Physiological variations of green coconut tree irrigated with saline water

Abstract The use of saline water for irrigation purposes in spite of its limitations, is becoming an alternative, for the farmers of different semi-arid regions of the world, including the Northeast Brazil. In this regard an experiment was conducted, during 2 years, with the objective of evaluating the viability of the use of saline water for irrigating dwarf coconut tree, in the initial phase of production. A completely randomized block design consisting of 4 levels of water salinity (ECw = 0.1, 5.0, 10.0 and 15.0 dS m-1) was adopted with five replications. Was evidenced reduction stomatal conductance and reduction in water potential of leaves increasing salinity. Alteration in photosynthesis efficiency apparatus was not verified, due to salinity of irrigation water.摘要 尽管咸水灌溉存在固有局限性，但该方式已逐渐成为全球各半干旱地区（包括巴西东北部）农户的替代灌溉选择。为此，本研究开展了为期2年的试验，旨在评估咸水用于矮椰子树生产初期灌溉的应用可行性。试验采用完全随机区组设计，设置4个水盐度梯度（ECw=0.1、5.0、10.0和15.0 dS·m⁻¹），每组设置5次重复。研究结果表明：随着灌溉水盐度升高，植株气孔导度与叶片水势均出现显著降低；但未观测到灌溉水盐度对光合机构的效率产生显著影响。