利用烟叶光谱植被指数快速监测烤烟成熟度

Rapid Monitoring Maturity of Flue-cured Tobacco with Spectrum Vegetation Index of Fresh Leaves

为了快速定量监测烤烟成熟度，对两种施肥模式下烤烟中、上部鲜烟叶进行了光谱分析，研究了不同成熟度等级烟叶叶绿素、类胡萝卜素含量及类胡萝卜素／叶绿素（类叶比）与一阶微分光谱及植被指数的关系。结果表明：在可见光波段烤烟不同成熟度鲜烟叶光谱反射率随着成熟度的提高而逐渐升高，在近红外波段则逐渐降低；560，660，710和1100nm可作为监测烤烟鲜烟叶成熟度的敏感波段；比值植被指数RVI（1100，660）与叶绿素含量的相关系数最高（r=0．984），所构建模型能较好地监测烟叶成熟度（R2=0．9029）。当RVI（1100，660）处于2．81～3．47范围时，中部叶成熟；小于2．72时，中部烟叶过熟；大于3．75时，中部叶未达到成熟状态。

In order to rapidly and quantitatively monitor the maturity of flue-cured tobacco, the spectral analysis of middle and upper tobacco leaves under two fertilizer application modes was conducted, and the relationships of chlorophyll content, carotene content and the ratio of carotene to chlorophyll in fresh leaves at different maturity stages with first derivative spectra and vegetation index were investigated. The results showed that with the increase of maturity, the spectral reflectance of fresh leaves increased gradually in visible bands, while decreased gradually in near-infrared bands. The wavelengths of 560, 660, 710 and 1100 nm could be used as the sensitive bands for monitoring the maturity of fresh leaves. There existed the highest correlation coefficient （r=0.984） between ratio vegetation index （RVI） （1100, 660） and chlorophyll content, and the developed model could well monitor the maturity of fresh leaves （R2 = 0.9029）. When the value of RVI （1100, 660） ranged from 2.81 to 3.47, middle leaves were mature; when it was lower than 2.72, middle leaves became over mature; when it was higher than 3.75, middle leaves were unripe.