عنوان مقاله [English]
Saffron (Crocus sativus L.) as the most important medicinal and agricultural crop of the world has therapeutic properties including laxative, stomach stimulant, anti cancer, anti inflammation and against spasm. One of the reasons of lower yield in traditional farms of Iran is using small corms of old farms. Combining the date of corm lifting and the duration of 25°C incubation, corms could be flowered from early September to mid-December. The results showed that corm weight of saffron affects significantly on flowering and yield. Soils covered by mulch or surface mulch compared with soils lack of mulch have a higher thermal adjustment so that in higher ambient temperature the soil can be warm later and at night they lose their warmth later. This research was conducted to find the effects of corm weight, planting beds under hydroponics at commercial level and determination of the best time of corm lifting from farm and its transfer for production and their interaction under controlled conditions on yield and other characters of this precious crop.
Material and Methods
In order to study effects of corm weight and time of its lifting from farm in planting beds an experiment was conducted as factorial in the form of RCBD in three replicates at the agric. Research complex of Fadak and Research Institute of Food Science and Technology (RIFST) in 2010. Factors under study were: two corm weights (8 to 10 and more than 10 g), two planting beds (stone wool and peat moss) and six lifting times (mid June, early July, mid July, early August , mid August and early October). For 40 days, 457 corms per m-2 were stored in incubation with 85% relative humidity and 25°C temperature at the darkness. Then, saffron corms were transferred in growth chamber with 17° C in 8/16 h light and dark. Characteristics such as number of flower, fresh weight of flower, dry weight of flower, fresh and dry weight of stigma, fresh and dry weight of style, fresh and dry weight of stigma+style and Picrocrocin, Safronal and Crocin contents of saffron were measured. Statistical analysis of data was conducted by SAS 9.1 and mean comparisons by Duncan’s multiple range test at 5%.
Results and Discussion
Results showed that the corm weight, bed type and time of corm lifting were significant effects on economical yield of saffron such as picked flowers, dry weight of stigma and fresh weight of flowers. The highest saffron economical yield was obtained in interaction of corm weight, 10 g, peat moss and lifting time in mid June as much as 5.2 g.m-2. This yield is 11 fold of average yield of Iranian forms. Growth period of all treatments was in the limit of 115 to 120 days from the time of lifting corms from the soil up to end of flowering except to the treatment corm in the late august with respect to the waiting time of 30 days in the room of flower formation was not able to flower. Incubation period of all treatments was determined as 90 days. Picrocrocin, Safranal ad Crocin contents in peat moss under controlled conditions was graded as excellent thread compared with National Standard of 259-2. Results obtained are corresponded with other researchers.
It is concluded that the highest saffron economical yield was obtained in interaction of corm weight, 10 g, peat moss and lifting time in mid June as much as 5.2 g.m-2 that is recommended to farmers to apply to increase saffron yield under controlled conditions as much as possible. It seems that time of lifting corms from the soil in addition to effect of temperature through moisture availability, has affected on flowering period of saffron.