Study of Effects of Root Temperature, Corm Size, and Gibberellin on Underground Organs of Saffron (Crocus sativus L.)

In this investigation, effects of root temperature, corm size and gibberellin on underground organs of saffron were studied, in a growth chamber, by using a split-plot factorial design. Three levels of temperatures (10, 15 and 20 degree Centigrade) were applied as main plots. Subplots were a factorial combination of corm size (with two levels large and small), and corm treatment with gibberellin (with two levels 0 or 500 ppm of gibberellin). The results showed that large corms, which were treated with gibberellin and grown in 15°C or 20°C, had more root number, fresh and dry weight than the other corms. Large corms, which were grown in 10°C, had maximum active bud number and daughter corm. Minimum active bud number was detected on corms, which were treated with gibberellin. Higher dry weight of daughter corm was produced by large corms, which were grown in 10°C, and treated with gibberellin. Therefore, 15°C or 20°C during the beginning stages of growth and 10°C at the end stage of growth can improve size and number of daughter corm of saffron.