. 2022 Jul 18;13:910714. doi: 10.3389/fpls.2022.910714

TABLE 2.

Effect of different levels of soil applied Cu (0, 30, or 60 mg kg^–1) and/or MEL (30, 40, or 50 μM) on SPAD chlorophyll values, stomatal conductance (g_s) (mol m^–2 s ^–1), net photosynthetic rate (P_N) (M CO₂ m^–2 s ^–1), internal CO₂ concentration (C_i) (ppm), transpiration rate (E) (mol m^–2 s ^–1), and leaf area (cm²) of Brassica juncea at 45 DAS.

Treatments	SPAD	gs	P _N	C _i	E	Leaf area
Control	40.80 ± 0.77^cd	0.067 ± 0.0025^c	14.71 ± 0.28^c	310 ± 5.86^d	3.92 ± 0.074^d	34.29 ± 0.65^cd
Cu (30 mg kg^–1)	36.87 ± 0.70^ef	0.060 ± 0.0023^ef	12.79 ± 0.24^d	262 ± 4.96^g	3.51 ± 0.066^fg	31.89 ± 0.60^de
Cu (60 mg kg^–1)	33.04 ± 0.62^g	0.049 ± 0.0019^h	10.93 ± 0.21^f	220 ± 4.16ⁱ	2.95 ± 0.056^h	27.84 ± 0.53^f
MEL (30 μM)	45.25 ± 0.86^b	0.093 ± 0.0035^b	18.55 ± 0.35^b	352 ± 6.66^c	4.32 ± 0.082^b	38.56 ± 0.73^b
MEL (40 μM)	49.59 ± 0.94^a	0.102 ± 0.0039^a	20.61 ± 0.39^a	401 ± 7.59^a	5.33 ± 0.101^a	42.27 ± 0.80^a
MEL (50 μM)	47.25 ± 0.89^ab	0.097 ± 0.0037^ab	19.44 ± 0.37^a	371 ± 7.02^b	4.79 ± 0.091^ab	39.11 ± 0.74^b
Cu (30) + MEL (30 μM)	39.60 ± 0.75^d	0.065 ± 0.0025^de	13.57 ± 0.26^cd	288 ± 5.46^ef	3.84 ± 0.073^fg	35.08 ± 0.66^c
Cu (30) + MEL (40 μM)	42.35 ± 0.80^c	0.068 ± 0.0026^d	14.85 ± 0.28^c	312 ± 5.91^d	4.05 ± 0.077^c	35.95 ± 0.68^c
Cu (30) + MEL (50 μM)	40.68 ± 0.77^cd	0.066 ± 0.0025^d	14.25 ± 0.27^cd	296 ± 5.59^de	3.91 ± 0.074^d	35.48 ± 0.67^c
Cu (60) + MEL (30 μM)	36.78 ± 0.70^ef	0.055 ± 0.0021^f	12.11 ± 0.23^de	249 ± 4.70^h	3.51 ± 0.066^fg	32.62 ± 0.62^de
Cu (60) + MEL (40 μM)	39.93 ± 0.76^d	0.059 ± 0.0022^ef	13.46 ± 0.25^d	292 ± 5.51^e	3.85 ± 0.073^de	34.64 ± 0.66^cd
Cu (60) + MEL (50 μM)	37.77 ± 0.71^e	0.056 ± 0.0021^f	12.58 ± 0.24^d	268 ± 5.06^g	3.61 ± 0.068^f	33.65 ± 0.64^d

Data shows the mean ± standard error. Same letters indicate that there is no significant difference at P < 0.05.