Response of seed·propagated geranium (Pelargonium x hortorum L. H. Bailey) to application of flurprimidol

Abstract

In 1998 and 1999 flurprimidol spray applications to seed-propagated geranium (Pelargonium x hortorum L.H.Bailey) cultivars were made to evaluate efficacy and identify optimum concentration of flurprimidol. Growth retardant was applied as a single spray at O, 7,5, 15 and 22,5 mg L^-1, when plants were 9-13 cm in height. The response of plants to flurprimidol application varied depending on geranium cultivar. At the time of flowering the plants sprayed with flurprimidol at concentrations of 7,5, 15 and 22,5 mg L^-1 were significantly shorter than the untreated ones. The plant diameter, floret diameter, floret peduncle length and inflorescence diameter of geranium treated with flurprimidol were significantly smaller than those of the control plants. Flurprimidol hastened flowering of geranium cultivars 'Suzan Improved', 'Pinto Salmon' and 'Ringo 2000 Violet' by 5-8 days in 1999 but had no significant effect on days to flowering in 1998. The chemical name used: a-(1-methylethyl)-a-[4-(trifluoromethyloxy)-phenyl]-5-pyrimidine-methanol (flurprimidol).