Effect of municipal solid waste compost and gibberellic acid on morphological and physiological traits of tulip (Tulipa spp.) cv. Bright Parrot

Tulip is one of the most important potted and cut flowers in the world. It is a monocothiledone plant, belongs to the Liliaceae family. In this study, the effects of municipal solid waste compost (MSWC) in four levels (0, 10, 20 and 30%) and gibberellic acid in three levels (GA3) (0, 50 and 100 mgl-1) on flowering time and quality of early flowering tulips were evaluated. The research was done based on a completely randomized block design (RCBD) with three replications. In this experiment, bulbs sprouting time, leaves number, flowers number, stem length, flower diameter, flowering time, bulbs number, chlorophyll and carotenoid levels of the plant were measured. Results showed that in most traits, MSWC 10% and peat were more suitable than the other treatments. MSWC 30% delayed flowering time about 7 days. The most flowers and bulbs number were obtained in the plants treated with 100 mgl-1 GA3. Treatments containing MSWC 10 and 20% provoked the highest amount of chlorophyll in leaves. Also, high amount of MSWC caused soil salinity and decreasing the vegetative and reproductive growth in the plants.