Effects of Temperature and Gibberellic Acid on Forcing and Quality Improvement of Iris (Iris hollandica cv.  Blue Magic') Cut Flowers

In order to accelerate forcing, reduce the production period and to extend the vase life of Iris hollandica cv. ‘Blue Magic’ cut flowers, an experiment was performed in the research glasshouse of the Faculty of Agricultural Sciences, University of Guilan, Rasht, Iran, in 2007. The experiment was carried out as factorial based on completely randomized design with three replications. Factors were temperature (5, 10 and 15C) and gibberellic acid (0, 300 and 600mg/l). The concentration of 600mg/l gibberellic acid at 5C accelerated sprourting and flower appearance and increased stem length, vase life of cut flowers and percentage of total soluble solid of petals as compared to other treatments. Furthermore, treating cut flowers with 600 mg/l gibberellic acid significantly increased the anthocyanin of petals and chlorophyll content of leaves. Also, reducing the temperature to 5ºC significantly increased the anthocyanin of petals.