Foliar application of 0.4 to 0.6% of an aqueous solution of sodium 2,3:4,6-di-O-isopropylidene-2-keto-L-gulonate) (dikegulac, Atrinal) was effective as a pinching agent under commercial growing conditions on all azalea (Rhododenron simsii Planch.) cultivars tested. One to 2 weeks after application the upper leaves turned yellow. Within 4 weeks after treatment the axillary shoots began to elongate and 4-8 weeks later the foliage regained a dark green color. Reproductive shoots treated with dikegulac produced new axillary shoots, but treatment should precede flower initiation for optimal results. At all dosage rates a better pinching effect was obtained with higher spray volumes. A spray volume of 200-300 ml/m2 (2-3 qts/100 ft2), depending on growth stage, is suggested. Dikegulac is a very promising chemical pinching agent for greenhouse azaleas.