A two-year study (2005 - 2006) was carried out to explore the effect of deficit irrigation treatments according to evaporation from a class A basin, including ET= 1 (T1), ET = 0.75 (T2), and ET = 0.5 (T3), on yield, yield components and seed yield of three varieties of watermelon (Charleston Gray, Sugar Baby and Crimson Suite) in the Varamin Agricultural Research Center of Iran. A randomized co...