冬小麦条锈病的光谱特征及遥感监测

Hyperspectral character of stripe rust on winter wheat and monitoring by remote sensing

该文通过人工田间诱发不同等级条锈病 ,在不同生育期内对不同发病等级 (不同病情指数 )的冬小麦条锈病冠层光谱进行测定 ,并同步进行条锈病病情指数的调查。定性和定量地分析了病害区与对照区处理的冬小麦冠层光谱在绿光区、黄光区和近红外区反射特征差异及叶绿素含量变化 ;并将病情指数及光谱数据进行相关分析 ,研究表明 :63 0～ 687nm、740～890nm及 976～ 13 5 0nm为遥感监测条锈病的敏感波段 ;绿光区、近红外平台处及黄光区的冠层光谱反射率分别随病情的加重呈明显的上升、下降与上升趋势 ;条锈病的红边发生蓝移 ;叶绿素含量随条锈病的病情指数的增大而下降 ;试验证明在条锈病害田间病叶率为 5 %时的最佳防治时期内 ,高光谱可以对冬小麦条锈病害做出早期诊断。并在此基础上建立了遥感监测条锈病病情指数的多波段 (长 )下的组合诊断模式的定量模型。该研究为今后通过航空、航天遥感大面积监测冬小麦条锈病提供了理论依据。

Canopy reflectance of winter wheat infected with different levels (namely different Disease Incidence) stripe rust were measured through artificial inoculation. The DI (Disease Incidence) was also investigated at the same time. Further, the correlation between the DI and the spectral data was analyzed. 630～687 nm, 740～890 nm and 976～1350 nm were found as sensitive bands to DI of winter wheat stripe rust. Some inversion models for monitoring winter wheat stripe rust, therefore, have been established. The spectrum feature and difference of winter wheat stripe rust at green, yellow and near infrared band were studied qualitatively and quantitatively. The canopy reflectance at green, yellow and near infrared bands was down, up and down, respectively and the chlorophyll content was down when the stripe rust disease becomes more serious. And the red edge position shifted to the blue. It indicated that hyperspectral has the ability to diagnose the early disease symptom within the best forecast time (under 5% of total leaves infected by stripe rust) and provided theoretic foundation to further monitor winter wheat stripe rust at large scale using airborne and airspace remote sensing data.