Biostimulant-induced drought tolerance in grapevine is associated with physiological and biochemical changes

Chemical and Biological Technologies in Agriculture

Table 5 Influence of biostimulants on chlorophyll content of grapevine leaves cv. ‘Yaghouti’ under WW and DS conditions

Irrigation regimes	Biostimulants	Chlorophyll a (mg g FW⁻¹)	Chlorophyll b (mg g FW⁻¹)	Total chlorophyll (mg g FW⁻¹)
WW	CON	10.53 ± 0.28 ab	7.13 ± 0.10 c	17.67 ± 0.33 b
	AA	11.24 ± 0.22 a	8.10 ± 0.09 a	19.34 ± 0.15 a
	HA	10.70 ± 0.26 ab	7.77 ± 0.13 ab	18.47 ± 0.15 ab
	FA	10.93 ± 0.45 ab	7.82 ± 0.17 ab	18.75 ± 0.28 ab
	SE	10.91 ± 0.07 ab	7.58 ± 0.08 b	18.50 ± 0.10 ab
DS	CON	8.73 ± 0.75 d	5.09 ± 0.10 g	13.83 ± 0.85 d
	AA	9.03 ± 0.85 d	6.96 ± 0.15 cd	16.00 ± 0.91 c
	HA	9.33 ± 0.70 cd	6.73 ± 0.25 de	16.06 ± 0.95 c
	FA	9.63 ± 0.47 cd	6.43 ± 0.32 ef	16.06 ± 0.70 c
	SE	10.03 ± 0.30 bc	6.16 ± 0.47 f	16.20 ± 0.75 c
Significance
Irrigation regime		**	**	*
Biostimulants		**	**	**
Irrigation regime × biostimulants		**	*	**

Mean values followed by the similar letters within a column are not significantly different from each other at P ≤ 0.05 (Duncan’s multiple range test). * and ** are significant at P ≤ 0.05 and at P ≤ 0.01, respectively. Values are means of three replicates ± SD