THE WATER RELATIONS AND IRRIGATION REQUIREMENTS OF COCOA (THEOBROMA CACAO L.): A REVIEW

摘要: The results of research into the water relations cocoa are reviewed in context drought mitigation and irrigation need. Background information on centres production tree, role crop development growth processes, is followed by reviews effects stress stomatal conductance, leaf status gas exchange, together with tolerance, use productivity. Leaf shoot occur a series flushes, which synchronized start rains following dry season (or an increase temperature), alternating periods ‘dormancy’. Flowering inhibited but synchronous flowering occurs soon after ends. Roots too grow rhythmic pattern similar to that flushes. can reach depths 1.5–2.0 m, mass roots top 0.2–0.4 spread laterally >5 m from stem. Stomata open low light intensities remain fully full sunlight well-watered plants. Partial closure begins at potential about −1.5 MPa. Stomatal conductance sensitive air, declining as saturation deficit increases 1.0 up 3.5 kPa. Net photosynthesis transpiration both consequently decline over range values. Little has been published actual field. Measured ETc values equate <2 mm d−1 only, whereas computed rates 3–6 have also reported. Despite its sensitivity stress, there paucity reliable, field-based data practical value yield responses or irrigation. With threat climate change leading less, more erratic, rainfall tropics, uncertainty forecasting result will increase. Social, technical economic issues influencing agenda discussed.