Height Control of Pixie Poinsettia with a Granular Formulation of Ancymidol1

Abstract

Abstract A granular formulation of ancymidol [α-cyclopropyl-α-(4-methoxyphenyl)-5pyrimidine] was compared to ancymidol and chlormequat [(2-chloroethyl) trimethylammonium chloride] drenches for height control of multi-branched poinsettias ( Euphorbia pulcherrima Wild.) grown in 10 cm diameter pots. Granular ancymidol at 0.125 mg ai/pot retarded plant growth with no retardation in bract diameter. Granular ancymidol at 0.25 mg ai/pot was as effective as 0.5 mg ancymidol applied as a drench and produced the ideally proportioned plants. All ancymidol treatments were more effective in height retardation than chlormequat applied at 240 mg ai/pot. Bract diameter was reduced in all ancymidol treatments and 0.5 mg ai/pot.