Fig. 4

Effects of biostimulants and salinity levels on anthocyanin (a), total phenol content (b) and total flavonoid content (c) of cluster bean. NSi1, NSi2 and NSi3 treatments: foliar applications of 50, 100 and 200 mg L− 1 SiO2-NPs; Si1, Si2 and Si3 treatments: foliar applications of 50, 100 and 200 mg L− 1 Na2SiO3; C treatment: foliar applications of distilled water; S1, S2 and S3 treatments: 0, 6, and 12 dS m− 1 NaCl. Different letters above the columns indicate statistically significant differences at p ≤ 0.05 according to LSD test. * and **: significant at p ≤ 0.05 and p ≤ 0.01, respectively and ns: non-significant. Data shown are means of three replicates per treatment.