Comparison of bubbler, sprinkler and basin irrigation for date palms (Phoenix dactylifera, cv. Zahdi) growth in Kish Island, Iran

This project was conducted to investigate the response of date palm (Phoenix dactylifera, cv. Zahdi) growth to three different irrigation methods: basin, bubbler and sprinkler irrigation systems under Kish Island climatic conditions during five successive years (2000-2004). This date planting comprised of 86 relatively uniform 10 year-old date-palms, which were cleaned, trimmed and standard fertilized regularly, but they have not been pollinated artificially during experiment. The results of this project demonstrated that the mean values of leaf number, leaf size, tree height and leaf mineral content of date palm were significantly (P = 0.05) influenced by irrigation systems. As expressed in greater annual leaf number and tree height the general trend of growth increased as water availability to tree increased. The maximum vegetative growth (the mean height, leaf number and leaf size) was produced from palm trees irrigated with the bubbler irrigation system during five years, followed by the basin method. Bubbler irrigation was superior to basin and sprinkler irrigation, due to less evaporation and higher water availability to plants. Mineral contents of the leaves were also influenced by irrigation system. An increase in N content of leaves, with some between-year variations in relative values, was found and a fairly uniform N content in leaves of the bubbler-irrigated dates. P2O4 content did not significantly change in the treatments during the three years of analyses. Similarly, K content varied annually (non-significantly) between treatments. Date palm trees could be grown and also takeup minerals when only a small part of the area between trees was irrigated. The advantage of using bubbler irrigation under marginal conditions of saline water, soil stress and atmospheric dryness, the conditions under which the experiment was carried out, is discussed.