Salinity stress harms plant growth and physiological characteristics. To investigate the effect of NaCl salinity stress (without salinity stress and 100 mM salinity) and foliar spray with: control (distilled water), zinc oxide nanoparticles (40 mgL− 1), salicylic acid (1 mM), chitosan (10 mgL− 1) and zinc oxide nanoparticles encapsulated within a chitosan–salicylic acid matrix (CS-Zn-SA NPs) (40 mgL− 1) on growth and some physiological attributes of mint; a factorial experiment was conducted based on a completely randomized design. Independent effect of CS-Zn-SA NPs spraying increased plant dry weight, nitrogen, and potassium content, as well as essential oil yield. Moreover, 100 mM salinity stress reduced the mentioned traits. NaCl100 mM × spraying with CS-Zn-SA NPs enhanced total phenolics and flavonoids content. The interaction effect of NaCl100 mM × without foliar spraying enhanced proline, malondialdehyde, and sodium content. Treatment without salinity stress × foliar spraying of CS-Zn-SA NPs raised the magnesium, zinc, and iron content of mint. In general, it can be stated that the synergistic effects of combining salicylic acid, zinc, and chitosan partially enhanced the growth potential and improved physiological properties of peppermint plants under salt stress conditions. Following complementary field studies, the results would be advisable for the production section.
Al-Obaidi et al. (Thu,) studied this question.