Effects of Seed Coating with Plant Growth Regulators on Seed Germination and Seedling Growth of Sugar beet (Beta vulgaris)

This study was carried out to evaluate the effect of sugar beet seed coating with plant growth regulators on germination and seedling growth characteristics. The experiment was conducted as factorial in a completely randomized design with three replications. Nine seed treatments or coating with various amounts of growth regulators along with a control treatment (no cover-up) were applied on two sugar beet hybrid varieties (Shekofa and Pars). The sugar beet hybrid seeds were coated with various amounts of growth regulators, including 100cc solution of gibberellic acid with concentrations of 0.04, 0.08 and 0.12%(w/v), 100cc solution of salicylic acid with concentrations of 0.06, 0.12 and 0.18% (w/v), and 100cc solution of ethylene with concentrations of 0.2, 0.4 and 0.6% (v/v). The results showed that sugar beet seed coating with 100cc solution of ethylene with concentrations of 0.6, 0.4 and 0.2% (v/v), respectively improved germination rate, so that the time required to reach 10 and 90% germination was lower. Whereas seed treatment with gibberellic acid caused a significant reduction in seed germination and increased the time required to reach 10 and 90% germination. The root dry weight of Pars was significantly higher than Shekofa. Among the different seed treatments or coatings, treatments of gibberellic acid 0.08 and 0.12%(w/v) and treatment of ethylene 0.2% (v/v) had the highest root dry weight than the other treatments, and the root dry weight in the second and third gibberellic acid seed treatments was increased by 49.6 and 49%, respectively as compared to control.