REMOTE SENSING TO ESTIMATE CHLOROPHYLL CONCENTRATION IN SPINACH USING MULTI‐SPECTRAL PLANT REFLECTANCE

ABSTRACT. The presence of nitrogen in soil and chlorophyll in plants are directly related; thus, chlorophyll may be used as an indirect indicator of nitrogen levels in fertilizer management systems. This research investigated a non‐destructive method of determining chlorophyll content and concentration in field‐grown spinach. Biomass was estimated with percent vegetation coverage based on images taken with a multispectral imaging system. Chlorophyll yield was estimated using reflectance‐based NDVI from a GreenSeeker hand‐held optical sensor and a multispectral imaging system. Strong correlations were found between reflectance‐based NDVI and chlorophyll yield (R2 = 0.92), between NDVI and biomass (R2= 0.94), and between biomass and projected plant area (R2 = 0.96). Combined parameter estimators of chlorophyll concentration had low correlation