Impact of four hydroponic nutrient solutions and regrowth on yield, safety and essential oil profile of basil (Ocimum basilicum L.) cultivated in soilless culture systems

Figure 1.

Influence of harvest time (first and second) and HNSs on the growth parameters of basil cultivated in NGS®_

Nutrient solutions	First harvest
	Yield (g · m−2)	LFW (g · plant−1)	LDG (g · plant−1 · day−1)	DM (%)
N6 P2K6	639.33 ± 15.56 b	15.98 ± 0.39 b	0.333 ± 0.01 b	10.93 ± 0.21 b
N12 P2K6	1123.91 ± 73.23 a	28.10 ± 1.06 a	0.308 ± 0.01 b	10.42 ± 0.25 b
N6 P4K12	591.93 ± 21.02 b	14.80 ± 0.53 b	0.585 ± 0.02 a	10.41 ± 0.12 b
N12 P4K12	590.91 ± 14.39 b	14.77 ± 0.36 b	0.308 ± 0.01 b	12.49 ± 0.25 a
	Second harvest
N6 P2K6	519.85 ± 13.32 a	13.00 ± 0.33 a	0.317 ± 0.00 a	10.57 ± 0.14 b
N12 P2K6	81.00 ± 18.86 c	2.03 ± 0.43 c	0.049 ± 0.00 c	13.99 ± 0.60 a
N6 P4K12	240.09 ± 8.82 b	6.00 ± 0.25 b	0.146 ± 0.01 b	10.56 ± 0.26 b
Significance
Nutrient solution	NS	NS	***	**
Harvest time	***	***	***	***
Harvest time × nutrient solution	*	***	***	***

Influence of harvest time (first and second) and HNSs on the microbial contamination of basil cultivated in NGS®_

Nutrient solutions	First harvest
	TBC	MC	TYC
	(CFU · g−1 FW)
N6 P2K6	1.65 × 101 ± 0.93 a	1.60 × 101 ± 0.23 bc	0.11 × 101 ± 0.09 a
N12 P2K6	1.89 × 101 ± 0.93a	1.41 × 101 ± 0.53 c	3.0 × 10−1 ± 0.03 b
N6 P4K12	2.59 × 101 ± 2.84 a	1.84 × 101 ± 1.85 b	3.0 × 10−1 ± 0.02 b
N12 P4K12	2.24 × 101 ± 2.43 a	2.22 × 101 ± 0.37 a	3.0 × 10−1 ± 0.02 b
	Second harvest
N6 P2K6	8.13 × 101 ± 9.61 a	2.77 × 103 ± 288.05 a	1.40 × 102 ± 16.74 a
N12 P2K6	1.13 × 102 ± 19.64 a	1.19 × 103 ± 141.63 b	7.07 × 101 ± 14.66 a
N6 P4K12	5.87 × 101 ± 2.66 a	8.80 × 102 ± 87.17 b	2.13 × 101 ± 1.33 b
Significance
Nutrient solution	NS	**	***
Harvest time	NS	**	**
Harvest time × nutrient solution	NS	*	*

Influence of harvest time (first and second) and HNSs on the nutrient content of basil cultivated in NGS®_

Nutrient solutions	First harvest
	NO3−	CaCO3	PO43−
	(mg · g−1 FW)		(mg · kg−1 FW)
N6 P2K6	86.67 ± 6.96 c	0.84 ± 0.08 a	0.95 ± 0.06 a
N12 P2K6	562.67 ± 16.22 a	0.60 ± 0.08 a	0.56 ± 0.10 b
N6 P4K12	57.33 ± 6.66 c	0.59 ± 0.22 a	0.74 ± 0.15 ab
N12 P4K12	274.67 ± 19.64 b	0.67 ± 0.06 a	0.91 ± 0.10 ab
	Second harvest
N6 P2K6	552 ± 30.61 b	0.49 ± 0.08 b	0.71 ± 0.05 b
N12 P2K6	2272 ± 196.01 a	1.34 ± 0.27 a	1.03 ± 0.05 a
N6 P4K12	588 ± 42.11 b	0.26 ± 0.03 b	0.81 ± 0.13 ab
Significance
Nutrient solution	***	***	*
Harvest time	**	NS	*
Harvest time × nutrient solution	**	**	***

Composition of the HNSs used in the experiment (mmol ⋅L−1)_

	N6P2K6	N12P2K6	N6P4K12	N12P4K12
N	6.0	12.0	6.0	12.0
P	2.0	2.0	4.0	4.0
K	6.0	6.0	12.0	12.0
Ca	2.5	2.5	2.5	2.5
Mg	2.0	2.0	2.0	2.0

Influence of harvest time (first and second) and HNSs on the EOs composition of basil cultivated in NGS®_

Compounds (%)
First harvest
Nutrient solutions	Eucalyptol	Linalool	Camphor	Borneol	α-Terpineol	Bornyl acetate	Eugenol	β-Elemene	(E)-α-Bergamotene	Germacrene-D	γ-Cadinene	α-Cadinol
N6P2K6	10.58 ± 1.14 b	35.77 ± 3.52 a	0.82 ± 0.01 a	-	1.17 ±0.00 a	4.39 ± 0.51 b	5.41 ± 1.44 ab	0.40 ± 0.10 a	25.72 ± 0.30 b	3.70 ± 0.48 a	4.35 ± 0.19 a	7.69 ± 0.57 c
N12P2K6	8.29 ± 0.10 b	22.57 ±6.02 ab	0.43 ± 0.02 b	-	1.01 ±0.26 a	4.11 ± 1.08 b	3.00 ± 0.84 ab	0.50 ±0.20 a	31.53 ± 2.61 ab	5.61 ± 1.04 a	6.74 ± 2.12 a	16.22 ±0.26 a
N6P4K12	14.91 ± 1.49 a	32.43 ± 1.71 a	0.93 ±0.16 a	0.22 ± 0.01	1.47 ±0.28 a	4.52 ± 0.18 b	6.39 ± 0.81 a	0.80 ± 0.04 a	23.54 ± 2.70 b	3.75 ± 0.40 a	3.92 ±0.38 a	7.12 ± 0.96 c
N12P4K12	10.18 ± 021 b	14.32 ± 3.57 b	0.45 ± 0.05 b	-	O.87± 0.13 a	7.73 ± 0.60 a	1.73 ± 0.27 b	0.37 ± 0.07 a	41.99 ± 5.45 a	4.32 ± 0.27 a	6.74 ± 1.20 a	11.29 ± 1.23 b
Second harvest
N6P2K6	-	12.31 ± 1.92 b	0.07 ± 0.07 b	0.56 ± 0.07 b	2.25 ± 0.63 b	1.25 ±0.22 a	35.86 ± 3.93 b	0.24 ± 0.24	16.17 ± 0.77 a	3.13 ±0.08 a	5.50 ±0.18 a	22.72 ± 8.52 a
N6P4K12	1.75 ± 0.24	33.91 ± 10.25 a	1.25 ±0.62 a	1.76 ± 0.70 a	5.89 ± 1.87 a	0.36 ± 0.36 b	49.08 ±9.89 a	-	1.38 ± 1.28 b	0.25 ± 0.25 b	0.40 ± 0.25 b	3.89 ± 3.06 b
Cultivated in soil (%)	2.38	24.68	0.56	2.48	1.81	1.57	15.19	1.11	1.06	1.56	2.39	9.88