Determination of water requirement of Rosa damascene Mill. using lysimeter

In order to investigate of water requirement in Rosa damascene Mill., an experiment was carried out in the Alborz Research Center in 2012. The lysimeters with drainage system were used for Rosa damascene (adult plant), Medicago sativa (reference plant) and control group (only soil). For each lysimeter, the soil moisture content was measured by weighting method before and after applying irrigation treatments based on the field capacity. The amount of water requirement and run-off were measured in each lysimeter. The evapotranspiration of Rosa damascene (ETc) and reference plant (ETo) was estimated by lysimeter. The plant coefficient of Rosa damascene (Kc) was calculated by ETc/ETo ratio. In order to comparison of lysimeter data with indirect methods, the Blaney Criddle and Penman-Monteith methods (corrected by FAO) were used to determine the evapotranspiration in reference plant. According to the obtained results, WUE and ETo in Rosa damascene were calculated to be 2.18 and 46.0, respectively. The evapotarnspiration of Rosa damascene after 820 GDD in full flowering, was 111 mm. The ETc after 3740 GDD in the late stage was estimated to be 1147 mm. The evapotarnspiration of reference plants, after 3833 GDD, in lysimeter, Blaney Criddle and Penman-Monteith methods were 1247, 1392 and 1160 mm, respectively. Based on results, a similar estimation of ETo content was obtained by lysimetr and computational methods.