| Abstrakt: |
Several pulse solutions were tested for their effectiveness in preventing leaf senescence on four cut oriental lily cultivars (Lilium sp. 'Acapulco', 'Kissproof', 'Noblesse' and 'Star Gazer'). Stems were pulsed 24 hours after harvest for I hour, stored in boxes in the dark for 5 days at 3 °C (37.4 °F) then evaluated in postharvest conditions. A new commercial product called Chrysal BVB, a proprietary mixture manufactured by Pokon & Chrysal (Miami) containing cytokinine and gibberellic acids, was the most effective product tested. Chrysal BVB [1 mL⋅L-1 (0.1%)] prevented leaf chlorosis and abscission on 'Acapulco' and 'Noblesse' and significantly reduced it by 82% on 'Star Gazer' and by 69% on 'Kissproof'. Stems pulsed in Fascination, a commercial mixture containing 1.8% gibberellins (GA4+7) and 1.8% benzyladenine [5.4 mg⋅L-1 (ppm) each], virtually prevented leaf chlorosis on 'Noblesse', reduced it by 50% or more on 'Acapulco' and 'Star Gazer', and significantly delayed it 8 days on 'Kissproof'. A 10 µM (2 ppm) pulse in thidiazuron, a substituted phenylurea with cytokinin-like properties, delayed leaf chlorosis on 'Star Gazer' but to a lesser extent compared to BVB and Fascination. Chrysal SVB, a proprietary mixture manufactured by Pokon & Chrysal containing gibberellic acid, had no effect on reducing leaf chlorosis on 'Star Gazer'. None of the pulse solutions had adverse effects on bud opening, flower quality or vase life. Maintaining stems in a bulb flower preservative significantly reduced leaf chlorosis and abscission in all cultivars when stems were not pretreated with a pulse solution or when a pulse solution was ineffective. [ABSTRACT FROM AUTHOR] |
