Growth Retardant Application to Canna × generalis ‘Florence Vaughan’

Abstract The effects of 15 to 45 ppm Cutless (flurprimidol), 2500/1500 to 7500/1500 ppm B-Nine/Cycocel tank mixes (daminozide/chlormequatchloride), and 20 to 60 ppm Sumagic (uniconazole) on the vegetative growth and flowering of Canna x generalis ‘Florence Vaughan’ were determined during container nursery production and landscape establishment. Vegetative heights 30 and 60 days after treatment (DAT) and vegetative and inflorescence heights at first and second flower were suppressed by all plant growth retardants (PGRs). There was no delay in flowering of the first inflorescence from any PGR treatment, and a three to seven day delay in flowering of the second inflorescence with only Sumagic. Vegetative height was suppressed quadratically 14–28% (30 DAT) and linearly 19–40% (60 DAT) by increasing Cutless rates. Inflorescence heights of plants treated with 15 or 30 ppm Cutless were suppressed proportionally to foliage heights without any detrimental effect on floral display. Heights of plants treated with Cu...