立病叶色素含量估测模型并检验。 结果表明: 病叶叶绿素a, b及a+b含量可见光反射率、 与一阶微分光谱在蓝边、 黄边和红边处与除红边振幅(Dr)外的其他光谱特征参数间均达极显著相关。 转换叶绿素吸收反射指数(TCARI)和新建归一化植被指数(NDVI［702, 758］)对叶绿素a, b及a+b含量的估测精度最高, 相对误差均小于1.3%。 考虑到NDVI［702, 758］建立的模型更实用, 可做为病叶叶绿素a, b和a+b含量的最佳估测模型。 研究结果对高光谱信息定量估测病害棉叶色素含量, 对利用高光谱监测棉花长势及病害影响评价均具有较高的实用价值。

The spectrum reflectance and pigment contents of cotton leaves infected with Verticillium wilt were measured in cotton disease nursery and field in different growth phases, and severity level of Verticillium wilt was investigated. The correlation between pigment contents of cotton leaves with Verticillium wilt and spectra reflectance, the first derivative of reflectance and spectral characteristic parameters were analyzed respectively. The estimation models about leaves pigment contents of disease cotton were established and tested. The results indicated that the correlations were best significant between chlorophyll a, b and a+b contents of leaves and spectral reflectance in visible wave bands, the first derivative spectrum at the wavelength regions of blue edge, yellow edge and red edge, and all spectral characteristic parameters (excluding red edge swing Dr). The models of transformed chlorophyll absorption in reflectance index (TCAR) and the new model of normalized difference vegetation index (NDVI ［702,758］) had best estimated precision, and the relative errors were in average within 1.3%. Given that the model of NDVI ［702,758］ is very simple and practical, it was commended as a best model to estimate chlorophyll a, b and a+b contents of disease cotton. This study shows that leaves hyperspectra data can be used to estimate the pigment contents of cotton leaves quantitatively. This conclusion has also great practice and application value for monitoring the growth state and disease influence evaluation on cotton by using hyperspectral remote sensing.