导数光谱在棉花农学参数测定中的作用

Approach the action of derivative spectra for determining agronomic parameters of cotton

通过大田和室内试验,测定了2个品种的棉花冠层、完全展开倒3叶在不同时期的高光谱反射率及对应叶片的叶绿素、类胡萝卜素含量,分析并证实了棉花导数光谱对消除土壤背景影响及寻找特征波长方面的作用.将导数光谱用于棉花农学参数的测定,发现棉花冠层和叶片光谱都存在红边位移现象,并且红边参数(红边位置、红边幅值、红边面积)与叶面积指数、鲜叶质量、干叶质量和叶绿素含量有显著相关,从而证明用棉花导数光谱测定它的某些农学参数的可行性.

The hyperspectral reflectances of the canopy, the third unfold leaves from the top of two varieties of cotton were measured by a ASD FieldSpec Pro FR^(TM) in field and indoor in different stages. The concentrations of chlorophyll and carotenoid of leaves corresponding to the spectra were determined. The action of derivative spectra for eliminating the influence of soil backgrounds and determining some characteristic wavelengths of cotton was analysed and confirmed. With applying the derivative sprctra to determining agronomic parameters for cotton, there were the phenomena of displacement for their spectra of canopies and leaves. The leaf area indices, fresh leaf mass, dry leaf mass and the chlorophyll contents were significantly correlative to the red edge parameters (the position of red edge λ_(red), the slope of red edge D_(red) and the area of red edge S_(red)). This indicated it was feasible to determine some agronomic parameters of cotton by the derivative spectra.