Evaluation of Application Methods of Ancymidol and Daminozide for Height Control of Chrysanthemum

Abstract Plant size, and number of flowers of chrysanthemums ( Chrysanthemum × morifolium Ramat. cvs. Yellow Mandalay and Royal Trophy) were reduced when grown in a soil containing granular α-cyclopropyl-α-(4-methoxyphenyl)-5 pyrimidine (ancymidol) or provided ancymidol drench or butanedioic acid mono-(2,2-dimethylhydrazide) (daminozide) spray but not when sprayed with ancymidol (0.5 mg). Granular ancymidol at 0.5 mg/pot reduced plant height 9% on ‘Yellow Mandalay’ and 30% on ‘Royal Trophy’ compared to controls. Foliar applications of daminozide reduced height 27% on ‘Yellow Mandalay’ and 47% on ‘Royal Trophy’.