Spectrum Characteristics of Cotton Canopy Infected with Verticillium Wilt and Inversion of Severity Level

Verticillium wilt of cotton is one of the diseases of cotton with extensive occurrence and maximal harming in our country even in the world .Hyper spectrum remote sensing with the fine spectrum information has becoming the efficient method to monitor the Verticillium wilt of cotton. The research was conducted in Xinjiang, the largest cotton plant region of China. The paper used data which was collected both canopy spectrum infected with verticillium wilt and SL (severity level) in the year 2005 2006, the quantitative correlation were analyzed between SL and canopy reflectance spectrum derivative spectrum. The tested results indicated that spectrum characteristics of cotton canopy infected with verticillium wilt had better regularity with the increase of SL in different periods and varieties. Spectrum reflectance increased in visible light region (620 700nm) with the increase of the SL, which inverted in nearinfrared region, and extreme signification in 78