Effects Of Flurprimidol Research Articles

Gibberellin Inhibitor Treatments Before Planting Control Plant Height of Narcissus tazetta by Affecting Growth Parameters

The effects of flurprimidol and paclobutrazol, treatments as preplant bulb soaks on plant height, growth parameters and other properties of Narcissus tazetta L. grown in pots were investigated. Bulbs were soaked in flurprimidol at 0, 10, 20 mg L-1 or paclobutrazol at 0, 100, 200 mg L-1 before planting. The effects of gibberellin inhibitors on the flower number, flowering time, flower life, plant height, leaf length and quantitative measurements (specific leaf area, leaf area ratio, leaf thickness, leaf weight ratio and stem weight ratio) were determined. When narcissus reached to the sale stage, plants were taken to the laboratory where the temperature stable at 20°C to evaluate the postproduction quality. The shortest plant height (6.25 cm, 63% shorter than control) was obtained from the 20 mg L-1 flurprimidol application. Plants applied with 200 mg L-1 paclobutrazol were 59% shorter than control with 7.00 cm plant height. Gibberellin inhibitors also shortened the leaf length and increased the leaf thickness, whereas decreased leaf area ratio and specific leaf area by shortening the plant height. The effects of gibberellin inhibitors on plant height continued after harvest (production) in marketing and consumer (laboratory) conditions. The plant heights of treated plants were 10.87 (20 mg L-1 flurpirmidol) and 10.37 (200 mg L-1 paclobutrazol) cm, while with the control plants were 26.75 cm in with laboratory conditions.

Effects of plant growth regulators on the plant height and quantitative properties of Narcissus tazetta

The effects of flurprimidol, paclobutrazol, and ethephon treatment as soil drench on plant height and quantitative and other properties of native narcissus (Narcissus tazetta L.) plants grown in pots were investigated. When the plants were 7?10 cm tall, flurprimidol and paclobutrazol at 0, 1, and 2 mg/pot and ethephon at 0, 37.5, and 75 mg/pot were applied as soil drenches. The effects of plant growth retardant treatments on plant height, leaf length, time of flowering, number of flowers, and flower life were determined. In addition, quantitative measurements (leaf area ratio, specific leaf area, leaf thickness, leaf weight ratio, and stem weight ratio) were analyzed in native narcissus. When narcissus grown in pots in the greenhouse reached the sale stage, the plants were taken to the laboratory at 20 °C to evaluate the postproduction life and quality of pot plants. Flurprimidol, paclobutrazol, and ethephon shortened plant height. The shortest plant height was obtained from 2 mg/pot paclobutrazol; plant height was 5.42 cm, 65% shorter than the untreated controls. Chemical applications also shortened leaf length. The shortest leaf length (13.25 cm) was obtained from the 2 mg/pot paclobutrazol treatment. The chemical treatment decreased the leaf area ratio and specific leaf area, but increased the leaf thickness and leaf weight ratio compared to the control plants. The effects of treatments on plant height continued in laboratory (home-office) conditions after production. The shortest plant height (9.5 cm) was obtained from the 2 mg/pot paclobutrazol treatment, whereas the height of untreated control plants was 24.25 cm during the postproduction life of pot plants.

Paclobutrazol and Flurprimidol Control Stem Elongation of Potted Star of Bethlehem

Plant growth regulators (PGRs) are effective tools for controlling potted plant growth. In this article, the effects of flurprimidol, paclobutrazol, and ethephon media drenches on stem elongation of star of bethlehem (Ornithogalum thyrsoides and Ornithogalum dubium) were investigated. At the lowest paclobutrazol (0.5 mg/pot) and flurprimidol rates (0.05 mg/pot) tested, plant height was reduced 20% to 35% compared with controls in all tested cultivars. Ethephon applied as a media drench when plants reached visible bud (VB) stage had no effect on plant height or flowering. A consumer preference survey of ‘Fire Star’ star of bethlehem (O. dubium) plant height showed that about 60% of participants preferred PGR-regulated plants. With every level of preference increase for shorter plants (on a scale of 1 to 5), participants were willing to pay $0.48 more for the shorter plant.

In vitro conservation of pointed gourd (Trichosanthes dioica) germplasm through slow-growth shoot cultures: Effect of flurprimidol and triiodobenzoic acid

The effects of growth retardants, flurprimidol and triiodobenzoic acid (TIBA) were investigated on the development of slow-growth cultures aimed for in vitro conservation of pointed gourd (Trichosanthes dioica) germplasm. Shoot cultures maintained on MS medium supplemented with flurprimidol (1.0, 2.0, 5.0, 7.5, 8.8, 10.0, 12.5, 15.0, 20.0μM) or TIBA (10−3, 10−4, 10−5, 10−6, 10−7, 10−8M) were stored at 25°C and 9°C. In general, flurprimidol in the medium suppressed shoot growth, but it promoted leaf (up to 5.0μM) and root development (all the tested concentrations). The optimum concentration of flurprimidol for storage of the cultures was 7.5μM as it supported culture survival for 784days, when stored at 9°C. In general, TIBA promoted shoot growth and number of leaves per culture at low concentrations (10−8M), but it had suppressive effect at the higher concentrations. However, root number per culture decreased significantly in response to even 10−8M TIBA. The shoot cultures maintained on medium containing 10−8M TIBA survived for 280d, while the cultures grown on GR-free MS medium and stored at 9°C survived much longer (∼700d). Use of TIBA for slow-growth of pointed gourd shoot cultures did not offered any advantage over the GR-free MS medium. The cultures stored at 9°C survived much longer than those stored at 25°C. The GR-free MS medium may be preferable to the 7.5μM fluprimidol as it supported culture survival for up to 700d at 9°C, and avoids the additional cost and the possible undesirable physiological and genetic effects of the growth retardant. But when low temperature storage is not feasible, the cultures may be maintained on MS medium supplemented with flurprimidol (5.0 or 7.5μM) as the cultures survived up to 364d at 25°C.

The effect of flurprimidol on Allium rosenbachianum Reg. forced in pots

The effect of flurprimidol on Allium rosenbachianum (Reg.) flowering and forcing period was studied. Bulbs of 18-20 cm circumference were used in the experiment. Two methods of retardant application were used: bulbs soaking before planting and triple spraying of plants during the vegetation period (in the stage of leaf rosette, open leaves and in the phase of green, ‘sitting’ bud). Flurprimidol was used in the following doses: 15 mg ∙ dm-3, 30 mg ∙ dm-3, 45 mg ∙ dm-3 and control (plants treated with distilled water). Bulbs were planted into pots on the 20th of October and ‘wet cooled’ for 14 weeks in the temperature of 9°C. During forcing in a greenhouse, morphological features of plants were observed. It was noted that flurprimidol may be effectively used for suppressing A. rosenbachianum forced in a greenhouse as a pot plant. Flurprimidol used in concentration of 45 mg ∙ dm-3 significantly inhibited growth of shoots and length of flower pedicels and leaves and increased number of flowers in inflorescences at the same time. Soaking bulbs of A. rosenbachianum in flurprimidol solution before planting shortened forcing period by 4 days.

Response of Fuchsia hybrida cuttings to flurprimidol and naphthaleneacetic acid application

Auxins are the only compounds used in commercial plant propagation to stimulate rooting, although efforts have been made to find other efficient compounds. Another group of rooting promoters could be plant growth retardants (PGRs) which act as inhibitors of gibberellin synthesis. The aim of the experiment was to determine the effect of flurprimidol and naphthalene-1-acetic acid (NAA) applied by quick-dip method on rooting and development of <em>Fuchsia hybrida</em> 'Swingtime' cuttings and their subsequent growth. Anatomical analysis of the rooting process was also done. Flurprimidol and NAA did not influence the percentage of rooted fuchsia cuttings but increased the number of adventitious roots. Both compounds were involved in earlier formation of root primordia. Flurprimidol and NAA, used simultaneously or separately, increased the number and length of axillary shoots of fuchsia cuttings. The effect of flurprimidol on the number of roots and shoots was stronger than that of NAA, but diminished after transplanting the rooted cuttings. The influence of flurprimidol on axillary shoot length was weaker as its concentration increased.

The influence of flurprimidol on the morfological traits, flowering and decorative value of Pelargonium hortorum 'Omega'

The effects of flurprimidol at the concentration of 7.5 i 15 mg×dm<sup>-3</sup> on the growth and flowering of <i>Pelargonium hortorum</i> 'Omega' were examined in the years 2003 and 2004. Pelargonium plants were sprayed either once or twice; 2 weeks after planting rooted seedlings - first, and next - 2 weeks later. At the beginning, the plants were grown in a greenhouse, and then in a foil tunnel. Flurprimidol at the concentration of 15 mg×dm<sup>-3</sup> increased the number of leaves and intensified their colour, but reduced the plant height and diameter, shortened peduncles lowering their decorative value. 7.5 mg×dm<sup>-3</sup> of the retardant had weaker effects on <i>Pelargonium</i> morphological traits, but resulted in more abundant flowering, compact and proportional conformation and high decorative value.

Gibberellins and antheridiogen on sex in Blechnum spicant L.

The role of gibberellins (GAs) in determining sex in the gametophyte of the fern Blechnum spicant L. was studied through (a) the effect of exogenous GA(4+7) and GA3 (b) quantitation of the endogenous levels of GA1, GA3, GA4, GA7, GA9, and GA20 in male and female gametophytes, and (c) the effect of flurprimidol, a GAs biosynthesis inhibitor of the steps of oxidation of ent-kaureno to ent-kaurenoic acid. Our results show that GA(4+7) had a slight effect of inducing either male or female sexual organs, antheridia and archegonia, respectively. The endogenous GAs content was not significantly different between sexes, but the GA4, GA7, and GA20 levels were raised above those of the other GAs in both sexes. Neither antheridiogen biosynthesis nor antheridia formation was inhibited by flurprimidol. Gametophytes regenerated from homogenized mature gametophytes (HG) show a different physiological behavior than spore-derived gametophytes. In the first case, gametophytes are males and synthesize antheridiogen before they attain maturity, in contrast to what occurs in spore-derived gametophytes which are females and synthesize antheridiogen when mature.

Gas exchange and water relations of Fraxinus americana affected by flurprimidol.

Effects of flurprimidol on plant water relations and leaf gas exchange were investigated in one-year-old white ash (Fraxinus americana L.) seedlings subjected to soil water deficits. Flurprimidol (20 mg kg(-1) of soil equivalent) was applied to the soil surface of pot-grown seedlings after shoot growth was completed. Two months after flurprimidol application, water was withheld from one-half of the seedlings. Leaf water relations and gas exchange parameters were measured 5, 7, 10, 14, 18 and 22 days after withholding water. Under both irrigated and nonirrigated conditions, flurprimidol treatment resulted in reduced net CO(2) assimilation rate and transpirational water loss of seedlings as a result of decreased stomatal conductance. Consequently, flurprimidol-treated seedlings had higher leaf water potential and relative water content than untreated seedlings. Nonirrigated flurprimidol-treated seedlings also had greater turgor and sap osmolality and lower osmotic potential at full turgor than seedlings in the other treatments, indicating that flurprimidol increased osmotic adjustment. Under water-stress conditions, water use efficiency was lower and gas exchange efficiency was higher in flurprimidol-treated seedlings than in untreated seedlings, suggesting that flurprimidol treatment enhances survival of plants subjected to soil water deficits.

The effect of flurprimidol on bud flush, shoot growth, and on endogenous gibberellins and abscisic acid of Douglas-fir seedlings

For 4-month-old Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] seedlings under 17-h photoperiods in controlled environment conditions, flurprimidol (α-(1-methlyethyl-α-[4-(trifluoromethoxy)phenyl]-5-pyrimidine-methanol) decreased incidence of second flushing from 81 to 54% and significantly reduced height growth in the second year following low-temperature treatment, in comparison to untreated controls. For seedlings under 15-h photoperiods, flurprimidol had only limited early effects, but after a period of bud dormancy, shoot growth was reduced to one-third that of the untreated controls. Under both photoperiods flurprimidol significantly depressed abscisic acid levels and gibberellin-like bioactivity. These results suggest that growth reduction in this conifer by flurprimidol may well involve inhibition of gibberellin biosynthesis.

Effects of Rate and Repeat Application of Flurprimidol on the Growth of Photinia × fraseri and Ilex crenata ‘Compacta’

Flurprimidol, α-(1-Methylethyl)-α-[4-(trifluoromethoxy)phenyl]-5-pyrimidine-methanol, was applied to three month plants of Photinia × fraseri in 5.6 L (6 qt) containers and Ilex crenata ‘Compacta’ in 2.8 L (3 qt) containers as foliar sprays at 0, 33, 66, 132, 264, 528, 1056, 2112, 4224, and 8448 ppnl. Growth-medium drench applications with flurprimidol were applied at 0, 2, 4, 8, 16, 32, 64, 128, 256, and 512 ppm solution, 0.5 L (17 oz) per 5.6 L (6 qt) container to Photinia. The initial foliar spray treatments and the growth medium drench treatments were applied on July 14, 1983. All test plants were planted in soil on December 9, 1983. Foliar spray treatments were repeated on July 19, 1985. Flurprimidol at low concentrations as a spray and drench substantially reduced plant size with little or no phytotoxicity. Duration of growth suppression increased as rate increased. Flurprimidol at low rates reduced growth for the remainder of the growing season in which it was applied. At higher rates growth was also reduced in the following growing season. Minor leaf distortion of smaller leaves was obtained at low rates and leaf distortion appeared to increase slightly at higher rates. Shoot growth after the effects of flurprimidol were no longer apparent appeared normal. Results indicate that flurprimidol alone and in conjunction with pruning can be helpful in maintaining woody landscape plants to a desirable size.