EFFECT OF LEAF MATURITY, TEMPERATURE, CARBON DIOXIDE CONCENTRATION, AND LIGHT INTENSITY ON RATE OF PHOTOSYNTHESIS IN CLONAL LINES OF THE LOWBUSH BLUEBERRY, VACCINIUM ANGUSTIFOLIUM AIT. UNDER LABORATORY CONDITIONS

Abstract

The rate of apparent photosynthesis of the lowbush blueberry was determined in Warburg flasks using Pardee's CO2buffers. A marked increase in rate of O2evolution occurred as the temperature was raised from 13.0 to 29.5 °C. With a constant temperature of 25.0 °C the rate of O2evolution increased as the CO2concentration increased from 0.2 to 0.8%. The young and middle-aged leaves had a higher rate of apparent photosynthesis than the older leaves. The rate was higher at a light intensity of 1000 ft-c than at 650 ft-c at a CO2concentration of 0.4%. At the higher light intensity a lowbush blueberry clone selected on the basis of superior agronomic characteristics had a significantly higher rate of apparent pholosynthesis than an average clone.