scholarly journals Ornamental Cabbage and Kale Growth Responses to Daminozide, Paclobutrazol, and Uniconazole

2001 ◽  
Vol 11 (2) ◽  
pp. 226-230 ◽  
Author(s):  
James L. Gibson ◽  
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.

2003 ◽  
Vol 13 (1) ◽  
pp. 132-135 ◽  
Author(s):  
James L. Gibson ◽  
Brian E. Whipker

Vigorous osteospermum (Osteospermum ecklonis) cultivars Congo and Wildside received foliar sprays of daminozide or daminozide + chlormequat (Expt. 1). Both cultivars responded similarly to the plant growth regulator (PGR) treatments. Only a limited amount of plant height control occurred using 5,000 mg·L-1 (ppm) daminozide + 1,500 mg·L-1 chlormequat or 5,000 mg·L-1 daminozide + 3,000 mg·L-1 chlormequat. Flowering was delayed, phytotoxicity was observed, while peduncle length increased, suggesting that higher concentrations of daminozide or chlormequat may or not be effective at any concentration and may result in increased phytotoxicity. In Expt. 2, `Lusaka' received foliar sprays or substrate drenches of paclobutrazol or uniconazole. Foliar sprays ≤80 mg·L-1 paclobutrazol or ≤24 mg·L-1 uniconazole were ineffective in controlling plant growth. Substrate drenches of paclobutrazol (a.i.) at 8 to 16 mg/pot (28,350 mg = 1.0 oz) produced compact plants, but at a cost of $0.23 and $0.46/pot, respectively, would not be economically feasible for wholesale producers to use. Uniconazole drenches were effective in producing compact `Lusaka' osteospermum plants. Uniconazole drench concentrations of 0.125 to 0.25 mg/pot were recommended for retail growers, while wholesale growers that desire more compact plants should apply a 0.25 to 0.5 mg/pot drench. Applying uniconazole would cost $0.06 for a 0.25 mg drench or $0.12 for a 0.5 mg drench.


2006 ◽  
Vol 24 (3) ◽  
pp. 165-168
Author(s):  
Stanislav V. Magnitskiy ◽  
Claudio C. Pasian ◽  
Mark A. Bennett ◽  
James D. Metzger

Abstract Soaking French marigold seeds in growth regulator solutions produced larger reductions in seedling height than foliar sprays. Seeds soaked in 1 to 5 ppm uniconazole solutions for 0.15, 5, or 45 min resulted in plants that were up to 23% shorter than controls at 30 DAS, whereas foliar applications of 10 to 20 ppm uniconazole solutions resulted in plants 18% shorter than controls at 14 DAS. French marigold seedlings from seeds soaked in 60 pm ancymidol for 5 or 45 min were 5 or 6%, respectively, shorter than controls. Foliar spray applications of 25 or 100 ppm ancymidol to French marigold seedlings resulted in plants 8% shorter than controls. Chlormequat solutions applied either as a seed soak (1000–5000 ppm) or foliar spray (500–3000 ppm) did not reduce French marigold seedling height. Emergence of French marigold seedlings from seeds soaked in uniconazole, ancymidol, or chlormequat solutions was not different from that of control seeds. No effect on seedling height or emergence was found when soaking celosia seeds in uniconazole, ancymidol, or chlormequat solutions. Spraying celosia seedlings with uniconazole, ancymidol, or chlormequat solutions did not reduce seedling height.


2015 ◽  
Vol 25 (1) ◽  
pp. 71-75 ◽  
Author(s):  
Amir Rezazadeh ◽  
Richard L. Harkess

Purple firespike (Odontonema callistachyum), native to Central America, has potential for use as a new flowering potted plant. The effects of number of pinches (zero, one, or two) and number of cuttings (one, two, or three) per 6-inch pot were evaluated on the control of plant height. Plant height was suppressed as the pinch number increased. The greatest reduction was recorded with one cutting per pot and two pinches. The maximum number of branches per pot was recorded with two pinches and three cuttings per pot. In a second experiment, plant growth regulators (PGR) were also tested for efficacy of height control; 2 weeks after pinching, foliar sprays of paclobutrazol, flurprimidol, daminozide, chlormequat, and a tank-mix of daminozide + chlormequat or media drenches of paclobutrazol, uniconazole, or flurprimidol were applied. Plant height, leaf area, and leaf dry weight were recorded at 3, 6, and 9 weeks after PGR application. Maximum height control was obtained with uniconazole drench at 8 ppm, resulting in plants 22 cm tall, 61% shorter than the untreated control (56 cm); however, it resulted in severe leaf distortion. Plant height was 56% and 46% shorter than the control using drenches of paclobutrazol at 30 ppm and flurprimidol at 15 ppm, respectively. Daminozide spray at 2000 ppm and tank-mix of daminozide + chlormequat at 4500/1500 ppm suppressed stem elongation by 20.3% and 19%, respectively. Plants treated with paclobutrazol drench at 30 ppm reduced leaf area and leaf dry weight compared with other PGRs. Chlormequat spray at tested concentrations was ineffective for controlling firespike plant growth. The most attractive potted plants were produced using a drench application of paclobutrazol at 10 or 15 ppm.


HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 438D-438
Author(s):  
Brian E. Whipker ◽  
Shravan Dasoju

Plant growth retardant (PGR) foliar spray treatments (mg•liter–1) of daminozide at 1000 to 16,000; paclobutrazol from 5 to 80; and uniconazole from 2 to 32 were applied to `Pacino' pot sunflowers (Helianthus annuus) to compare their effectiveness at chemical height control. When the first inflorescence opened, the number of days from seeding until flowering, total plant height measured from the pot rim to the top of the inflorescence, inflorescence diameter, and plant diameter were recorded. Total plant height, plant diameter, inflorescence diameter, and days until flowering were significant for the PGR treatment interaction. Marketable-sized plants grown in the 1.2-liter pots were produced with uniconazole concentrations between 16 and 32 mg•liter–1 or with daminozide concentrations between 4000 and 8000 mg•liter–1. Paclobutrazol foliar sprays up to 80 mg•liter–1 had little effect and higher concentrations or medium drench treatments should be considered.


2018 ◽  
Vol 28 (4) ◽  
pp. 445-449
Author(s):  
Shawn D. Lyons ◽  
William B. Miller ◽  
H. Christian Wien ◽  
Neil S. Mattson

When grown in containers, pineapple lily (Eucomis sp.) can produce excessively long foliage and tall scapes, particularly in cultivars with tall pineapple lily (Eucomis comosa) parentage. Height control, through the use of plant growth regulators (PGRs), is necessary to improve crop quality of potted pineapple lily. In year 1 of these trials, bulbs of cultivars Reuben, Tugela Jade, and Tugela Gem were given substrate drenches of flurprimidol or paclobutrazol, each at 2, 4, or 6 mg per 6-inch pot. Drenches were applied at the “visible inflorescence” stage. As concentration increased, scapes were generally shorter in all cultivars for both PGRs, but there was no effect on foliage length or production time. At the rates tested, the reduction in scape length was insufficient to produce marketable plants of the three cultivars. In the second year, substrate drenches were applied at an earlier stage than in year 1, at “leaf whorl emergence,” when shoots were about 7 cm tall. The PGR treatments were notably more effective at controlling plant height in the second year. As concentration increased, scape and foliage length was reduced relative to the controls in all three cultivars for both PGRs. For all cultivars, inflorescence leaning and toppling were sharply reduced at all application rates compared with untreated controls. The reduction in plant height observed in year 2, particularly in plants treated with 4 or 6 mg/pot, resulted in plants with compact scapes and foliage proportional with their 6-inch containers.


2005 ◽  
Vol 15 (2) ◽  
pp. 330-332 ◽  
Author(s):  
Kimberly R. Hilgers ◽  
Cynthia Haynes ◽  
William R. Graves

The objective of this study was to determine the efficacy of plant growth regulators applied as foliar sprays on height and branching of seashore mallow (Kosteletzkya virginica). Five chemical plant growth regulators were applied: ancymidol [15, 25, and 50 mg·L–1 (ppm)] (A-Rest; Elanco Products Co., Indianapolis), dikegulac sodium (500, 1000, and 1500 mg.L–1) (Atrimmec; PBI/Gordon Corp., Kansas City, Mo.), paclobutrazol (10, 20, and 60 mg·L–1) (Bonzi; Uniroyal Chemical Co., Middlebury, Conn.), chlormequat chloride (CCC) (750, 1000, and 1500 mg·L–1) (Cycocel; Olympic Horticultural Products, Mainland, Pa.), and CCC/daminozide mixes (1000/2500, 1000/5000, and 1500/5000 mg·L–1) (Cycocel and B-Nine; Uniroyal Chemical Co.). Ten replicate plants of each concentration were evaluated weekly for plant height and number of branches for 8 weeks. Plants that received CCC and CCC/daminozide treatments at all concentrations and paclobutrazol at 60 mg·L–1 were 60%, 60%, and 48% shorter than control plants and had 113%, 100%, and 75% more branches than control plants, respectively. All concentrations of ancymidol and dikegulac sodium-treated plants were similar to control plants. Paclobutrazol was applied twice, and only the highest concentration was effective for height control. Chlormequat chloride at the lowest concentration was as effective as all other concentrations of CCC and CCC/daminozide.


1998 ◽  
Vol 8 (1) ◽  
pp. 86-88 ◽  
Author(s):  
Brian E. Whipker ◽  
Shravan Dasoju

Plant growth retardant (PGR) foliar sprays (in mg·L−1) of daminozide at concentrations from 1,000 to 16,000; paclobutrazol from 5 to 80; and uniconazole from 2 to 32 were applied to `Pacino' potted sunflowers (Helianthus annuus L.) to compare their effectiveness at chemical height control. Plants were grown in 650-mL or 1.2-L pots. When the first inflorescence started to shed pollen, number of days from seeding until anthesis, total plant height measured from the pot rim to the top of the inflorescence, inflorescence diameter, and plant diameter were recorded. There was no significant difference in plant height between `Pacino' plants grown in 650-mL or 1.2-L pots. Total plant height, plant diameter, inflorescence diameter, and days until flowering were significant for the PGR treatment main effect. Marketable-sized plants grown in the 1.2-L pots were produced with uniconazole concentrations from 16 to 32 mg·L−1 or with daminozide concentrations from 4,000 to 8,000 mg·L−1. Paclobutrazol foliar sprays up to 80 mg·L−1 had little effect, and higher foliar spray concentrations or substrate drench treatments may be needed to effectively control height.


2016 ◽  
Vol 26 (1) ◽  
pp. 6-11 ◽  
Author(s):  
Amir Rezazadeh ◽  
Richard L. Harkess ◽  
Guihong Bi

The effect of plant growth regulators (PGRs) on growth and flowering of potted red firespike (Odontonema strictum) were examined in two experiments. In Expt. 1, foliar spray applications of daminozide, uniconazole, paclobutrazol, or flurprimidol or media drenches of paclobutrazol or flurprimidol were applied. In Expt. 2, foliar spray application of daminozide or media drenches of paclobutrazol or flurprimidol were further tested for efficacy of height control. Both studies included an untreated control. In Expt. 1, drench applications of paclobutrazol and flurprimidol resulted in plants 65% or 46% to 62% shorter than control, respectively. Paclobutrazol and flurprimidol drenches also decreased overall plant growth by 81% to 88% and 74% to 84%, respectively, compared with the control plants. PGRs did not affect number of inflorescences; however, paclobutrazol and flurprimidol delayed flowering 23 to 31 days. In Expt. 2, plants treated with flurprimidol or paclobutrazol drenches were shorter than the control. The greatest reduction in total plant growth occurred using a flurprimidol drench at 0.47 mg/pot, which resulted in plants 78% smaller than the untreated control. Paclobutrazol and flurprimidol increased the time to flowering 11 to 27 days and 10 to 26 days, respectively. The most attractive and well-shaped plants were achieved with flurprimidol applied at 0.24 mg/pot or applications of paclobutrazol at 0.35 mg/pot.


HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 434B-434 ◽  
Author(s):  
James L. Gibson ◽  
Brian E. Whipker

Ornamental cabbage and kale (Brassica oleracea var. acephala L.) plants of cultivars `Osaka White' and `Nagoya Red' were treated with paclobutrazol and uniconazole as foliar sprays or soil drenches. These treatments were compared to the industry standard of daminozide foliar sprays. Ten plant growth regulator (PGR) drench treatments (in mg a.i./pot) were applied 22 days after potting: paclobutrazol at 1 to 16 and uniconazole at 0.125 to 2. Thirteen PGR foliar sprays (in mg/L) were also applied: paclobutrazol at 5 to 80, uniconazole at 2 to 32, daminozide at 2500, 2500 (twice, with the second application occurring 14 days later), or 5000, and an untreated control. Applying drenches of paclobutrazol at 4 mg or uniconazole at 0.5 mg controlled height by 16 to 25%, but at the cost of $0.11 per pot would not be economically feasible for growers to use. Paclobutrazol foliar sprays at concentrations of up to 80 mg/L were ineffective in controlling plant height and diameter of either `Osaka White' or `Nagoya Red'. Uniconazole foliar sprays between 2 and 8 mg/L were effective in controlling height (by 19%) and diameter (by 15%) as daminozide foliar sprays of 2500 mg/L, sprayed twice, with a cost to the grower of $0.02 per pot.


Sign in / Sign up

Export Citation Format

Share Document