scholarly journals Influence of growth retardant on growth and development of Euphorbia pulcherrima Willd. ex Klotzsch

2014 ◽  
Vol 67 (3) ◽  
pp. 65-74 ◽  
Author(s):  
Anna Pobudkiewicz
Keyword(s):  
Stomatal Conductance ◽  
Growth Inhibition ◽  
Transpiration Rate ◽  
Growth And Development ◽  
Stem Elongation ◽  
Foliar Spray ◽  
Growth Retardant ◽  
Euphorbia Pulcherrima ◽  
Unit Leaf ◽  
Lateral Shoots

This study was undertaken to evaluate the influence of single foliar flurprimidol treatment on morphology and transpiration of ‘Roman’ and ‘Freedom Red’ poinsettias. The growth retardant flurprimidol (Topflor 015 SL) was applied once as a foliar spray at concentrations of 5, 10 or 15 mg × dm<sup>-3 </sup>when lateral shoots were about 5 cm in length. Single foliar flurprimidol treatment was sufficient to inhibit stem elongation of both poinsettia cultivars. The degree of growth inhibition depended on cultivar and growth retardant concentration. As compared to the control, the shoots of flurprimidol treated ‘Roman’ and ‘Freedom Red’ plants were up to 44% and 37% shorter, respectively. The desirable plant heights for ‘Roman’ and ‘Freedom Red’ poinsettias were obtained with flurprimidol at concentrations of 5 and 10 mg × dm<sup>-3</sup>, respectively. The shoots of flurprimidol sprayed poinsettia were also more rigid and aligned relative to each other and thus the bracts on the plant were placed on the same level. The diameters of growth retardant treated poinsettias were up to 13% narrower. The leaf areas, petiole lengths, fresh and dry weights of ‘Roman’ and ‘Freedom Red’ poinsettias treated with flurprimidol were substantially smaller as compared to the control. The bract diameters of both poinsettia cultivars were only slightly affected by growth retardant application. Plants exposed to flurprimidol had also intensified green leaf pigmentation. There was almost no abscission of the oldest leaves in the low portions of growth retardant treated plants, compared to those of the control ones. Flurprimidol had no effect on transpiration rate per unit leaf area and stomatal conductance in both poinsettia cultivars. No phytotoxicity was observed in flurprimidol treated plants. Chemical name used: α-(1-methylethyl)-α-[4-(trifluromethoxy)phenyl]-5-pyrimidinemethanol (flurprimidol).

scholarly journals Controlling Poinsettia (Euphorbia pulcherrima Will.) Height with Growth Retardant Application in West Java, Indonesia

2016 ◽  
Vol 3 (3) ◽  
pp. 89-92
Author(s):  
Dewi Sukma ◽  
Gina Megawati
Keyword(s):  
Plant Height ◽  
Growth And Development ◽  
Leaf Size ◽  
Flowering Plants ◽  
Growth Retardant ◽  
Euphorbia Pulcherrima ◽  
West Java ◽  
Internodal Length ◽  
Potted Plant ◽  
Plant Shoots

A study was conducted to evaluate the effects of the growth retardant Cycocel application in the growth and development of poinsettia (Euphorbia pulcherrima) ‘Freedom Red’.  Cycocel was applied by spraying plant shoots at the concentrations of 1000, 1500, 2000, 2500 ppm. The increase in cycocel concentrations reduced plant height, leaf size, internodal length, plant spread and the number of flowering plants. All cycocel concentrations resulted in an ideal potted plant height. The optimum spray concentration of Cycocel used to obtain compact and uniformly flowering plants under tropical West Java environment was 1000 ppm.

Effects of Coppicing on Growth Rates, Stomatal Characteristics and Water Relations in Eucalyptus camaldulensis Dehn

1980 ◽  
Vol 7 (1) ◽  
pp. 81 ◽  
Author(s):  
T.J Blake
Keyword(s):  
Transpiration Rate ◽  
Stem Elongation ◽  
Eucalyptus Camaldulensis ◽  
Fold Increase ◽  
Lower Surface ◽  
Stomatal Resistance ◽  
Stomatal Characteristics ◽  
Unit Leaf ◽  
Diffusive Resistance ◽  
Stomatal Length

Stem elongation, transpiration rate, water potential, diffusive resistance and stomatal characteristics were compared in intact and coppiced (decapitated) seedlings of E. camaldulensis. Stump sprouts from coppiced seedlings showed a threefold increase in the rate of stem elongation, a doubling in transpiration rate per seedling and a 5–8-fold increase in transpiration per unit leaf area compared with intact seedlings. Reversion to more juvenile leaf morphology following decapitation was accompanied by decrease in leaf stomatal resistance. Increased stomatal length and higher stomatal frequency on the lower surface of coppice leaves appears to explain the increased transpiration rate following decapitation compared with intact seedlings.

scholarly journals Early Flurprimidol Drench Applications Suppress Final Height of Four Poinsettia Cultivars

2011 ◽  
Vol 21 (1) ◽  
pp. 35-40 ◽  
Author(s):  
Christopher J. Currey ◽  
Roberto G. Lopez
Keyword(s):  
Stem Elongation ◽  
Final Height ◽  
Foliar Spray ◽  
Euphorbia Pulcherrima ◽  
Growth Retardants ◽  
Height Ratio ◽  
Chlormequat Chloride ◽  
Area Index ◽  
Aesthetic Appearance ◽  
Plant Growth Retardants

Plant growth retardants (PGRs) are commonly applied to control poinsettia (Euphorbia pulcherrima) stem elongation to meet a target final height. Two weeks after pinching, 4-fl·oz substrate drenches containing 0.0, 0.05, 0.10, 0.15, 0.20, or 0.25 mg·L−1 flurprimidol were applied to high-vigor ‘Orion’ and low-vigor ‘Polly Pink’ poinsettia (Expt. I); while drenches containing 0.0, 0.05, 0.10, or 0.15 mg·L−1 flurprimidol or a foliar spray containing 1250 mg·L−1 daminozide and 750 mg·L−1 chlormequat chloride were applied to high-vigor ‘Classic Red’ and low-vigor ‘Freedom Salmon’ poinsettia (Expt. II). Final height of ‘Orion’ and ‘Polly's Pink’ poinsettia was suppressed by 12% to 25% and 13% to 30%, respectively, as flurprimidol concentration increased from 0.05 to 0.25 mg·L−1. Final height of ‘Classic Red’ and ‘Freedom Salmon’ was suppressed by 11% to 30% and 10% to 19%, respectively, as flurprimidol concentration increased from 0.05 to 0.15 mg·L−1. Although the daminozide and chlormequat chloride spray had no significant effect on bract area index compared with untreated plants, bract area index was smaller for all plants treated with flurprimidol. However, the bract area to height ratio of all cultivars was not impacted by any PGR application, indicating aesthetic appearance was not negatively affected with smaller bract area. Time to anthesis was delayed by up to 4 days when 0.10 mg·L−1 was applied to ‘Classic Red’, although no significant delays were observed for the remaining cultivars. Based on these results, flurprimidol may be applied as an early drench to suppress height of poinsettia without adversely impacting finished plant quality or crop timing.

scholarly journals Effects of GA3 on Poinsettia Over-retarded with Paclobutrazol

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 822D-822
Author(s):  
Amy D. McDaniel* ◽  
Yin-Tung Wang
Keyword(s):  
Stem Elongation ◽  
Foliar Spray ◽  
Euphorbia Pulcherrima ◽  
Excellent Quality ◽  
Short Days

A study was initiated to determine the effect of GA3 as a counter measure to restore the growth of over-retarded poinsettia. Euphorbia pulcherrima `Sonora Red' plants were treated once foliarly with paclobutrazol at 40 or 80 mg·L-1 one week following pinching. Four weeks later, plants receiving the 80 mg·L-1 rate were treated once foliarly with GA3 at 0, 10, 20, 30 or 40 mg·L-1. The effect of GA3 was visible within 3 days of application. GA3 between 10 and 40 mg·L-1 caused long internodes, excessive stem elongation, as well as small leaves and bracts, resulting in unmarketable plants. Plants receiving 10 mg·L-1 GA3 were nearly twice the height of the over-retarded plants (31 vs. 17 cm), with increasingly taller plants at higher concentrations, up to 30 mg·L-1. In a second experiment, single-stemed plants were treated with one foliar spray of 50 or 150 mg·L-1 paclobutrazol two weeks following the beginning of short days. After another 3 weeks, the overdosed plants were then foliarly treated once with 0, 3, 5, 10, or 15 mg·L-1 GA3. GA3 at all rates promoted stem elongation and resulted in large bracts and much increased inflorescence diameter. The 15 mg·L-1 GA3 rate resulted in undesirable long internodes on the upper stem. Plants that received 3, 5, or 10 mg·L-1 GA3 were of excellent quality, with their heights and inflorescence sizes similar to those of plants receiving 50 mg·L-1 paclobutrazol (26 cm). Parallel experiments using `Burgundy Cortez' had similar results.

scholarly journals Growth and Development of Euphorbia pulcherrima `Freedom' and Lilium longiflorum `Nellie White' in Sphagnum Peat- and Coir Dust-based Substrates

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 657a-657
Author(s):  
Andrew A. Waber ◽  
Michael R. Evans
Keyword(s):  
Growth And Development ◽  
Lilium Longiflorum ◽  
Euphorbia Pulcherrima ◽  
Fresh Weight ◽  
Shoot Fresh Weight ◽  
Sphagnum Peat ◽  
Lateral Shoots ◽  
Coir Dust

Euphorbia pulcherrima `Freedom' (poinsettia) were grown in coir dust, sphagnum peat, and perlite at the following ratios (respectively) 20:0:80, 40:0:60, 60:0:40, 80:0:20, 0:20:80, 0:40:60, 0:60:40, and 0:80:20 (v/v) substrates. Days to anthesis were not significantly different between substrates. Heights were greater for plants produced in 80% coir compared to plants grown in 80% peat. Overall, plants grown in coir-based substrates were taller than plants grown in peat-based substrates. Plants grown in 60% coir had a greater number of lateral shoots, increased shoot fresh weight and increased bract area compared to plants grown in 60% peat. Overall, plants grown in coir-based substrates had greater shoot fresh weights compared to plants grown in peat-based substrates. Lilium longiflorum `Nellie White' (lily) plants were grown in 40:0:20:40, 0:40:20:40, 0:57:14:28, 0:73:9:18 (v/v sphagnum peat: coir dust: loam: perlite) substrates. As the proportion of coir in the substrate increased, height, and shoot and root fresh weights increased. Nodes to flower, days to flower, and number of flowers were not significantly affected by substrate.

scholarly journals Foliar Sprays of Flurprimidol, Paclobutrazol, and Uniconazole Suppress Height of Seed-propagated New Guinea Impatiens

2016 ◽  
Vol 26 (1) ◽  
pp. 20-25
Author(s):  
Christopher J. Currey ◽  
Nicholas J. Flax ◽  
Kellie J. Walters
Keyword(s):  
Plant Height ◽  
Growth And Development ◽  
Stem Elongation ◽  
New Guinea ◽  
Growth Retardant ◽  
Deionized Water ◽  
Water Control ◽  
Chlormequat Chloride ◽  
Impatiens Hawkeri ◽  
New Guinea Impatiens

Our objective was to quantify the efficacy of foliar plant growth retardant applications on plant height and time to flower of seed-propagated new guinea impatiens (Impatiens hawkeri) produced in packs and flats. ‘Divine Cherry Red’, ‘Divine Scarlet Bronze Leaf’, and ‘Divine White Blush’ seedlings were planted in 1801-cell packs. Seven days after planting, deionized water (control) or solutions containing ancymidol (15 to 60 mg·L−1), chlormequat chloride (750 to 3000 mg·L−1), daminozide (1250 to 5000 mg·L−1), ethephon (250 to 1000 mg·L−1), flurprimidol (10 to 40 mg·L−1), paclobutrazol (10 to 40 mg·L−1), or uniconazole (5 to 20 mg·L−1) were applied to seedlings. A second experiment was performed with the same cultivars quantifying the growth and development in response to a broader range of flurprimidol or paclobutrazol (5 to 40 mg·L−1) or uniconazole (2.5 to 20 mg·L−1) sprays. Plant height was measured 7 weeks after planting. For Expt. 1, ancymidol, chlormequat chloride, and daminozide had little to no impact on stem elongation. However, flurprimidol, paclobutrazol, and uniconazole suppressed height at flowering of all three cultivars. In Expt. 2, plant height with concentrations flurprimidol, paclobutrazol, or uniconazole up to 27 to 30, 20 to 30, or 4 to 5 mg·L−1, respectively, depending on the cultivar. Five to 20 mg·L−1 flurprimidol or paclobutrazol, or < 2.5 mg·L−1 uniconazole may be used to control stem elongation of seed-propagated new guinea impatiens for production in flats.

scholarly journals Photosynthetic characteristics in fig tree accessions for diversification of production

2019 ◽  
Vol 13 ◽  
pp. 268
Author(s):  
Lucas Ferreira ◽  
Maria Gabriela Fontanetti Rodrigues ◽  
Lucas Aparecido Manzani Lisboa ◽  
Abimael Gomes Da Silva ◽  
Arlindo Ananias Pereira da Silva ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Transpiration Rate ◽  
Growth And Development ◽  
Co2 Assimilation ◽  
Leaf Temperature ◽  
Physiological Characteristics ◽  
Physiological Variables ◽  
Metabolic Reactions ◽  
Fig Tree ◽  
Production Characteristics

Photosynthesis allows plants, through metabolic reactions, to obtain products for their growth and development. Knowledge of and estimating the physiological variables involved in the photosynthetic process can be an advantage in choosing accessions for setting up an orchard. The aim of this study therefore was to evaluate some of the physiological characteristics involved in the photosynthetic process of six commercial accessions of the fig tree. The experiment was conducted in a completely randomised design, comprising six treatments and six replications, giving a total of 36 experimental units. The treatments consisted of the following fig accessions: ‘Roxo de Valinhos’, ‘Palestino’, ‘Figo Vermelho’, ‘PI 189’, ‘Cuello Negro’ and ‘Turco’. The net rate of CO2 assimilation, stomatal conductance, transpiration rate and internal leaf temperature varied statistically between accessions. Some accessions demonstrated the same performance as ‘Roxo de Valinhos’ for the photosynthetic variables. As such, the dependence of the domestic market on one single cultivar should be reviewed; however, further studies on other physiological and production characteristics should be carried out in order to validate each recommendation.

The Effects of Drought on Leaf Gas Exchange and Growth of Three Species of Herbaceous Perennials

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 540a-540
Author(s):  
K.J. Prevete ◽  
R.T. Fernandez
Keyword(s):  
Drought Stress ◽  
Stomatal Conductance ◽  
Gas Exchange ◽  
Drought Tolerance ◽  
Transpiration Rate ◽  
Leaf Gas Exchange ◽  
Gas Analysis ◽  
Herbaceous Perennials ◽  
Effects Of Drought ◽  
Analysis System

Three species of herbaceous perennials were tested on their ability to withstand and recover from drought stress periods of 2, 4, and 6 days. Eupatorium rugosum and Boltonia asteroides `Snowbank' were chosen because of their reported drought intolerance, while Rudbeckia triloba was chosen based on its reported drought tolerance. Drought stress began on 19 Sept. 1997. Plants were transplanted into the field the day following the end of each stress period. The effects of drought on transpiration rate, stomatal conductance, and net photosynthetic rate were measured during the stress and throughout recovery using an infrared gas analysis system. Leaf gas exchange measurements were taken through recovery until there were no differences between the stressed plants and the control plants. Transpiration, stomatal conductance, and photosynthesis of Rudbeckia and Boltonia were not affected until 4 days after the start of stress. Transpiration of Eupatorium decreased after 3 days of stress. After rewatering, leaf gas exchange of Boltonia and Rudbeckia returned to non-stressed levels quicker than Eupatorium. Growth measurements were taken every other day during stress, and then weekly following transplanting. Measurements were taken until a killing frost that occurred on 3 Nov. There were no differences in the growth between the stressed and non-stressed plants in any of the species. Plants will be monitored throughout the winter, spring, and summer to determine the effects of drought on overwintering capability and regrowth.

scholarly journals Response of in vitro Cultured Palm Oil Seedling Under Saline Condition to Elevated Carbon Dioxide and Photosynthetic Photon Flux Density

2012 ◽  
pp. 52-64
Author(s):  
Pet Roey Pascual ◽  
Krienkai Mosaleeyanon ◽  
Kanokwan Romyanon ◽  
Chalermpol Kirdmanee
Keyword(s):  
Stomatal Conductance ◽  
Net Photosynthetic Rate ◽  
Elevated Co2 ◽  
Photosynthetic Rate ◽  
Transpiration Rate ◽  
Pigment Contents ◽  
Salinity Levels ◽  
Oil Palms ◽  
Ambient Co2

Salt stress elicits various physiological and growth responses of oil palm. A laboratory experiment was conducted to determine the responses of oil palms cultured in vitro under varying salinity levels (0, 85.5, 171.11, 342.21 and 684.43 mM NaCl) to elevated CO2 (1000 μmol CO2/mol) and PPFD (100±5 μmol m-2s-1) in terms of growth characteristics, pigment contents and photosynthetic abilities. After 14 days of culture, net photosynthetic rate (μmol CO2 m-2s-1) of oil palms across varying salinity levels was 5.33 times higher than those cultured under ambient CO, (380±100 Mmol CO2/mol) and PPFD (50±5 μmol m-2s -1). At increased net photosynthetic rate (elevated CO2 and PPFD), despite having no significant difference in pigment contents (chlorophyll a, chlorophyll b, total chlorophyll and carotenoid) between different CO2 and PPFD levels, dry weight and percent dry matter were 0.26 and 0.11 times higher, respectively, as compared to those cultured under ambient CO2 and PPFD. In the same elevated CO2 and PPFD level, across all salinity levels, stomatal conductance was 0.30 times lower than those cultured under ambient CO2 and PPFD. At reduced stomatal conductance (elevated CO2 and PPFD), transpiration rate was also reduced by 0.30 times. Thus with increased net photosynthetic rate and reduced transpiration rate, water use efficiency was increased by 7.22 times, across all salinity levels, than those cultured at ambient CO2 and PPFD. These were considered essential for NaCl produces iso-osmotic stress.

scholarly journals Patatesin Kısa Süreli Kuraklık Uygulamasına Fizyolojik Tepkileri

2016 ◽  
Vol 4 (7) ◽  
pp. 618
Author(s):  
İlknur Tındaş ◽  
Ufuk Demirel
Keyword(s):  
Stomatal Conductance ◽  
Photosynthetic Rate ◽  
Transpiration Rate ◽  
Tuber Yield ◽  
Russet Burbank ◽  
Significant Decline ◽  
Proline Content ◽  
Drought Treatment ◽  
H2o2 Accumulation ◽  
Tuber Bulking

The study aimed to identify physiological response of potato to drought. For this aim, a drought experiment was carried out by using two different potato varieties, cv. Desiree and Russet Burbank, under environmentally controlled greenhouse conditions. Drought treatment was initiated at 45 days after emergence (early tuber bulking period) by withholding irrigation for 10 days. Physiological traits such as stomatal conductance, transpiration rate, photosynthetic rate, chlorophyll index, leaf temperature, proline content, malondialdehyde (MDA) accumulation and hydrogen peroxide (H2O2) accumulation, in addition, some yield components average tuber weight, number of tubers and plant tuber yield were evaluated in the study. While the first significant decline in stomatal conductance, transpiration rate, and photosynthetic rate of both varieties was occurred at the 5th day of withholding irrigation, the highest decline was observed at 9th and 10th days of withholding irrigation. Proline content in both varieties increased two times at 10th day of withholding irrigation, however, H2O2 accumulation was not changed significantly by drought treatment. Even though MDA accumulation was increased in both varieties under drought stress conditions, the increase was significant in Desiree whereas, it was not significant in Russet Burbank. In addition, while drought treatment did not change the plant tuber yield in both varieties, it caused to a significant decline in average tuber yield of Russet Burbank, being an important trait for marketable tuber yield.

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