Effect of Deficit Irrigation on Lemon Water Requirements and Yield in the Jordan Valley

In countries with limited water resources like Jordan; deficit irrigation (DI) could be used as a strategy to manage water more efficiently without significant yield reduction. This research was conducted in the Jordan Valley to assess the impact of two DI levels on lemon water requirements and productivity. The study was conducted for three consecutive years (2005, 2006 and 2007) on full-grown lemon trees using three irrigation treatments: T1 represents 100% of crop evapotranspiration (ET); T2 for 75% of T1; and T3 for only 50% of T1. The root zone depletion analysis showed that lemon trees in T3 were under water stress from early June to harvest and from mid of June to end of October for T2 in the three years, whereas no water stress occurred for T1 in the different years. The yield for the 75% treatment was 26.8, 17.8 and 22.0 tons/hectares for the three years, respectively. The water saving for T2 and T3 was 18-19 and 37-39%, respectively. Improved but not significant water use efficiency and economic water productivity were observed for T2 and T3 in the three years. The implementation of the 75% DI would be recommended to save water while sustaining the yield. The results of this research could be scaled up to demonstration level, and further be disseminated to the citrus growers’ community in the Jordan Valley