Table 2.

Means of plant biomass, leaf area and photosynthetic pigments in mint plants affected by biochar and chemically modified biochars under fluoride and cadmium toxicities.

Toxicity	Soil treatments	Plant biomass	Leaf area	Chl a	Chl b	Chl Total	Carotenoid	Flavonoid
		g plant-1	cm2 plant-1	mg g-1DW
Non-toxic	Non-biochar	2.8 ± 0.09b	314.7 ± 2.90c	1.91 ± 0.08 a	0.93 ± 0.03 a	2.84 ± 0.07 a	0.63 ± 0.06 a	0.57 ± 0.05 ab
	Biochar	3.2 ± 0.08a	352.0 ± 4.27b	1.89 ± 0.05 a	0.96 ± 0.08 a	2.86 ± 0.11 a	0.58 ± 0.08 a	0.52 ± 0.03 b
	Biochar-H2O2	3.2 ± 0.06a	372.3 ± 3.68a	1.96 ± 0.09 a	0.95 ± 0.09 a	2.92 ± 0.08 a	0.60 ± 0.06 a	0.59 ± 0.04 a
	Biochar- H3PO4	3.3 ± 0.05a	383.7 ± 6.39a	1.97 ± 0.10 a	0.97 ± 0.04 a	2.95 ± 0.06 a	0.61 ± 0.05 a	0.53 ± 0.08 ab
	Biochar-KOH	3.2 ± 0.09a	384.0 ± 3.72a	2.01 ± 0.06 a	0.96 ± 0.02 a	2.94 ± 0.08 a	0.61 ± 0.04 a	0.54 ± 0.09 ab
Fluoride	Non-biochar	1.9 ± 0.06def	210.7 ± 5.81i	1.49 ± 0.05 e	0.62 ± 0.02 fg	2.11 ± 0.08 g	0.34 ± 0.07 d	0.24 ± 0.06 e
	Biochar	2.1 ± 0.09cd	241.7 ± 6.25efg	1.70 ± 0.11 bc	0.76 ± 0.08 bcd	2.46 ± 0.05 bcd	0.45 ± 0.09 bc	0.32 ± 0.04 cd
	Biochar-H2O2	2.1 ± 0.08cd	252.3 ± 7.31de	1.74 ± 0.06 bc	0.80 ± 0.08 b	2.53 ± 0.09 bc	0.46 ± 0.03 b	0.33 ± 0.03 cd
	Biochar- H3PO4	2.3 ± 0.11c	259.0 ± 3.93d	1.80 ± 0.09 b	0.78 ± 0.05 bc	2.57 ± 0.06 b	0.45 ± 0.09 bc	0.34 ± 0.05 cd
	Biochar-KOH	2.2 ± 0.08cd	251.0 ± 5.17def	1.76 ± 0.04 b	0.76 ± 0.09 bcd	2.52 ± 0.07 bc	0.44 ± 0.06 bc	0.33 ± 0.04 cd
Cadmium	Non-biochar	1.6 ± 0.04f	185.0 ± 2.88j	1.30 ± 0.06 f	0.55 ± 0.04 g	1.85 ± 0.05 h	0.28 ± 0.05 e	0.20 ± 0.04 e
	Biochar	1.8 ± 0.03def	222.3 ± 4.36hi	1.55 ± 0.09 de	0.72 ± 0.11 bcde	2.28 ± 0.05 ef	0.36 ± 0.06 d	0.32 ± 0.06 d
	Biochar-H2O2	1.9 ± 0.07cdef	241.3 ± 7.12efg	1.63 ± 0.05 cd	0.71 ± 0.05 cde	2.34 ± 0.09 de	0.36 ± 0.05 d	0.34 ± 0.09 cd
	Biochar- H3PO4	2.0 ± 0.09cde	245.0 ± 3.30def	1.66 ± 0.11 cd	0.72 ± 0.08 bcde	2.37 ± 0.12 cde	0.38 ± 0.08 d	0.33 ± 0.07 cd
	Biochar-KOH	1.9 ± 0.05cdef	245.0 ± 6.32def	1.65 ± 0.07 cd	0.69 ± 0.09 def	2.35 ± 0.07 de	0.40 ± 0.08 cd	0.34 ± 0.08 cd
Fluoride + Cadmium	Non-biochar	1.7 ± 0.07ef	192.0 ± 6.12j	1.48 ± 0.02 e	0.65 ± 0.04 ef	2.15 ± 0.06 fg	0.28 ± 0.04 e	0.24 ± 0.08 e
	Biochar	1.9 ± 0.07def	217.3 ± 4.32i	1.70 ± 0.08 bc	0.78 ± 0.02 bc	2.48 ± 0.05 bcd	0.35 ± 0.07 d	0.33 ± 0.09 cd
	Biochar-H2O2	2.1 ± 0.06cd	225.3 ± 7.39ghi	1.73 ± 0.04 bc	0.81 ± 0.05 b	2.52 ± 0.08 bc	0.37 ± 0.05 d	0.38 ± 0.08 c
	Biochar- H3PO4	1.8 ± 0.05def	234.3 ± 5.92fgh	1.74 ± 0.10 bc	0.80 ± 0.07 b	2.54 ± 0.09 bc	0.36 ± 0.07 d	0.34 ± 0.05 cd
	Biochar-KOH	2.1 ± 0.06cd	234.3 ± 4.38fgh	1.69 ± 0.07 bc	0.80 ± 0.08 b	2.52 ± 0.04 bc	0.36 ± 0.09 d	0.32 ± 0.09 cd

Data represents the average of three replicates (n=3) ± standard error. Different letters in each column indicate significant difference by Tukey HSD test at p ≤ 0.05. DW, Dry weight; Chl, Chlorophyll.