Influence of Salicylic Acid on Growth, Yield and Macro-elements Absorption of Fennel (Foeniculum vulgare Mill.) under Water Stress

The present study was conducted in order to investigate the effect of salicylic acid on growth, yield and macro-elements absorption of fennel in split-plot as base on randomized complete block design (RCBD) with three replications in Tehran, Iran. Irrigation regime as main plot was undergone in 5 levels that included: I1: full irrigation, I2: cut off irrigation at stem elongation stage, I3: cut off at budding stage, I4: cut off irrigation at 50% flowering stage and I5: cut off irrigation at grain filling stage. Foliar application of SA (0, 3, 6, and 8 mM) as sub plot was applied at stem elongation, budding and 50% flowering stages. Result indicated application of SA was resulted to increase biological yield in all irrigation regimes. However, application of 6 mM SA had the most biomass under water stress at grain filling stage. Interaction of water stress and SA demonstrated that application of 3 mM SA had the most grain yield under full irrigation, water stress at stemming and water stress at grain filling stages, while application of 9 mM SA had the highest grain yield under water stress at budding and 50% flowering stages.