عنوان مقاله [English]
Agriculture as the largest water consumer for its efficient water use requires an appropriate irrigation scheduling. For an optimum irrigation the amount of potential evapotranspiration is needed. The aim of this study was to measure potential evapotranspiration and single and dual crop coefficients of saffron in the agricultural research farm of Shiraz University located in Bajgah area for third and forth years of Saffron crop life cycle. This experiment was conducted using three water balance lysimeters. According to lysimetric measurements, total potential evapotranspiration were 726 and 783 mm for the third and fourth year, respectively. Maximum potential evapotranspiration rate was 6.28 and 6.4 mm day-1 for the third year and fourth year, respectively. Different growth stages length of saffron for the third and fourth year were 30, 55, 55 and 65 days. The single crop coefficient for the initial, middle and the final growth stages for the third and fourth years were estimated 0.46, 1.2 and 0.35; 0.49, 1.25 and 0.35, respectively. Similarly, basal crop coefficients for three stages of the third and fourth year were 0.15, 0.9 0.17 and 0.15, 0.95 and 0.18, respectively.