Introducing the Yellow Flowering Index - YFI

This study proposes the Yellow Flowering Index (YFI) to detect yellow flowers in agricultural crops and ecosystems. The YFI addresses a gap in traditional spectral indices, which do not capture the characteristic reflectance of flowers with specific colors. Using spectroradiometry, the reflectance of yellow flowers and healthy leaves was estimated, and the data were simulated for the MSI/Sentinel-2 sensor bands. Time series of vegetation indices were compared with the YFI during the flowering cycle of sunflowers in an area of Goiás state, located in the central-western region of Brazil. The YFI demonstrated superior sensitivity in identifying flowering, particularly compared to traditional indices, which typically show a decline during this phase. The YFI has proven to be a promising tool to complement the phenological monitoring of crops with yellow flowers.