Table 1.

Expressions of the developed models and results of model evaluation

Independent variable x	Model expressions	R2	RMSE	REP
ρ(716 nm)	CN=−1.38ln(x)+0.351	0.770**	0.272	13.31
ρ′(759 nm)	CN=1.37exp(1457.1x)	0.891**	0.181	8.85
ρ(1507 nm)	CEE=0.879exp(9.983x)	0.587**	0.644	18.69
ρ′(1954 nm)	CEE=1.497exp(3758.8x)	0.698**	0.589	17.11
ρ(1924 nm)	CCF=−395.04x+43.115	0.352*	3.951	14.27
ρ′(2370 nm)	CCF=21099x+34.299	0.480**	3.538	12.78

n=35;

^** Significant at P=0.01 (R ²=0.174);

^* Significant at P=0.05 (R ²=0.106)