Effect of Irrigation Interval and Two Irrigation Methods on Growth Indexes of Rosmarinus officinalis L.

Using proper irrigation management leads to optimum utilization of water, soil, and fertilizer and production of high yield and quality products. In order to investigate the effect of irrigation intervals and surface and subsurface drip irrigation systems on growth indicators of Rosmarinus officinalis L., a field experiment was carried out during 2015 growing seasons at an experimental farm in Kerman city. The treatments were laid out in split plot using a Randomized Complete Block Design with three replications. The treatments comprised three irrigation levels (I 1 =25, I 2 =40 and I 3 =55 mm evaporation from class A pan) in the main plots, and two drip irrigation systems (surface and subsurface) in the sub plots. The results showed that I 2 in comparison with I1treatment led to 44 mm water saving. However, dry weight, height of plants, number of shoots per plant and leaf area index decreased by 12.9%, 12.6%, 13.6% and 5.3 percent, respectively, while water use efficiency increased 3.6 percent. Also, results showed that water use efficiency, dry weight, height of plants, number of shoots per plant, and leaf area index increased by, respectively, 15.1%, 18.3%, 9.7%, 12.5% and 15 percent in subsurface drip irrigation compared to surface method. Therefore, for Rosmarinus officinalis L. cultivation in Kerman area, application of I 2 in subsurface drip irrigation system is the best way to increase the water use efficiency for the drought years.