Effects of seed priming and foliar application of salicylic acid on yield and essence of fennel (Foeniculum vulgare Mill.) under drought stress condition

To study the effects of seed priming and foliar application of salicylic acid (SA) on yield and essence of fennel (Foeniculum vulgar Mill.) under drought stress condition, a field experiment was conducted at College of Agriculture, University of Zanjan in the spring of 2012. The experiment was conducted as a split plot based on complete randomized block design with three replications. In this study, drought stress at reproductive stage with control (full irrigation) was assigned to the main plots and different treatments of seed priming and foliar application with SA including dry seeds (without priming), seeds priming with SA at different concentrations (0, 800 and 1600μmol) and foliar application with SA at different concentrations (800 and 1600μmol) were assigned to the subplots. Results showed that the majority of measured traits including number of umbrella in plant, number of seeds in umbrella, seed thousand weight, harvest index, biomass, grain yield, and essential oil yield significantly decreased under drought stress condition and the essential oil content increased vice versa. Therefore, the highest seed (2925.6kg/ha) and essential oil yield (52.88kg/ha) were obtained in control, and the lowest amount of mentioned traits was obtained in drought stress condition. The results also showed that the effect of seed priming and foliar application of SA on the majority of measured traits was significant. There were no differences about seed yield and essential oil yield between foliar application and priming with SA at a concentration of 1600 μmol; however, the highest seed yield (2579.60kg/ha) and essential oil yield (63.15kg/ha) were obtained in foliar application with SA at a concentration of 1600μmol, and the lowest amounts of mentioned traits were obtained in dry seeds (without priming).