GPC	Grain protein content
UAV	Unmanned aerial vehicle
VIs	Vegetation indices
TIs	Texture indices
SPAD	Soil–Plant Analysis Development
RMSE	Root mean square error
LAI	Leaf area index
PLSR	Partial least squares regression
RVI	Ratio vegetation index
NDRE	Normalized difference red-edge index
NPCI	Normalized pigments chlorophyll ratio index
NRI	Nitrogen reflectance index
CIred-edge	Red chlorophyll edge index
GNDVI	Green normalized difference vegetation index
OSAVI	Optimized soil-adjusted vegetation index
DTI	Difference texture index
NDTI	Normalized difference texture index
RTI	Ratio texture index