Effect of Timing and Number of Applications of Chlormequat and Ancymidol on the Growth and Flowering of Seed Geraniums1

Abstract ‘Sprinter Scarlet’ and ‘Sprinter Salmon’ geranium ( Pelargonium × hortorum L. H. Bailey) treated with repeated applications of (2-chloroethyl) trimethyl ammonium chloride (chlormequat, CCC) at 1500 ppm and of α-cyclopropyl-α-(4-methoxyphenyl)-5-pyrimidine-methanol (ancymidol, A-Rest) at 200 ppm flowered significantly earlier than control plants, but differences among growth retardant treatments were non-significant. Growth control increased both with delay in treatment and with increasing number of applications. Flower initiation, as determined by microscopic examination of apical meristems, occurred 1 to 2 weeks earlier in growth-retardant treated plants.