EFFECT OF THERMAL FORCING OF CORMS ON THE FLOWERING OF SAFFRON (CROCUS SATIVUS L.)

Abstract

Among all environmental factors, the temperature is considered one of the key elements that control the growth and development of saffron. This study was undertaken to investigate the effect of thermal forcing of corms on saffron growth and development. To this end, mother corms were collected at four different periods: late March (T2) , mid-April (T3) , late April (T4), and after leaf senescence (Control, T1) . The corms of each period were then pretreated at three successive temperature levels: at 25 °C for 2 weeks, at 15 °C for 2 weeks and finally at 4 °C for 12 weeks. The results showed that the thermal pretreatment of corms had a significant effect on some saffron parameters. The flowers of the corms that underwent thermal treatment were later than those of the control. Similarly, the flower numbers and stigma yield were negatively affected by thermal forcing of corms. Overall, the thermal forcing of corms under the proposed regime was unfavorable for the growth and development of saffron.