High temperature promotes growth and flowering in Sophrolaeliocattleya

This study investigated the effects of temperature on vegetative growth and flowering in Sophrolaeliocattleya 'Red Doll' and 'Grace'. Plants were grown at constant temperatures of 8, 13, 18, or 23A degrees C for 12 weeks in environmentally controlled growth chambers. Photosynthetic efficiency was measured four weeks after the start of the temperature treatment. The shoot length, leaf length, leaf width, and the number of new shoots increased in plants from both cultivars that were grown at 18 and 23A degrees C, respectively; whereas the number of days to visible buds and flowering were reduced compared to plants grown at 8 and 13A degrees C. The number of flowering florets and the flower diameter were greater in plants grown at 18 and 23A degrees C than at 8 and 13A degrees C. High photosynthetic efficiency was observed in plants grown at 23A degrees C, which was measured as increased PSII quantum yield, photochemical quenching, and electron transport rate; and decreased non-photochemical quenching. These results indicate that temperatures of 18-23A degrees C promote growth and stimulate earlier production of high-quality flowers in Sophrolaeliocattleya.