S. Soroori - Department of Horticultural Sciences, Aliabad Katoul Branch, Islamic Azad University, Aliabad katoul, Islamic Republic of Iran.
E. Danaee - Department of Horticultural Sciences, Garmsar Branch, Islamic Azad University, Garmsar, Islamic Republic of Iran.
Kh. Hemmati - Department of Horticulture Sciences, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Islamic Republic of Iran.
A. R. Ladan Moghadam - Department of Horticultural Sciences, Garmsar Branch, Islamic Azad University, Garmsar, Islamic Republic of Iran.

The first experiment was performed to study the effect of foliar application of spermidine, citric acid and proline (۰, ۵۰ and ۱۰۰ mg L-۱) on some metabolites and enzymatic activities of Calendula officinalis L. under drought stress (No stress: Control, ۲۵, ۵۰, and ۷۵% field capacity). The second experiment was performed to study the effect of foliar application of spermidine, citric acid and proline (۰, ۵۰ and ۱۰۰ mg L-۱) on the post-harvest shelf life of flowers (beginning of the experiment, ۵, and ۱۰ days post-harvest). The experiments were factorial in a completely randomized design with ۳ replications. All treatments had a significant effect on the measured variables. In the first experiment, FC ۲۵% reduced all traits, FC ۷۵% increased carotenoid, carbohydrate, phenol, flavonoid, protein, Peroxidase (POD) and Superoxide Dismutase (SOD) activities. The highest vitamin C was observed in the control FC. Also, foliar application of ۱۰۰ mg L-۱ proline, increased carotenoid, carbohydrate and phenol, ۵۰ mg L-۱ proline increased protein content. Also, ۱۰۰ mg L-۱ of spermidine increased flavonoid and ۱۰۰ mg L-۱ of citric acid increased vitamin C, SOD and POD activities. In the second experiment, all evaluated traits were reduced ten days after harvest, the highest post-harvest life was for ۱۰۰ mg L-۱ of citric acid (۹.۷ days) and the lowest was for the control (۵.۳ days). The study results showed that application of ۱۰۰ mg L-۱ spermidine, citric acid and proline with FC ۷۵% improved biochemical properties, nutritional traits, and post-harvest life of Pot marigold.

Medicinal and ornamental plants, Pot marigold, Shelf life.