The Effect of Azotobacter On Growth Indices, Yield and Essence Content of Two Cultivars of Cumin (Cuminum cyminum L.) Under Salinity

In order to investigate the effect of azotobacter on growth indices,grain yield and essence content of two cultivars of cumin (Cuminum cyminum L.) under saline conditions, an experiment was carried out in a factorial design arranged as randomized complete block with three replications in 2015 at Kashan University, Iran. Two cumin local varieties including Ardestān and Mashhad Ardehal were used. In a rudimentary experiment, the tolerance threshold was at 150 and 250 mM of Sodium Chloride for both varieties. The result showed that salinity and inoculation with bacteria had a significant effect on the percentage and germination rate, root length, plant height, and seed vigor. Increased concentrations up to 250 mM molar sodium chloride resulted in a significant reduction in germination percentage and germination rate, root length, stem height, seed vigor, grain yield and essence yield. Also, the results presented that in both varieties and at all levels of salinity,inoculation with bacteria compared to the control, lead to a significant increase in chlorophyll (a, b), carotenoids, catalase, ascorbate peroxidase, plant height, grain yield and essence yield. Overall, Ardestan variety showed higher values for plant height, Chlorophyll (a, b), the carotenoids, catalase, ascorbate peroxidase and essence content compared to Mashhad Ardehal variety. In general, the result of this experiment can be used to decrease salinity effects by azotobacter inoculation and increase grain yield and essence content of cumin.