To establish an early monitoring model of pine wood nematode disease suitable for Sichuan Province.From June to September 2020,combined with the biological characteristics of Monochamus alternatus,the spectral image of experimental samples selected in the field was carried out by handheld hyperspectral imager,and the spectral curves were processed and extracted by ENVI software.The results showed that:(1)After 5 times of image collection,the target plants showed typical symptoms from the initial stage of infection to withered and yellow death,and the spectral reflectance of infected and control plants was significantly different at each stage.(2)The weighted average of the variance of spectral reflectance at different time in different bands was carried out to extract four sensitive bands,for 488.7 nm,550.8 nm,682.2 nm and 779.8 nm.(3)Based on regression fitting of sensitive bands and vegetation index,EVI index type early inversion monitoring model of 3 bands was established,namely K=0.6874e0.7293×EVI,and plant susceptibility could be qualitatively judged by Kvalue.
维普
万方数据