Table 2. Mean values for the photosynthetic and respiration parameters of coffee plants grown under shade or full sunlight conditions.
| Parameters | Treatments | |
| Shade | Full Sun | |
| A (µmol CO2 m–2 s–1) | 7.9±0.4 | 12.0±0.8* |
| gs (mmol H2O m–2 s–1) | 94±9 | 146±17* |
| g m_Harley (mmol CO2 m–2 s–1) | 76±4 | 116±10* |
| g m_Ethier (mmol CO2 m–2 s–1) | 65±12 | 109±5* |
| C i (µmol CO2 mol–1 air) | 247±11 | 246±7 |
| C c_Harley (µmol CO2 mol–1 air) | 143±10 | 142±9 |
| J F (µmol e− m–2 s–1) | 70±5 | 106±5* |
| V cmax_Ci (µmol CO2 m–2 s–1) | 26.8±1.6 | 42.1±2.2* |
| V cmax_Cc (µmol CO2 m–2 s–1) | 58.1±3.5 | 78.5±4.0* |
| J max_Ci (µmol e– CO2 m–2 s–1) | 71.1±4.4 | 109.5±3.1* |
| J max_Cc (µmol e– m–2 s–1) | 102.7±6.3 | 142.6±7.4* |
| J max/V cmax_Ci | 2.6±0.04 | 2.7±0.1 |
| J max/V cmax_Cc | 1.8±0.1 | 1.8±0.1 |
| C c_trans (µmol CO2 mol–1 air) | 228±17 | 249±23 |
| R D (µmol CO2 m–2 s–1) | 0.5±0.06 | 1.2±0.05* |
| R L (µmol CO2 m–2 s–1 | 0.1±0.05 | 0.3±0.08* |
| A/g s (µmol CO2 mol–1 H2O) | 86±6 | 84±4 |
| g m_Harley/g s (mol CO2 mol–1 CO2 ) | 1.4±0.1 | 1.3±0.1 |
| R p (µmol CO2 m–2 s–1) | 3.2±0.4 | 4.5±0.1* |
| Stomatal limitation | 0.41±0.04 | 0.38±0.02 |
| Mesophyll limitation | 0.30±0.02 | 0.30±0.01 |
| Biochemical limitation | 0.29±0.03 | 0.32±0.03 |
n = 6±SE. The overall photosynthetic limitations associated with stomatal, mesophyll and biochemical factors are also shown. Data for A, g s, g m_Harley, C i, C c_Harley, J F, and R P were obtained under PPFD of 1000 µmol m−2 s−1, C a of 400 µmol mol−1 and leaf temperature of 25°C. Asterisks indicate statistically significant differences (P<0.05) between shade and full sun treatments.
Abbreviations: A, net photosynthesis; g s, stomatal conductance to water vapour; g m, mesophyll conductance to CO2; C i, sub-stomatal CO2 concentration; C c, chloroplastic CO2 concentration; J F, electron transport rate estimated by chlorophyll fluorescence; V cmax, maximum carboxylation capacity; J max, maximum capacity for electron transport rate; C c_trans, the C c that denotes the transition between the Rubisco- and RuBP regeneration-limited state; R D, dark respiration; R L, light respiration; R P, photorespiration rate.