Mepiquat chloride in red sunflower cultivation as flower vase

The objective was to evaluate the effect of mepiquat chloride in red sunflower cultivation as flower vase. A completely randomized design was adopted with ten repetitions and five concentrations of mepiquat chloride (250; 500; 750; 1000 and 1250 mg L-1), was used as a control sprayed plants with only distilled water. The applications were performed at 15; 30 and 45 days after sowing. We evaluated the plant height parameters (PG), stem diameter (SD), internal diameter of the main inflorescence(IDMI), number of leaves (NL) and inflorescences (NI), dry mass of leaves (DML), mass dry stem (MDS), dry mass of inflorescence(DMI) and root dry weight (RDW), leaf area (LA), contents of chlorophyll a, b and carotenoid. Increasing the concentration of mepiquat chloride reduced the PG, IDMC, MDS, DMC, RDW and LA, but increased the SD values, DML, chlorophyll a, b and carotenoids. The NL and MSF did not significantly change the application of growth reducer. The application of mepiquat chloride increased the number of inflorescences per plant and reduced height sunflower cv. Sol Vermelho, but these reductions were not enough to obtain plants suitable for marketing in pots.