Effect of seed coating and pelleting with plant growth promoting rihzobacteria on germination and seedling growth of sugar beet (Beta vulgaris)

In this study, the efficiency of two seed coating methods including coating and pelleting and 12 bacteria levels including control, Azotobacter, Bacillus, Pseudomonas, Azospirillum, combination of two bacteria, and combination of all bacteria with 1-CFU ml 107 concentration was evaluated on germination, seedling growth, and bacterial survival on seed coat after 6 months in sugar beet cultivar Pars. The experiment was conducted in a factorial arrangement based on a randomized complete block design with four replications in 2015. Results showed significant effect of bacteria on seedling fresh weight, normal seedling percentage, and seed vigor; however, the two coating methods had no significant effect on the above-mentioned traits. Seed coating with Pseudomonas resulted in 160, 50, 128 and 90% increase in seedling fresh weigh, normal seedling percentage, and seed vigor compared with control. The effect of Pseudomonas and Azotobacter combination was also positive. Bacterial survival after 6 months was higher in pelleted seeds than coated seeds. The Bacillus, Pseudomonas, Azospirillum and Azotobacter population concentration on coated seeds were 25000, 15950, 0 and 14100 CFU, respectively.