Influence of gibberellic acid on the physiology and flower quality of gerbera and lily cut flowers

Abstract

The objective of this study was to assess the influence of different foliar gibberellic acid (GA₃) levels (0, 10, 50, and 200 mg L^-1) and application timing on the growth, physiology (chlorophyll and gas exchange) and flower quality of gerbera (Gerbera jamesonii cvs. Beaudine and Palm Beach) and Asiatic lily (Lilium × elegans cvs. Fangio and Eldivo). The application of GA₃ (50 mg L^-1) increased (p < 0.05) gerbera shoot height (30%), pedicel length (20%), and vase life (12.5%) and decreased the number of days to flowering (7%) compared to the control. GA₃ application at the seedling stage increased pedicel length and flower diameter compared to GA₃ treatment at the flower initiation stage. However, the chlorophyll content index, photosynthesis (Pn), stomatal conductance (gs) and transpiration (E) were similar across the study period. For Asiatic lily, 10 and 50 mg L^-1 were the best GA₃ levels in terms of leaf gs, E and flower diameter. Compared to 0, 10 and 50 mg L^-1-GA₃, 200 mg L^-1-GA₃ decreased the number of days to flowering. Overall, the application of 50 mg L^-1-GA₃ to gerbera and lily cultivars at the seedling stage can potentially improve flower quality and shorten the number of days to flowering.