Differentiating stress induced by greenbugs and Russian wheat aphids in wheat using remote sensing

Outbreaks of greenbug and Russian wheat aphid appear in the Great Plains almost every year and have had significant impacts on wheat yields. Early detection of aphid infestation is a critical part of integrated pest management (IPM) for wheat production. A study was done to determine the feasibility of using remote sensing techniques to detect stress in wheat caused by aphid infestation. The purpose of this greenhouse study was to characterize and differentiate stress in wheat due to infestation by greenbugs and Russian Wheat aphids using a hand-held Cropscan radiometer. Reflectance data and derived vegetation indices from the 16 bands of the radiometer were analyzed using SAS PROC MIXED statistical analysis procedure. Results show that it is possible to detect the stress caused by the two aphid species and to discriminate between the two aphid-induced stresses in wheat using remote sensing. Ratio-based vegetation indices (based on 800/450 nm and 950/450 nm) were found useful in differentiating the two stresses in wheat. However, more canopy-level-studies are needed to identify bands and indices that might have potential to differentiate the two stresses on wheat under field conditions.