Table 1.

The interaction impacts of the soil application of biochar × foliar-spraying of chitosan under varying soil moisture levels on the biochemical, phytochemical, and yield characteristics of yarrow during two years of study.

Irrigation	Biochar (kg/m2 soil)	Chitosan (g/L)	Characteristics
			Proline (μmol/g wet weight)	Peroxidase (μmol/mg protein/min)	Ascorbate peroxidase (μmol/mg protein/min)	Catalase (μmol/mg protein/min)	DPPH antioxidant capacity (%)	Biological yield (kg/ha)	Dry flower weight (kg/ha)	Essential oil content (% v/w)	Essential oil yield (L/ha)
Irrigation (80–85% F.C.)	0	0	14.4 k¶	5.45 g	30.75 h	5.96 h	30.75 h	7714.4c	1161.6c	0.29i	3.52d
		2.5	19.08i	5.93f.	32.56 h	7.31f.	32.56 h	8615.1b	1259.4b	0.31 h	3.97c
	2	0	16.66j	5.59 g	31.19 h	6.7 g	31.19 h	8899.2b	1296.4ab	0.32 g	4.2b
		2.5	21.45 h	6.3e	35.78 g	7.61ef	35.78 g	9197.7a	1323.3a	0.33 fg	4.39a
Irrigation (60–65% F.C.)	0	0	23.72 g	6.32e	38.59f.	7.95e	38.59f.	5660.7 g	805.4e	0.34f.	2.47 g
		2.5	26.5f.	6.87d	44.06e	8.97d	44.06e	6602.7e	921.5d	0.35e	3.25e
	2	0	25.21 fg	6.7d	40.26f.	8.67d	40.26f.	6050.6f.	841e	0.35e	2.99f.
		2.5	32.8e	7.15c	46.75d	9.47c	46.75d	7182.6d	948.3d	0.38d	3.64d
Irrigation (40–45% F.C.)	0	0	37.11d	7.45b	53.66c	9.81c	53.66c	4135.9j	609.2 h	0.40c	2.46 h
		2.5	46.92b	7.85a	61.75b	10.71b	61.75b	4652.9i	677.7 g	0.42b	2.79 g
	2	0	40.28d	7.82a	60b	10.65b	60b	4458.2ij	648.6 g	0.43b	2.68 g
		2.5	49.07a	7.72a	65.38a	12.51a	65.38a	5191.6 h	745.9f.	0.44a	3.29e
P-value			0.000**	0.01*	0.000**	0.000**	0.01*	0.03*	0.04*	0.00**	0.01*

¶ Different letters within a column indicate significant difference at p < 0.05 according to Duncan’s test.

*: significant at the 5% level and **: significant at the 1% level.