Reflectance Signatures Developed from Multi-Spectral Imaging of Peanut (Arachis hypogaea L.) Expressing Visible Herbicide Injury

Abstract

Multi-spectral imaging can be used to define a number of abiotic and biotic stresses associated with crop production and management. Research was conducted during 2004 and 2005 to develop spectral signatures of peanut leaves expressing visual symptoms of herbicide injury. Single leaf measurements using an artificial light source were used to develop spectra ranging from 350 to 2500 nm grouped into specific categories. Reflectance was determined for plants treated with acifluorfen, bentazon, clethodim, imazapic, paraquat, or 2,4-DB at 3 and 24 h and 3 and 6 d after application. Reflectance following herbicide applications was significant at bands 470-500 nm, 500-590 nm, 800 nm, and UMIR, at 3 and 24h after treatment and for bands 470-500 nm, 500-590 nm, 680-700 nm, 800 nm, and UMIR at 3 and 6d after treatment. Differences in reflectance were observed when comparing herbicides with different sites of action, especially when measurements were taken 3 and 6 d after treatment. These results indicate that there is potential for multi-spectral imaging to be used to discriminate among herbicides with different sites of action.