Impact of Silicon Application on Physiochemical Traits of Vigna radiata Exposed to Salinity Stress

Salinity stress affects crop yields worldwide. Mungbean, a popular grain legume with protein-rich seeds, is glycophytic and vulnerable to saline stress. Silicon has become a key ingredient that boosts plant enzymatic antioxidant activity and osmoprotectant synthesis, promoting stress tolerance.

In chloride-dominated salinity conditions of 4 and 6 dSm^-1, sodium meta-silicate administration strategies were examined in salt-affected mungbean (MH421). Two application strategies were used: foliar spraying at 50 mg/l and 100 mg/l at 30 and 45 DAS and soil addition at 50 mg/kg soil as a solution during planting. The effects of these treatments were examined at 33 and 48 DAS, three days following foliar sodium meta-silicate application.

Salinity stress reduced dry weight, nodule counts, gas exchange characteristics and plant water relation features, although Si treatment buffered the detrimental effect to a varied amount. Best effects were obtained with 100 ppm foliar application. Lipid peroxidation and electrolyte loss increased with salinity stress, while Si reduces these losses by scavenging free radicals. Silicon supplementation lowered Na+ and increased K+ absorption. Also, Si altered photosynthetic machinery, Na⁺/K⁺ homeostasis, osmolyte synthesis and oxidative stress in mungbean to reduce salinity stress and increase seed yield.