data; a bbott Laboratories (gibberellin), Miller Chemical Co. (Vapor Gard), and Uniroyal (daminozide) for chemical supplies: and to the Virginia State Horticultural Society and a bbott Laboratories for partial financial assistance. The cost of
R.E. Byers, D.H. Carbaugh, and C.N. Presley
Kenneth C. Sanderson, Durward A. Smith, and John A. McGuire
Alabama Agricultural Experiment Station journal series no. 11-933560, Appreciation is expressed to Yoder Brothers, Barberton, Ohio, for the chrysanthemum cuttings and Uniroyal, Bethany, Conn., for the daminozide used in this study. The cost
Arvazena E. Clardy, Sabrina L. Shaw, and William F. Hayslett
Red Delano chrysanthemum cuttings were transplanted into 15 cm pots. Fertilizer treatments were started immediately. Initial fertilizer rates were 14.8 cc of the designated formulation per pot. Two formulations of fertilizer, 20-20-20 and 5-50-17 NPK, were used in excessive rates to determine if it would override the effects of the growth inhibitors. Paclobutrazol, uniconizole, and daminozide were used to retard growth. Three rates-30, 60, and 120 ppm of paclobutrazol, and 10, 20, and 40 ppm of uniconizole and one rate of 25 % daminozide were foliar applied (two applications) on the plants. After two weeks the plants were treated with the growth retardants and an additional treatment of fertilizer were added at the rate of 29.6 cc per pot. Measurements taken were plant height, top fresh weight, root fresh weight, and root development. ANOVA was used to determine differences and interactions. Significant differences were noted in plant height and root development.
Amir Rezazadeh and Richard L. Harkess
produce compact plants ( Gibson and Whipker, 2001 ; Krug et al., 2005 ; Schluttenhofer et al., 2011 ; Warner and Erwin, 2003 ). Chlormequat and daminozide are growth regulators frequently applied to limit plant height in poinsettia [ Euphorbia
Amir Rezazadeh, Richard L. Harkess, and Guihong Bi
Harkess, 2015 ). Flurprimidol is effective as a foliar spray or substrate drench for height control ( Currey and Lopez, 2011 ; Krug et al., 2005 ). Daminozide is not a triazole but rather suppresses plant height by reducing the conversion of GA to active
Christopher J. Currey, Nicholas J. Flax, and Kellie J. Walters
, or 3000 mg·L −1 (Cycocel; OHP, Mainland, PA)], daminozide [1250, 2500, or 5000 mg·L −1 (Dazide, Fine Americas)], ethephon [250, 500, or 1000 mg·L −1 (Collate, Fine Americas)], flurprimidol [10, 20, or 40 mg·L −1 (Topflor; SePro, Carmel, IN
Christopher J. Currey and Roberto G. Lopez
’ poinsettia treated with flurprimidol drenches (Expt. I) and for ‘Classic Red’ and ‘Freedom Salmon’ poinsettia treated with flurprimidol drenches or a daminozide and chlormequat chloride foliar spray (Expt. II). Plant height was measured weekly and plotted in
Kelly P. Lewis, James E. Faust, James D. Sparkman IV, and Larry W. Grimes
Poinsettia (Euphorbia pulcherrima Willd. Ex Klotzch) `Freedom Red' (FR), `Success Red' (SR), and `Winter Rose Dark Red' (WRDR) and pansy (Viola wittrockiana Gams.) `Colossus Yellow Blotch' (CYB), `Delta Pure Yellow' (DPY), and `Majestic Giants Purple' (MGP) were treated with 14 different tank mix combinations of daminozide and chlormequat ranging from 0 to 4500 mg·L-1 daminozide and 0 to 1500 mg·L-1 chlormequat. The tank mix treatments reduced stem elongation for all three poinsettia cultivars. Total bract area of FR and canopy bract diameter of WRDR decreased linearly as daminozide or chlormequat concentration increased, while bract area of SR was affected by daminozide alone. Anthesis was not delayed by any of the plant growth regulator (PGR) applications. For pansies, growth responses to the PGR treatments varied with cultivar. CYB growth was affected by daminozide alone, DPY growth was affected by daminozide and/or chlormequat, while MGP growth was relatively insensitive to both PGRs. Time to flower of pansy was not affected by the PGR applications. Chemical names used: 2-chloroethyl N,N,N-trimethylammonium chloride (chlormequat chloride); butanedioic acid mono (2,2-dimethylhydrazide) (daminozide).
Harry K. Tayama and Stephen A. Carver
Residual activity of a single uniconazole spray (15 mg a.i./liter), uniconazole drench (600 μg a.i./pot), and daminozide spray (5000 mg a.i./liter) were compared to an untreated control using the `Bright Golden Anne' chrysanthemum [Dendranthema grandiflorum (Ramat.) Kitamura]. Based on weekly internode growth, spray and drench treatments with daminozide and uniconazole remained active for 2 to 2.5 and 3 to 3.5 weeks, respectively. Chemical names used: butanedioic acid mono (2,2-dimethylhydrazide) (daminozide); (E)-1-(p-chlorophenyl)-4,4-diemethyl 1-2(1,2,4-triazol-2-yl)-l-penten-3-01 (uniconazole).
Brian E. Whipker and Ingram McCall
Plant growth retardant (PGR) foliar sprays of daminozide at 4,000 or 8,000 mg·L-1 (ppm) and paclobutrazol drenches of 2 or 4 mg a.i. per pot were applied to `Big Smile', `Pacino', `Sundance Kid', `Sunspot', and `Teddy Bear' pot sunflowers (Helianthus annuus L.) to compare their chemical height control. Plant height varied among the cultivars due to genetic variation. The percentage reduction in plant height from the untreated control only was significant at the PGR level, indicating similar responses of all five cultivars to each PGR rate. Paclobutrazol drenches at 2 mg and daminozide foliar sprays at 4,000 or 8,000 mg·L-1 reduced plant height by about 24% when compared to the control. Paclobutrazol drenches at 4 mg produced plants that were 33% shorter than the control. Plant diameter of `Big Smile', `Pacino', or `Sundance Kid' was unaffected by daminozide, whereas `Sunspot' plants were smaller than the controls. Paclobutrazol drenches at 2 or 4 mg decreased plant diameter for all cultivars except `Teddy Bear', with the reduction being greater as paclobutrazol drench rates increased. The number of inflorescence buds increased by ≥18% with the use of daminozide sprays, while paclobutrazol drenches at 2 or 4 mg had no effect when compared to the untreated control. Paclobutrazol drenches of 2 or 4 mg offer the economic advantage to growers of increased plant density on greenhouse benches, while plants treated with daminozide had an increased bud count but would require a greater amount of bench space.