تاثیر تیمارهای خراش دهی پوسته بذر و سرمادهی بر جوانه زنی چای ترش

Rosell (Hibiscus sabdariffa) seed is dormant and it germinates poor and slow. An experiment was conducted to investigate the effect of gibberellic acid, potassium nitrate, chilling and scarification on germination of two landraces of rosell as completely randomized design with four replications. The treatments included two levels of gibberellic acid, two levels of potassium nitrate, three levels of chilling, mechanical scarification and three levels of chemical scarification. The results showed that the germination of both landraces treated with gibberellic acid, potassium nitrate and chilling significantly increased, but the seed scarification had no significant effect on seed germination. Therefore poor germination in rosell associated with endogenous dormancy. With regard to positive effects of gibberellic acid, potassium nitrate and chilling and considering toxicity and costs of chemicals, these results suggested that chilling treatment is the best technique for increases germination of rosell.