Table 9.

Pearson correlation and linear regression analysis between grain yield and the AUC of spectral features (non-fungicide treatment block).

	UAV			SkySat			Pleiades
	r	R2adj	RMSE	r	R2adj	RMSE	r	R2adj	RMSE
G-AUC	− 0.80			− 0.73			− 0.72
R-AUC	− 0.92*	0.80*	0.35	− 0.84*	0.64*	0.47	− 0.79
NIR-AUC	− 0.55			− 0.58			− 0.60
NGRDI-AUC	0.22			0.04			0.78
NDVI-AUC	0.91*	0.79*	0.35	0.71			0.58
GNDVI-AUC	0.82*	0.60*	0.49	0.67			0.28
TVI-AUC	− 0.02			0.01			− 0.31
CVI-AUC	0.55			0.46			− 0.47
CIG-AUC	0.83*	0.61*	0.48	0.62			0.27
RGR-AUC	− 0.29			− 0.08			− 0.81
RDVI-AUC	0.57			0.37			− 0.10
VARIg-AUC	0.22			0.04			0.78
OSAVI-AUC	0.76			0.71			0.58
MSR-AUC	0.84*	0.63*	0.47	0.64			0.54
MSAVI2-AUC	0.37			0.73			0.60
RVI-AUC	− 0.93**	0.83**	0.32	− 0.73			− 0.60
SAVI-AUC	0.47			0.71			0.58
SR-AUC	0.80			0.60			0.52

*p-value < 0.05; **p-value < 0.01; and ***p-value < 0.001.