Postharvest quality of ornamental cuttings evaluated by chlorophyll fluorescence

Globalization of the ornamental industry leads to an increased import and export of young plants and cuttings. In the Belgian ornamental industry, there is an increasing trend of producing high quality cuttings in favourable climatic regions worldwide. Transport of these cuttings to the Belgian nurseries and worldwide can affect their quality. To assess postharvest quality after transport or storage, chlorophyll fluorescence was evaluated as a non-destructive method. Therefore, cuttings from two pot chrysanthemum (Chrysanthemum morifolium) cultivars, ‘Conaco’ and ‘Jasoda’, were stored in dark conditions at 3.1±0.3°C for 35 days. After 0, 5, 10, 15, 21, 28, and 35 days, cuttings were removed from the cold room and were rooted. Chlorophyll fluorescence was measured during the first days of rooting. Results show optimal levels of F_q’/F_m’ already 24 h after sticking for ‘Conaco’ for all storage treatments. ‘Jasoda’ showed suboptimal levels of F_q’/F_m’ 24 h after sticking for cuttings that were stored for at least 21 days. Two days after sticking, a suboptimal level of F_q’/F_m’ was still monitored for cuttings stored for 35 days. This was also reflected by visual leaf damage. It is concluded that below a certain threshold value for F_q’/F_m’, measured 24 h after sticking, the quality of rooted cuttings will be poor.