Effects of growing medium on some postharvest characteristics of cut flowers in six cultivars of Asiatic hybrid lilies (Lilium longiflorum L.)

The effects of different growing medium on the physiological status of postharvest cut flowers in six cultivars of Asiatic hybrid lilies were studied using a factorial experiment arranged in a completely randomized block design with three replications. The three variables used in the factorial experiment were 1) Asiatic hybrids of lilies (Amarone, Orlando, Pink Superior, Pollyanna, Salsa and Vignola), 2) chemical treatments including gibberellic acid (50 mg/l), 8-hydroxyquinoline sulphate (200 mg/l), 3% sucrose solution and distilled water as the control and 3) growing medium, i) 1/3 peat+1/3 perlite+1/3 garden soil and ii) 1/3 humus soil+1/3 sand+1/3 garden soil. Three replicates were used for each experimental group. Bulbs of lily hybrids were cultivated in a combination of the two growing media with one bulb in each pot in the greenhouse, College of Agricultural Science, University of Guilan. The number of floral buds, shoot length, flowering time and chlorophyll content of leaves were studied before harvest. The cut flowers were treated with chemicals for 24 h and then placed in distilled water at 20±1oC. The effects of different treatments on flower and leaf longevity, fresh weight of flowers and chlorophyll content of leaves were studied. Results obtained indicate that growing medium had no significant effects on the number of floral buds, flowering time and chlorophyll content of leaves. However, cultivating bed made up of peat and perlite increased shoot length significantly (P<0.01). The effect of hybrid cultivars on shoot length, number of floral buds, flowering time and chlorophyll content of leaves was significant (P<0.01). Among the chemicals used, gibberellic acid significantly increased flower and leaf longevity, fresh weight of flowers and chlorophyll content of leaves. Treatments with 8-hydroxyquinoline sulphate and sucrose increased flower longevity but resulted in decreased leaf longevity.