Inducing Salinity Tolerance of Rosemary (Rosmarinus officinalis L.) Plants by Chitosan or Zeolite Application

Aims: Rosemary (Rosemarinus officinalis L.) is the foremost economically medicinal plants worldwide, its production like other crops affected negatively by environmental stresses. The adverse effects of salinity on crop production are more drastic. Application of chitosan or zeolite might considerably restore the plant productivity under the environmental stress. The present investigation aimed to evaluate the role of chitosan or zeolite on counteracting the deleterious impact of salinity on rosemary growth, oil percentage and its chemical compositions

Study Design: A factorial experiment was done in a randomized complete block design system with five replications.

Place and Duration of Study: The pot experiments were done at the Agric. Botany Experimental Farm and Laboratory, Fac. of Agric., Mansoura Univ., Egypt during 2015/2016 and 2016/2017 seasons.

Methodology: The factorial combinations of three zeolite concentrations (0, 4, 8 g/kg) as a soil additive and three chitosan foliar applications (0, 250 and 500 mg/l) and three salinity levels (0, 50, 100 mM NaCl) were considered.

Results: Shoot and root length, branches number, shoot and root dry weight were declined as a result of salinity. Similarly, the concentrations of photosynthetic pigments, minerals, and essential oil yield were decreased, whereas Na+ and Cl- increased in each season.

Application of chitosan or zeolite counteracted the depressing effects of salinity on plant growth, photosynthetic pigments, oil %, and minerals. They declined sodium and chloride concentration in each shoot and root compared to untreated plants.

Conclusion: It could conclude that zeolite at 8 g/kg soil or chitosan at 250 mg/l, showed a uniform impact in alleviating of rosemary growth inhibition and its productivity under salinity stress condition.