Monitor On The Chlorophyll Content Of The Selenium-rich Tartary Buckwheat By Using The Spectral Transform Methods

In this experiment,different selenium levels were treated in the flowering stage of the bitter buckwheat,and the chlorophyll content of tartary buckwheat was used as the dependent variable.The original canopy spectrum and five kinds of spectral transformation were used as independent variables to analyze the different spectral transformations and chlorophyll content.The relationship between the chlorophyll content monitoring PLSR and the full spectrum model of chlorophyll content monitoring was carried out.Then,the canopy spectral characteristic band model of Tartary buckwheat extracted by SPA+SMLR was used to compare the two models and select the optimal canopy spectral transformation mode for chlorophyll content monitoring of Tartary buckwheat.Canopy spectral transformation.Research indicates:(1)On the 5th,10 th and 15 th day after the application of selenium in the flowering stage of tartary buckwheat,the chlorophyll content of the applied selenium and tartary buckwheat showed the same trend with the progress of the growth process,that is,the chlorophyll content of the applied selenium and tartary buckwheat increased first and then decreased.The chlorophyll content in the treatments of selenium was significantly reduced from the difference to the difference.(2)Under the same selenium level,the spectral reflectance of the bitter canopy of different growth processes has a certain regular variation,and in the range of visible light and near-infrared,it shows a decrease with the progress of the growth process.Trends under different selenium levels,there is a certain difference in the spectral reflectance of the bitter canopy in the same growth process.In the visible light band of bitter buckwheat,the spectral reflectance of the canopy is not obvious,and it is in the near-infrared band of bitterness.Its reflectivity shows a significant decrease with the increase of selenium level,and there is an absorption valley at the red light(680 nm),which is opposite to the change of the near-infrared band.(3)Compared with the original canopy spectral data(T0),the spectral curve characteristics of the spectral transformation(such as reciprocal,logarithmic,square,cubic,etc.)without first-order derivativetransformation are not obvious,and the The spectral characteristic information presented by the spectral transformation(T5)of the order derivative processing is more obvious,and can effectively remove the influence of linear or near linear noise.(4)Using partial least squares(PLSR)to perform full spectrum modeling of bitter primordial canopy spectral data and transformed canopy spectral data for T0,T1,T2,T3,T4,T5,combined with the best factor for PLSR modeling The model obtained the best results by the first-order derivative transformation of the tartary canopy spectrum(T5)(Rc2=0.942,RMSEc=0.129,RPDc=3.069;Rv2=0.619,RMSEv=0.498,RPDV=1.928).(5)The continuous spectral projection(SPA)was used to extract the spectral bands of T0,T1,T2,T3,T4,T5.It was found that the characteristic bands of the bitter chlorophyll content and the spectrum of the tartary canopy were sensitive in the region of 400-700 nm(visible light band)and 700-1250 nm(near infrared band).(6)The spectrum characteristic bands of tartary buckwheat canopy were extracted by SPA.The spectral monitoring model of tartary buckwheat chlorophyll content was established by SMLR.The full spectrum model of tartary canopy was established by PLSR to obtain the first derivative of the original canopy spectrum.The transformation process(T5)(Rc2=0.783,RMSEc=0.237,RPDc=2.823;RV2=0.574,RMSEV=0.481,RPDV=1.952)model performed best.