STUDY ON THE INFLUENCE OF THREE PRODUCTION METHODS ON BLUEBERRY PHOTOSYNTHESIS

The influence of three production methods (open-field, glasshouse, plastic house) on photosynthetic parameters of Vaccinium corymbosum ‘Bluecrop’ were compared, including net photosynthetic rate (Pn), stomatal conductance (Gs), and intercellular CO₂ concentration (Ci). For all production methods the diurnal curve for ‘Bluecrop’ Pn had two peaks and a midday depression of Pn. The minimum Gs under the three production methods occurred at 14:00 and the time of maximum Gs varied with production method. The maximum Gs for plants grown in an open-field occurred at 08:00 and 18:00 and the maximum Gs for plants grown in the glasshouse and plastic house occurred at 10:00 and 16:00. The Ci in plants in all production methods decreased between 06:00 and 10:00, remained low between 10:00 and 16:00, and increased after 16:00. The decline in Pn between 10:00 and 14:00 contributed to stomatal-limitation, while there was no stomatal limitation to Pn at any other time during the day.