. 2019 Sep 23;19(19):4123. doi: 10.3390/s19194123

Table 8.

Correlation coefficients between corn canopy nitrogen concentration and spectral indices (2018).

Spectral Index	Whole Growth Period	Jointing Period	Tasseling Period	Filling Period	Maturity Period
mNDVI = (R924 − R703 + 2 × R423) /(R924 + R703 − 2 × R423)	0.618 ^**	0.509 ^*	0.818 ^**	0.855 ^**	0.884 ^**
NDRE = (R780 − R720)/(R780 + R720)	0.696 ^**	0.470 ^*	0.600 ^**	0.673 ^**	0.808 ^**
R780/R740	0.543 ^**	0.477 ^*	0.597 ^**	0.662 ^**	0.904 ^**
ND (FD730, FD525) = (R′730 − R′525)/(R′730 + R′525)	0.566 ^**	0.563 ^**	0.721 ^**	0.636 ^**	0.936 ^**
CCCI = ((R780 − R720)/(R780 + R720))/ ((R780 − R670)/(R780 + R670))	0.511 ^*	0.612 ^**	0.755 ^**	0.774 ^**	0.884 ^**

Note: ** p < 0.01, * p < 0.05.