scholarly journals 294 Quantifying the Effect of Application Date of Paclobutrazol Drenches on Poinsettia Stem Elongation and Bract Size

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 493B-493
Author(s):  
Pamela Korczynski ◽  
James E. Faust ◽  
Robert Klein
Keyword(s):  
Plant Height ◽  
Stem Elongation ◽  
Internode Length ◽  
Node Number ◽  
Application Date

Paclobutrazol drenches (1 ppm, 118.4 mL per pot) were applied to Poinsettia `Freedom' Red' on 1, 11, 21, and 31 Oct. in 1997 and 1998. Plant heights were recorded twice weekly throughout the experiment, and internode length and bract area were measured at harvest. The total bract area of the three true bracts and the top three transitional bracts was reduced by 5.8%, 13.6%, 4.2%, and 2.3% for the 1, 11, 21, and 31 Oct. application dates, respectively; however, all plants were highly marketable. At the time of each drench application, the most newly unfolded leaf was marked. The internode lengths for the three internodes below this leaf and the internodes that developed after the drench application were typically between 5 and 10 mm in length, while the internode lengths of the control plants were typically 10 to 25 mm, depending on node number. Plant height increased 62, 51, 47 and 19 mm following application on the 1, 11, 21, and 31 Oct. application dates, respectively. The 1, 11, 21, and 31 Oct. drench applications reduced total stem elongation from 1 Oct. to anthesis by 64%, 49%, 28%, and 15%, respectively. Paclobutrazol drenches did not affect time to anthesis.

scholarly journals Effects of Paclobutrazol Drench Application Date on Poinsettia Height and Flowering

2001 ◽  
Vol 11 (4) ◽  
pp. 557-560 ◽  
Author(s):  
James E. Faust ◽  
Pamela C. Korczynski ◽  
Robert Klein
Keyword(s):  
Plant Height ◽  
Stem Elongation ◽  
Internode Length ◽  
Euphorbia Pulcherrima ◽  
Late Season ◽  
Area Reduction ◽  
Length Measurements ◽  
Application Date ◽  
Long Term Impact

Experiments were conducted to evaluate the effects of paclobutrazol drenches on poinsettia (Euphorbia pulcherrima) `Freedom Red' height and flowering. In 1997 and 1998, paclobutrazol drenches [(a.i.) 0.118 mg/container; (28,350 mg = 1.0 oz)] were applied to poinsettias grown under natural photoperiods on four dates from 1 Oct. to 2 Nov. On plants receiving the paclobutrazol drench application during the second week in October, bract area was reduced by 15% and 12% compared with that of the control in 1997 and 1998, respectively; however, the bract area reduction was commercially acceptable. Anthesis date was not significantly affected during either year. Plant height and internode length measurements indicate that paclobutrazol drench applications had both a rapid and a long-term impact on poinsettia stem elongation. Paclobutrazol drenches applied in late October or early November are an effective tool for controlling late-season stem elongation of `Freedom Red' poinsettias grown under natural photoperiods. These late-season applications have the least risk for negatively affecting bract size while still reducing stem elongation in the last few weeks of the crop. Chemical names used: (±)-(R*,R*)-b-[(chlorophenyl)methyl]-a-(1,1-dimethyl)-1H-1,2,4-triazole-1-ethanol (paclobutrazol).

scholarly journals Controlling Height with Temperature

1998 ◽  
Vol 8 (4) ◽  
pp. 535-539 ◽  
Author(s):  
Robert Berghage
Keyword(s):  
Plant Height ◽  
Production Systems ◽  
Formation Rate ◽  
Internode Length ◽  
Temperature Management ◽  
Night Temperature ◽  
Greenhouse Production ◽  
Node Number ◽  
Height Control ◽  
Average Temperature

Temperature management has emerged as an important tool for plant height control in greenhouse production systems. This is particularly important in vegetable transplant production where chemical controls for plant height are limited or not legal. Plant height is a function of the number of nodes and the length of each internode, and both are strongly influenced by greenhouse temperatures. Node number, or formation rate, is primarily a function of the average greenhouse temperature, increasing as the average temperature increases. Internode length is strongly influenced by the relationship between the day and night temperature, commonly referred to as DIF (day temperature - night temperature). As DIF increases, so does internode length in most plant species studied. Although the nature and magnitude of temperature effects vary with species, cultivar, and environmental conditions, these two basic responses can be used to modify transplant growth. Although data are limited, controlling transplant height with temperature does not appear to adversely influence plant establishment or subsequent yield.

scholarly journals 630 Growth Regulators Affect the Morphology and Flowering of Argyranthemum, Calibrachoa, and Orthosiphon

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 506B-506
Author(s):  
Hope K. Onken ◽  
Terri W. Starman
Keyword(s):  
Plant Height ◽  
Foliar Spray ◽  
Internode Length ◽  
Stem Length ◽  
Internode Elongation ◽  
Flower Number ◽  
Node Number ◽  
New Crops ◽  
Pedicle Length ◽  
Plant Form

Argyranthemum frutescens `Sugar Baby', Calibrachoa hybrid `Million Bells Cherry Pink', and Orthosiphon stamineus `Lavender' are three vegetatively propagated specialty annuals that are recent introductions into the floriculture industry. It is important to understand how the growth and development of these new crops is best controlled. Rooted cuttings of these three species where transplanted into 10-cm pots on 7 Oct. and the plant growth regulator treatments were applied on 19 Oct. 1999. Foliar spray treatments included ancymidol at 66 and 132, daminozide at 2500 and 5000, paclobutrazol at 20 and 40, ethephon at 500 and 1000, and uniconazole at 10 and 20 mg/L. Uniconazole medium drench treatment was applied at 1 and 2 mg/L. Control was a water foliar spray. At harvest, plant height, plant width, number of flowers, pedicle length, stem length, stem node number and internode length, and fresh and dry weights were measured. Uniconazole spray at 20 mg/L reduced plant height and width without affecting the fresh and dry weights of Argyranthemum. Flower number was increased and pedicel length was reduced. The overall plant height and width of Calibrachoa were not reduced with 20 mg /L uniconazole foliar spray, but plant form was improved by decreased internode elongation. Uniconazole foliar spray at 20 mg/L reduced Orthosiphon stem and internode length. Ethephon reduced plant height, plant width, and flower number of all species. Branching and days to flower were increased in Orthosiphon. In all species, daminozide and paclobutrazol were found to be ineffective, while ancymidol spray and uniconazole drench stunted and distorted growth.

scholarly journals Study on the Regulatory Effects of GA3 on Soybean Internode Elongation

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1737
Author(s):  
Fuxin Shan ◽  
Rui Zhang ◽  
Jin Zhang ◽  
Chang Wang ◽  
Xiaochen Lyu ◽  
...  
Keyword(s):  
Plant Height ◽  
Apical Meristem ◽  
Stem Elongation ◽  
Internode Length ◽  
Internode Elongation ◽  
Primary Xylem ◽  
Dwarf Cultivar ◽  
Leaves And Roots ◽  
Soybean Plants ◽  
Regulatory Effects

Excessive plant height is an important factor that can lead to lodging, which is closely related to soybean yield. Gibberellins are widely used as plant growth regulators in agricultural production. Gibberellic acid (GA3), one of the most effective active gibberellins, has been used to regulate plant height and increase yields. The mechanism through which GA3 regulates internode elongation has been extensively investigated. In 2019 and 2020, we applied GA3 to the stems, leaves, and roots of two soybean cultivars, Heinong 48 (a high-stalk cultivar) and Henong 60 (a dwarf cultivar), and GA3 was also applied to plants whose apical meristem was removed or to girded plants to compare the internode length and stem GA3 content of soybean plants under different treatments. These results suggested that the application of GA3 to the stems, leaves, and roots of soybean increased the internode length and GA3 content in the stems. Application of GA3 decreased the proportion of the pith in the soybean stems and primary xylem while increasing the proportion of secondary xylem. The apical meristem is an important site of GA3 synthesis in soybean stems and is involved in the regulation of stem elongation. GA3 was shown to be transported acropetally through the xylem and laterally between the xylem and phloem in soybean stems. We conclude that the GA3 level in stems is an important factor affecting internode elongation.

scholarly journals Interactive Effects of Nitrogen and Sulfur Nutrition on Growth, Development, and Physiology of Brassica carinata A. Braun and Brassica napus L.

2021 ◽  
Vol 13 (13) ◽  
pp. 7355
Author(s):  
Shivendra Kumar ◽  
Ramdeo Seepaul ◽  
Ian M. Small ◽  
Sheeja George ◽  
George Kelly O’Brien ◽  
...  
Keyword(s):  
Electron Transport ◽  
Leaf Area ◽  
Photosynthetic Pigments ◽  
Net Photosynthesis ◽  
Brassica Carinata ◽  
Internode Length ◽  
Erucic Acid Content ◽  
Total Biomass ◽  
Node Number ◽  
S 100

Brassica carinata (carinata) has emerged as a potential biofuel source due to its high erucic acid content, making it desirable for various industrial applications. Nitrogen (N) and sulfur (S) are required as primary sources of nutrition for growth and development in different oilseed crops and their utilization is interdependent. The purpose of the study was to analyze the interactive effect of N and S nutrition on the growth and other physiological activities of carinata and B. napus (napus). Four treatments, i.e., optimum NS (+N+S, 100% N and 100% S); N limited (−N+S, 0% N, 100% S); S limited (+N−S, 100% N, 0% S), and NS limited (−N−S, 0% N and 0% S) of N and S in full-strength Hoagland solution were imposed in the current study. Effect of different NS treatments was observed on vegetative traits such as number of primary and secondary branches, total leaf area, total biomass production and allocation, and physiological traits such as production of photosynthetic pigments, net photosynthesis, electron transport, and other aspects for both carinata and napus. The traits of stem elongation, number of nodes, node addition rate, internode length, number of primary and secondary branches were 60%, 36%, 50%, 35%, 56%, and 83% lower, respectively, in napus in comparison to carinata. Different NS treatments also positively influenced the production of photosynthetic pigments such as chlorophyll (Chl) a and b and carotenoids in carinata and napus. The concentration of Chla was 11% higher in napus in comparison to carinata. The rate of net photosynthesis, electron transport, and fluorescence was 12%, 8%, and 5% higher based on overall value, respectively, in napus compared to carinata. On the other hand, the overall value for stomatal conductance decreased by 5% in napus when compared to carinata. Different growth-related traits such as vegetative (plant height, node number, internode length, leaf area, number of primary and secondary branches), reproductive (pod number, pod length, seeds per pod), and photosynthetic capacity in oilseed brassicas are correlated with the final seed and oil yield and chemical composition which are of economic importance for the adoption of the crop. Thus, the analysis of these traits will help to determine the effect of NS interaction on crop productivity of carinata and napus.

scholarly journals Response of Oxypetalum caeruleum to Irradiance, Temperature, and Photoperiod

1990 ◽  
Vol 115 (6) ◽  
pp. 910-914 ◽  
Author(s):  
A.M. Armitage ◽  
N.G. Seager ◽  
I.J. Warrington ◽  
D.H. Greer ◽  
J. Reyngoud
Keyword(s):  
Stem Elongation ◽  
Net Photosynthesis ◽  
Stem Length ◽  
Photon Flux ◽  
Vase Life ◽  
Photosynthetic Photon Flux ◽  
Node Number ◽  
Stem Strength ◽  
Flower Abortion ◽  
Reduced Time

Incremental increases in temperature from 14 to 22 to 30C resulted in linear increases in stem length and node number and decreases in stem diameter and stem strength of Oxypetalum caeruleum (D. Don.) Decne. Higher temperatures also resulted in additional flower abortion, reduced time to flowering, and fewer flowering stems per inflorescence. Reduction in the photosynthetic photon flux (PPF) from 695 to 315 μmol·s-1·m-2 had similar effects as increasing the temperature on vegetative characteristics, but had little effect on reproductive ones. The rate of stem elongation was greatest at low PPF for all temperatures and at high temperature for all PPF treatments. Net photosynthesis rose between 14 and 22C and declined at 30C for all PPF treatments. Long photoperiods (12 or 14 hours) resulted in longer internodes, longer stems, and more flowers per cyme than short photoperiods (8 or 10 hours), but photoperiod had little effect on flowering time. Treatments to reduce latex coagulant and silver thiosulfate treatments had no significant effect on vase life.

scholarly journals Carbohydrate reserve and aerenchyma formation enhance submergence tolerance in rice

2016 ◽  
Vol 27 (3) ◽  
pp. 256-264
Author(s):  
MHR Pramanik ◽  
IJ Shelley ◽  
D Adhikary ◽  
MO Islam
Keyword(s):  
Plant Height ◽  
Stem Elongation ◽  
Normal Growth ◽  
Anatomical Structure ◽  
Aromatic Rice ◽  
Submergence Tolerance ◽  
Aerenchyma Formation ◽  
Rice Varieties ◽  
Carbohydrate Reserve ◽  
And Control

An attempt was made to evaluate the submergence tolerance in rice using four Aman rice varieties viz. FR13A (local flood resistant, check), BRRI dhan 51 (HYV flood tolerant, check), BR 5 (HYV, susceptible) and a local aromatic rice,Ukunimadhu (local susceptible). Twenty  days old seedlings of the rice varieties raised in earthen pots were submerged under 90 cm water depth in a submergence tank for 12 days and data were recorded on plant height, tiller number, carbohydrate reserve and internal anatomical structure of roots of the submerged and control (ambient) plants. Under submergence treatment Ukunimadhu showed rapid stem elongation with taller plants than the HYVs which showed shorter plant height. Tillering pattern was almost similar both in submergence treated and control plants in all the varieties. Variation in carbohydrate reserve was negligible among the varieties at ambient condition but the submergence treatment brought significant variation in carbohydrate content in them. Submergence treated FR13A and BRRI dhan 51 had the highest sugar and starch conservation ability while BR 5 and Ukunimadhu had the lowest. The higher reserved carbohydrate in the tolerant varieties might assist them to regenerate their normal growth rapidly after desubmergence. The cellular morphology of root tissue showed that intensity of aerenchyma development in submergence treated FR13A and BRRI dhan 51 was more pronounced compared to the local aromatic rice Ukunimadhu and perhaps this cellular large aerenchymatous development might be associated with the submergence tolerance of FR13A and BRRI dhan 51 than the local variety, Ukunimadhu.Progressive Agriculture 27 (3): 256-264, 2016

Effectiveness of paclobutrazol in retarding height growth of Eucalyptusglobulus seedlings

1990 ◽  
Vol 20 (11) ◽  
pp. 1811-1813 ◽  
Author(s):  
S. Hetherington ◽  
K. M. Jones
Keyword(s):  
Plant Height ◽  
Height Growth ◽  
Growth Retardant ◽  
Internode Length ◽  
Pronounced Effect ◽  
Single Application ◽  
Reduced Height

Foliar applications of paclobutrazol significantly reduced height growth and internode length in Eucalyptusglobulus Labill. seedlings. Monthly applications of 125 or 500 mg/L had a more pronounced effect than one single application of 125, 500, or 2000 mg/L. The greatest reduction in plant height was achieved by applying 500 mg/L at monthly intervals over 5 months. Two months after this treatment was ceased the growth retardant effects persisted.

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