Effects of Nano Silicon, Mycorrhiza, and Vermicompost on Some Physiological and Biochemical Traits of Triticale (× Triticosecale Wittmack) under Salinity Stress

To study the effects of nano silicon (Si), mycorrhiza, and vermicompost on some physiological traits of triticale under salinity stress, a factorial experiment was conducted based on a randomized complete block design with three replications in 2021‒2022. Experimental factors included salinity at three levels [no-salt (control or S0), salinity 30 (S1), and 60 (S2) mM by NaCl equivalent to 1.71, 5.53, and 8.3 dS/m, respectively], application of bio-organic fertilizers (no application (B0), application of vermicompost (B1), mycorrhiza (B2), and application both of vermicompost and mycorrhiza (B3)), and three nano Si levels (without nano Si as control (N0), application of 30 (N1), and 60 (N2) mg/L). Means comparison revealed that under 60 mM salinity conditions, application of bio-organic fertilizers and 60 mg/L nano Si (B3N2) increased chlorophyll index, relative water content and quantum yield in comparison with no application of these fertilizers and nano Si (B0N0) under severe salinity stress. However, under severe salinity stress, the application of bio-organic fertilizers and nano Si as B3N2 decreased electrical conductivity as well as hydrogen peroxide and malondialdehyde content in comparison with S2B0N0. Based on the results, application both of mycorrhiza with vermicompost and foliar application of 60 mg/L nano Si under 60 mM salinity conditions increased activity of antioxidant enzymes and compatible osmolytes in comparison with no application of these fertilizers and nano Si under no salinity. Under the highest salinity level, application of bio-organic fertilizers and nano Si as B3N2 had 30% more grain yield in comparison with B0N0. Overall, the application of bio-organic fertilizers and nano Si was beneficial for improving triticale plants' salinity resistance.