CLIMATE CONTROL FOR BOOSTING CO2 UPTAKE IN CAM ACTIVE SHORT DAY PLANTS BY SHIFTING TO LONG DAY CONDITIONS AFTER FLOWER INITIATION
CAM active short day plants as e.g., Kalanchoë, induce flowers after a specific short day period, usually controlled with light and black-out screens. Day length is commonly controlled with a long day treatment as start up cultivation, followed by a prolonged short day period for flower induction. Kalanchoë changes from young plants with C3 to older plants with CAM metabolism. As the diurnal dynamics of CAM can be divided in four stages with I Malic acid accumulation, II Morning transition, III Malate decarboxylation, and IV Evening transition; phases I-III can be shortened, which results in faster growth and using and increased phase IV. In this case climate control with optimized light, CO2 and temperature control can be used to maximize crop growth. For creating a climate control concept, experiments were performed. Data show that especially CO2 uptake during the light period is affected by day length, both in C3 (4 weeks) and CAM (11 weeks) active plants, whereas CO2 uptake of CAM active plants and respiration in C3 active plants are only affected to minor extend during the dark period. Total CO2 uptake is increased by approx. 25% when increasing the day length by 5 hours, i.e., decreasing phase I-III and increasing phase IV. Based on that a new climate control regime for Kalanchoë was developed, also taking fluctuations electricity spot-prices into account.
Körner, O. and Nielsen, K.L. (2014). CLIMATE CONTROL FOR BOOSTING CO2 UPTAKE IN CAM ACTIVE SHORT DAY PLANTS BY SHIFTING TO LONG DAY CONDITIONS AFTER FLOWER INITIATION. Acta Hortic. 1037, 587-592
CAM, CO2-uptake, DSS, model, simulation, software