Growth retardants affect growth and flowering of Scaevola

The effects of concentration and method of application of uniconazole on gr owth and flowering of Scaevola aemula R. Br. 'New Wonder', 'Mini Pink Fan', 'Purple Fan', and 'Royal Fan', Scaevola albida (Sm.) Druce,'White Fan', an d Scaevola striata 'Colonial Fan' were studied, as was the efficacy of four other growth retardants on S, aemula 'New Wonder'. Variables measured incl uded plant width, flower stem number, flower stem length, flower number per stem, flower number per cm stem length, and days to flower. Uniconazole (1 .0 mg.L-1) applied as a medium drench to S. aemula 'New Wonder' reduced pla nt width and flower stem length without affecting flower stem number or tim e to flower. Flower number per stem and number of flowers per cm of stem le ngth were increased, resulting in attractive, compact clusters of flowers. Paclobutrazol medium drench at 4.0 mg.L-1 gave similar results, Daminozide and ethephon sprays reduced plant width; however, flower number was reduced and ethephon delayed flowering. Ancymidol did not affect the parameters me asured. When uniconazole drenches were applied to the other cultivars, plan t width and flower stem length in all cultivars except 'White Fan' decrease d as rate increased, Spray applications reduced plant width of all cultivar s except 'Mini Pink Fan'. Flower stem length was not affected in any cultiv ar, Flowering habit was improved more in S, aemula 'New Wonder','Purple Fan ', and 'Royal Fan' than in the other cultivars, Chemical names used: alpha- cyclopropyl-alpha-(4-methoxyphenyl)-5-pyrimidinemethanol (ancymidol); butan edioic acid mono (2,2-dimethylhydrazide) (daminozide); (2-chloroethyl)phosp honic acid (ethephon); beta-[(4-chlorophenyl)methyl]-alpha-(1,1-dimethyleth yl)-1H-1,2,4-triazole-1-ethanol (paclobutrazol); (E)-(s)-1-(4-chlorophenyl) -4,4-dimethy-2-(1,2,4-triazol-1-yl)-pent-1-ene-3-ol (uniconazole).