Comparative gas exchange characteristics of potted, glasshouse-grown almond, apple, fig, grape, olive, peach and Asian pear

Net photosynthesis (P_n), dark respiration (R_d), transpirational flux density (TFD) and leaf conductance (k_l) on glasshouse-grown plants of almond, apple, fig, grape, olive, peach and Asian pear were examined under various laboratory environmental conditions. Grape and almond had the highest light-saturated photosynthetic rates, greater than 20 μmol CO₂ m⁻² s⁻¹. Apple had the lowest temperature optimum for P_n, 20°C. Almond had the highest R_d rate between 10 and 50°C, but grape had the highest Q₁₀ for respiration, a value of 2.5. Apple, olive and grape stomata were most sensitive to the leaf-to-air vapor pressure difference. Apple had the greatest sensitivity of P_n to the vapor pressure difference.