Effect of Cycocel and Daminozide on Vegetative Growth, Flowering and the Content of Essence of Pot Marigold (Calendula officinalis)

Pot marigold (calendula officinalis l.) is a medicinal and ornamentalplant. the effect of different concentrations of chlormequat (cycocel), anddaminozide, two plant growth retardant, on plant height, flowering, thecontent of essence and some other traits in pot marigold (calendulaofficinalis) was assessed. plant growth retardants are commonly applied tolimit stem elongation and produce a more compact plant. the experimentwas done as a factorial in randomized completely blocks design (r.c.b.d.)with 16 treatments and 3 replications in rasht. cycocel at 4 concentrations(0, 500, 1000 and 1500 mg/l) and daminozide at 4 concentrations (0, 1500,3000 and 4500 mg/l) were used. investigated characteristics were plantheight, leaf number, flower number, flowering time, fresh weight, drymatter, the content of essence and carotenoid in flowers. based on analysisof variance (anova), the effect of different treatments and their interactionon most traits was significant at 0.05 level of probability. the minimumheight (24 cm/plant) in treatment of 500 mg/l cycocel + 3000 mg/ldaminozide, the largest number of flowers (4.66 flowers/plant) in treatmentof 1000 mg/l cycocel + 4500 mg/l daminozide and most essence content(0.154 mg/100 g) in treatment of 4500 mg/l daminozide without cycocelwere obtained.