Table 2.

Physiological, biochemical and nutritional traits reported previously related to the key-wavelengths identified in this study.

Order	PLSR Coefficient	Key-Wavelength (nm)	Physiological, Biochemical and Nutritional Traits Relate to the Key-Wavelengths (± 25 nm)
26	0.043	456	460 nm relates to chlorophyll a,b and electron transition [35].
25	0.045	482	495 nm is the longer wavelength portion of the blue band; crop-to-soil reflectance ratio is minima for blue and green bands [37].
6	0.137	505	520 nm is mainly influenced by leaf pigments, such as chlorophyll or carotenoids [38].
13	0.085	569	540 nm to 550 nm is the peak of the green band and the maximum first-order derivative in the visible spectrum [37].
15	0.075	646	660 nm relates to N [39].
8	0.122	676	670 nm relates to electron transition and chlorophyll a,b [35].
7	0.133	690	668 nm to 696 nm is chlorophyll absorption maxima [37].
18	0.070	708	In the red-edge range in which the slope and position are salient features to distinguish vigorous plants from others [37,40].
16 (17)	0.074	740
20	0.059	892	845 nm is NIR shoulder; 920 nm is the peak of NIR [41]; 910 nm relates to C-H stretch and protein [35].
23	0.054	1003	1020 nm relates to N-H stretch and protein [35].
10	0.096	1210	Not previously reported.
19	0.061	1307	Not previously reported.
22	0.055	1366	Not previously reported.
9	0.106	1395	Not previously reported.
24	0.054	1517	1510 nm relates to N-H stretch, protein and N [35,39].
17 (16)	0.074	1590	Not previously reported.
4	0.148	1686	1690 nm relates to C-H stretch, protein and N [35].
12	0.087	1739	Not previously reported.
5	0.145	1800	Not previously reported.
11	0.092	1876	1900 nm relates to O-H stretch [35].
21	0.059	1943	1940 nm relates to N-H deformation, protein and N [35].
14	0.083	2046	2060 nm relates to N-H bend, protein and N [35].
3	0.205	2106	2130 nm relates to N-H stretch and protein [35].
1	0.297	2180	2180 nm relates to N-H bend, protein and N [35].
2	0.217	2313	2300 nm relates to N-H stretch, protein and N [35].