Nine perennial bedding plants were screened for responsiveness to the plant growth retardant, Sumagic (uniconazole-P). Two weeks after planting, plugs were treated with one foliar spray of Sumagic at 0, 40, 80, 120, or 160 ppm at the label-recommended volume. Plant growth of Gaillardia grandiflora `Goblin' was not reduced by Sumagic. Height of Achillea × `Moonshine' was reduced 8% to 12% at 4 weeks after treatment (WAT), and the reduction persisted through 8 weeks after planting (WAP) to the landscape. Phlox paniculata `Joliet' responded linearly to increasing Sumagic rate with a maximum height reduction of 32% at 160 ppm. Coreopsis grandiflora `Sunray', Rudbeckia fulgida var. Sullivantii `Goldsturm' and Monarda didyma `Blue Stocking' responded significantly to Sumagic with 30% to 60% height reductions at 4 WAT, but no persistent effects at 8 WAP. Height of Veronica alpine `Goodness Grows' was reduced 32% to 68% at 4 WAT, but all Sumagic rates resulted in persistent reductions in plant height at 12 WAP. Plant height of Alcea rosea mix and Echinacea purpurea were excessively reduced (up to 79%) at 4 WAT, but there were no persistent effects on height of Alcea in the landscape. All rates of Sumagic resulted in persistent reductions in height of Echinacea at 8 WAP, but only plants treated with 120 and 160 ppm Sumagic were still significantly shorter than controls at 12 WAP
Joyce G. Latimer and Paul A. Thomas
Thomas J. Banko and Marcia A. Stefani
Russian sage (Perovskia atriplicifolia) grown in a pine bark medium in 1-gal containers were sheared to a height of 15 cm on 20 June 1997. One day later the plants were treated with foliar sprays of Florel (ethephon) at 0, 500, or 1000 ppm. One week later, sprays of B-Nine (daminozide, 5000 ppm) or Sumagic (uniconazole, 15 ppm) were applied to some of the plants previously treated with Florel, or previously nontreated. Three weeks after initial treatments, the Florel (500 and 1000 ppm) and the Sumagic treatments, applied individually, reduced plant height by 26%. The B-Nine treatment reduced height by 18%. Combination treatments (Florel followed by Sumagic or Florel followed by B-Nine) provided additional height control Florel at 500 or 1000 ppm significantly increased branching of Perovskia. Additional treatments with B-Nine or Sumagic had little effect on this response. Florel delayed flowering by ≈7 to 10 days.
N.K. Damayanthi Ranwala, Anil P. Ranwala, and William B. Miller
One of the problems associated with preplant bulb dips into plant growth regulator (PGR) solutions is the lack of knowledge of solution efficacy as an increasing number of bulbs are treated. We evaluated the effectiveness (“longevity”) of paclobutrazol (Bonzi) and uniconazole (Sumagic) solutions repeatedly used to dip hybrid lily (Lilium sp.) bulbs. Experiments were conducted over a 2-year period, using sequential 1-minute dips into paclobutrazol (100 or 200 mg·L–1) or uniconazole (2.5 mg·L–1). No difference in plant height occurred as the number of bulbs dipped into PGR solutions increased to at least 55 bulbs per liter. This was true whether bulbs were washed (with tap water to remove soil particles attached to the bulbs) or unwashed prior to the PGR dip. These findings have an important impact on cost effectiveness of bulb dips, as the more times the solution can be used, the lower the cost. Washed bulbs were taller than unwashed bulbs due to lower PGR liquid uptake in washed bulbs (about 1 mL less per bulb) compared to the unwashed bulbs. These results indicate that the hydration condition of bulbs prior to dipping can affect the amount of PGR liquid uptake and therefore final plant height.
Brian A. Krug, Brian E. Whipker, and Ingram McCall
., 1995 ), or 3 to 4 mg/pot a.i. ( Wilfret, 1993 ). All drenches are applied when new growth emerges through the top of the substrate. Wilfret (1993) reported substrate drenches of uniconazole (Sumagic; Valent USA, Marysville, Ohio) at 1 to 2 mg/pot a
Alicain S. Carlson, John M. Dole, and Brian E. Whipker
greenhouse at night/day set points of 60/75 °F starting 9 May 2012. On 25 June 2012, when the emerging leaf whorl was ≈5-cm tall, each pot was drenched with 4 fl oz of flurprimidol (Topflor; SePRO Corp., Carmel, IN), uniconazole (Sumagic; Valent USA
Helen E. Hammond, Richard K. Schoellhorn, Sandra B. Wilson, and Jeffrey G. Norcini
daminozide, daminozide/chlormequat chloride, and paclobutrazol, two other commonly used chemical growth retardants are uniconazole (Sumagic; Valent USA Corp., Walnut Creek, CA) and Ethephon (Florel; Southern Agricultural Insecticides, Palmetto, FL). Similarly
James L. Gibson and Brian E. Whipker
Twenty-six ornamental cabbage and kale (Brassica oleracea var. acephala) cultivars were grown in 8-inch (20.8-cm) diameter pots during Fall 1998 to classify their foliage traits and determine their response to the plant growth regulator (PGR) daminozide. Cultivar vigor was classified by height. Foliage characteristics were described and cultivars of ornamental cabbage, notched ornamental kale, and curly ornamental kale were selected for retail or wholesale markets based on the shortest number of days until a significant center color change, the largest center color diameter, and attractive foliage characteristics. Two cultivars treated with 2,500 ppm (mg·L-1) daminozide and eight cultivars treated with 5,000 ppm were significantly smaller in height compared to nontreated plants. Plants were treated 6 weeks after sowing, and the response to the PGRs may have been diminished by the age of the plant. Therefore, to further investigate PGR efficacy, seven outstanding cultivars selected in 1998 were treated with 5,000 ppm daminozide or 5 ppm uniconazole 14 days after potting (4 weeks after sowing) in Fall 1999. Greater control was observed with daminozide at 5,000 ppm in 1999 with a 13% smaller plant height as compared to 9% in 1998, when compared to the nontreated control. For greater height control, PGR applications to ornamental cabbage and kale should be applied 4 weeks after sowing.
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).
James L. Gibson and Brian E. Whipker
Ornamental cabbage and kale (Brassica oleracea var. acephala) plants of cultivars Osaka White and Nagoya Red were treated with paclobutrazol and uniconazole as foliar sprays or substrate drenches. These treatments were compared to the industry standard of daminozide foliar sprays. Applying drenches of paclobutrazol (a.i.) at 4 mg/pot or uniconazole (a.i.) at 1 mg/pot (28,350 mg = 1.0 oz) resulted in 6% or 17%, respectively, shorter `Osaka White' plants while a 2 mg/pot paclobutrazol drench or a uniconazole drench at 0.25 mg/pot resulted in 25% shorter `Nagoya Red' plants. Although effective, the expense of substrate drenches for both plant growth regulators (PGRs) would not be economically feasible for growers to use. Paclobutrazol foliar sprays at concentrations of up to 80 mg·L-1 (ppm) were ineffective in controlling plant height and diameter of either `Osaka White' or `Nagoya Red'. A uniconazole foliar spray of 16 mg·L-1 resulted in 17% shorter `Nagoya Red' plants and 6% shorter `Osaka White' plants. A daminozide foliar spray of 2500 mg·L-1, sprayed twice, resulted in 21% shorter plants for both cultivars. Spraying daminozide would provide optimal height control for the retail grower. Although spraying daminozide twice controlled plant height and costs half the amount of an uniconazole spray at 16 mg·L-1, plant diameter was not affected with daminozide, therefore a wholesale grower who would desire a smaller diameter plant should use a uniconazole spray of 16 mg·L-1.
Terri Woods Starman
This study investigated the effects of concentration and application time of uniconazole as a spray for single- or double-pinched ornamental pepper (Capsicum annuum L. `Holiday Cheer'). Concentrations from 5.0 to 15.0 mg·liter-1 gave adequate height control, except that 15.0 mg·liter-1 reduced height excessively when applied 8, but not 10, weeks after sowing. Increasing uniconazole concentration increased red fruit percentage when applied at 10, but not 8, weeks after sowing. These results indicate that the later application was beneficial and may lessen the overdosing problem associated with triazole growth regulators. Chemical name used: (E)-(S)-1-(4-chlrophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)-pent-1-ene-3-oll(uniconazole).