Several studies demonstrated (Baret and Guyot 1991; Wiegand et al. 1990) that NDVI is related to biomass by an exponential relationship which saturates at higher values of biomass. In this study, the vegetation index is applied at a time when biomass values are not high enough to saturate the NDVI. Therefore, CCCINDVI was developed into take into account the effects of canopy cover and N dilution within the crop (Justes et al. 1994)