VII International Symposium on Protected Cultivation in Mild Winter Climates: Production, Pest Management and Global Competition edition:7 location:Kissimmee, Florida, USA date:23-27 March 2004
Most commercial bromeliads originate from the American tropics and subtropics. In Europe ornamental bromeliads are cultivated in heated greenhouses. The effects of (sub)optimal temperatures were tested on Aechmea fasciata, A. chantinii, Vriesea ‘Christiane’ and V. philippo-coburgii. During the winter period in Belgium two temperature regimes (minimum temperature) were used; i.e. NTR: day 21°C and night 19.5°C, CTR: day 15°C and night 12°C. Growth of both Aechmea’s was reduced when they were cultivated in colder conditions. The relative electrolyte leakage (REL) of the leaf tissue was determined in order to locate potential cell membrane damage. Aechmea’s cultivated at 15/12°C had higher REL values than their counterparts cultivated at 21/19.5°C. The turgor pressure of leaf cells from Aechmea’s grown at 15°C/12°C was negative. This indicated plasmolysis of the leaf cells. The studied Vriesea’s suffered less from these colder cultivation temperatures. They could also withstand more extreme cold temperatures (2°C), however frost (-4°C) was lethal. The better performance of the studied Vriesea’s could not be explained by an increased amount of sugars but was probably related with the superior condition of their cell membranes.