Effect of postharvest treatments on the longevity of cut inflorescences of ‘Rialto’ oriental lily

Cut lily flowers are very popular but their longevity is not satisfactory. The quality of cut lily flowers is determined by two factors: the longevity of the flowers and the general appearance of the entire cut stem during its vase life. The aim of this work was to evaluate the effects of gibberellic acid (GA₃), standard preservative (8HQC and 2% sucrose) and commercial preservatives Chrysal Professional 2 and Chrysal sachet as well as Floralife 200 and Floralife 300 on the quality of ‘Rialto’ cut oriental lily, a white blooming cultivar very popular on the Polish market. The contents of reducing sugars, soluble proteins, free amino acids and free proline were also determined in the senescing flowers. As a major problem in the postharvest handling of lilies is leaf yellowing, the effects of postharvest treatments on the quality of leaves and their chlorophyll contents were also studied. Conditioning (24 h) with GA₃ (500 mg d.m.⁻³) immediately after harvest delayed chlorophyll loss in leaves. When combined with the standard preservative and commercial preparations Chrysal Professional 2 and Chrysal sachet as well as Floralife 200 and Floralife 300, GA₃ prolonged flower vase life. The most effective method was using GA₃ and Floralife products, which prolonged the vase life of flowers to 23 days, 43% longer relative to the untreated flowers, and maintained the decorative value of the leaves (53 days). During the senescence of flowers held in water, the contents of reducing sugars, free amino acids and proline increased. However, the holding solutions modified changes in these parameters relative to the control.