Proximal sensing to detect symptoms associated with wheat curl mite-vectored viruses

The wheat curl mite (WCM) is microscopic, and therefore mite movement is difficult to track in the field. However, the virus complex it transmits causes observable and measurable changes to chlorophyll content and biomass. The ability to detect WCM (vectored viruses) with remote sensing was investigated by comparing vegetation indices calculated from proximal sensing data to ground-reference data obtained in the field. Of the 10 vegetation indices evaluated, the red-edge position (REP) provided the best relationship with virus symptoms observed in wheat. There was a significant and high correlation between REP and relative chlorophyll values and biomass and a significant, but lower, correlation between REP and percentage virus infection.