The effect of growth retardants on growth and flowering of dwarf alstroemeria

Abstract

The experiment was conducted to inhibit the growth of dwarf alstroemeria cultivars 'Rosalina' and 'Dorotea' using flurprimidol and daminozide. Additionally, the effect of these retardants on days to anthesis, flowering shoots number, diameter and longevity of florets was evaluated. In vitro propagated plants, grown in 12 cm pots were treated with single sprays of flurprimidol (7,5, 15, 22,5 mg l^-1) and daminozide (2500, 3500, 4500 mg 1^-1) following second pruning, when shoots were 9-12 cm long. Well retarded plants of both dwarf alstroemeria cultivars were obtained when plants were sprayed with flurprimidol at 22.5 mg 1^-1. Plants treated with daminozide at all tested concentrations were to tall to be grown in 12 cm pots. Flurprimidol significantly reduced the canopy diameter, number of flowering shoots of alstroemeria cultivars 'Rosalina' and 'Dorotea' and floret size of cultivar 'Rosalina'. Daminozide had no effect on the number of days to flower but flurprimidol delayed flowering of tested cultivars only at concentration of22.5 mg 1^-1. Intensified green leaf colour was observed on flurprimidol treated plants. The chemical names used: a-(1-methylethyl)-a-[4-(trifluoromethyloxy)-phenyl]-5-pyrimidine-methanol (flurprimidol), butanedioic acid mono (2,2-dimethylhydrazide) (daminozide).