Table 2. Coefficients of correlation between spectral indices and the index of wheat powdery mildew at different growth stages of wheat at the two plant densities during two seasons. ^a .

spectral indices	2009–2010 season								2010–2011 season
	Density 1				Density 2				Density 1				Density 2
	10.5.3	10.5.4	11.1		10.5.3	10.5.4	11.1		10.5.3	10.5.4	11.1		10.5.3	10.5.4	11.1
DVI	−0.65	−0.75	−0.68		−0.75	−0.69	−0.87		−0.83	−0.88	−0.65		−0.75	−0.82	−0.80
RVI	−0.28	−0.12	−0.50		−0.72	−0.72	−0.83		−0.48	−0.46	−0.64		−0.66	−0.56	−0.79
NDVI	−0.35	−0.21	−0.51		−0.70	−0.74	−0.83		−0.50	−0.48	−0.63		−0.64	−0.58	−0.71
GNDVI	−0.30	−0.16	−0.48		−0.69	−0.58	−0.82		−0.47	−0.44	−0.64		−0.67	−0.56	−0.75
NBNDVI	−0.35	−0.22	−0.54		−0.72	−0.74	−0.82		−0.50	−0.48	−0.62		−0.63	−0.57	−0.70
NRI	−0.36	−0.24	−0.42		−0.64	−0.65	−0.55		−0.47	−0.51	−0.37		−0.48	−0.46	−0.54
TVI	−0.62	−0.74	−0.70		−0.75	−0.67	−0.86		−0.78	−0.84	−0.66		−0.74	−0.78	−0.78
PRI	−0.34	−0.28	−0.05		−0.74	−0.75	−0.46		−0.46	−0.41	0.01		−0.77	−0.47	−0.53
PhRI	0.22	0.10	−0.20		0.11	0.11	−0.16		−0.25	−0.30	−0.59		0.42	−0.05	−0.26
TCARI	−0.29	−0.28	−0.42		−0.04	−0.08	−0.13		−0.46	−0.52	−0.45		0.08	−0.40	−0.31
MCARI	−0.31	−0.29	−0.41		−0.05	−0.09	−0.20		−0.46	−0.52	−0.45		0.08	−0.40	−0.31
RVSI	−0.49	−0.51	−0.29		−0.73	−0.59	−0.48		−0.49	−0.59	−0.31		−0.75	−0.62	−0.49
PSRI	0.53	0.33	0.19		0.77	0.75	0.60		0.50	0.51	0.23		0.65	0.51	0.53
ARI	0.38	0.42	0.17		0.85	0.74	0.47		0.54	0.62	0.19		0.75	0.51	0.50
λ red	−0.36	−0.46	0.03		−0.75	−0.37	−0.26		−0.29	−0.49	−0.26		−0.70	−0.56	0.04
dr red	−0.24	−0.62	−0.77		−0.30	−0.63	−0.51		0.04	−0.32	−0.73		−0.15	−0.35	−0.41
Σdr 680–760 nm	−0.63	−0.76	−0.70		−0.76	−0.68	−0.87		−0.79	−0.84	−0.67		−0.76	−0.83	−0.81

^aPlant density 1 and 2 represent 60 and 120 kg seed ha⁻¹, respectively.

^bValues in bold indicated the highest correlation values.