. 2018 Oct 10;9:1478. doi: 10.3389/fpls.2018.01478

Table 7.

Coefficients of determination of relationships obtained from simple regression analysis of destructively obtained parameters nitrogen uptake, nitrogen concentration, biomass fresh and dry weight with spectral indices (calculated as normalized difference indices) of wheat for each individual measurement date and for all dates (March 4, March 17, April 1, April 14) in 2014 together.

Spectral indices	Nitrogen uptake (kg ha^-1)					Nitrogen concentration (%)					Biomass fresh weight (kg ha^-1)					Biomass dry weight (kg ha^-1)

	4.03	17.03	1.04	14.04	All	4.03	17.03	1.04	14.04	All	4.03	17.03	1.04	14.04	All	4.03	17.03	1.04	14.04	All
590_550	0.64	0.84	0.71	0.73	0.84	0.15	0.11	0.25	0.30	0.19	0.63	0.80	0.74	0.78	0.93	0.53	0.68	0.62	0.76	0.89
624_572	0.66	0.84	0.70	0.72	0.78	0.18	0.11	0.25	0.28	0.18	0.61	0.80	0.74	0.78	0.92	0.50	0.68	0.62	0.76	0.89
710_640	0.46	0.73	0.64	0.78	0.82	0.02	0.04	0.17	0.20	0.18	0.56	0.75	0.73	0.79	0.92	0.52	0.66	0.62	0.80	0.90
760_550	0.45	0.79	0.73	0.82	0.85	0.02	0.06	0.27	0.31	0.17	0.55	0.79	0.75	0.79	0.90	0.51	0.68	0.62	0.75	0.87
760_730	0.63	0.85	0.75	0.80	0.87	0.12	0.14	0.33	0.36	0.10	0.62	0.79	0.72	0.75	0.85	0.53	0.65	0.59	0.68	0.82
780_720	0.61	0.84	0.75	0.80	0.87	0.11	0.13	0.31	0.35	0.10	0.62	0.79	0.72	0.76	0.86	0.53	0.65	0.60	0.69	0.83
780_740	0.63	0.83	0.76	0.79	0.86	0.14	0.15	0.34	0.36	0.09	0.60	0.77	0.70	0.74	0.82	0.50	0.63	0.58	0.67	0.80
780_670	0.53	0.76	0.67	0.76	0.83	0.05	0.07	0.20	0.21	0.11	0.60	0.76	0.72	0.79	0.90	0.53	0.65	0.61	0.77	0.87
800_720	0.62	0.84	0.76	0.81	0.87	0.11	0.13	0.34	0.37	0.12	0.62	0.80	0.72	0.75	0.86	0.53	0.66	0.59	0.70	0.83
820_660	0.55	0.82	0.72	0.81	0.84	0.06	0.08	0.27	0.31	0.19	0.61	0.81	0.75	0.78	0.91	0.55	0.69	0.62	0.75	0.88
850_730	0.60	0.82	0.74	0.80	0.86	0.10	0.14	0.33	0.36	0.11	0.60	0.76	0.70	0.75	0.85	0.51	0.62	0.57	0.69	0.82
952_720	0.59	0.82	0.74	0.79	0.86	0.10	0.13	0.32	0.35	0.10	0.60	0.77	0.70	0.74	0.84	0.52	0.63	0.58	0.68	0.81

Statistically significant at R² from 0.09 to 0.12, P ≤ 0.05; R² from 0.13 to 0.18, P ≤ 0.01; R² ≥ 0.19, P ≤ 0.001, respectively.