Environmental Control of Flowering and Growth of Lysimachia congestiflora Hemsl.

Dense-flowered loosestrife is a quantitative long-day (LD) plant. Plants given a LD photoperiod (16 hours) flowered 21 and 34 days earlier than plants given 12- and 8-hour photoperiods, respectively. Plants under LDs produced significantly more flowers than those under 8- and 12-hour photoperiods. Only 1 week of LD was needed for 100% flowering; however, optimum flower count and size were produced with 3 weeks of LD. Plant dry weight did not differ significantly among treatments; however, LDs produced fewer but larger leaves, particularly those subtending the inflorescence. Total plant growth increased as temperature increased, but lower temperature (10C) decreased flower initiation and prevented flower development. High temperature (26C) reduced the persistence of open flowers. The optimum temperature for dense-flowered loosestrife growth was ≈20C. Flowering was accelerated and dry weight production increased as irradiance levels increased from 100 to 300 μmol·m–2·s–1.

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763 PB 307 ENVIRONMENTAL CONTROL ON FLOWERING AND GROWTH OF LYSIMACHIA CONGESTIFLORA

HortScience ◽

10.21273/hortsci.29.5.542c ◽

1994 ◽

Vol 29 (5) ◽

pp. 542c-542

Author(s):

Donglin Zhang ◽

Allan M. Armitage ◽

James M. Affolter ◽

Michael A. Dirr

Keyword(s):

Environmental Control ◽

Day Treatment ◽

Dry Weight ◽

High Irradiance ◽

Flower Initiation ◽

Low Light ◽

The North ◽

Long Day ◽

Total Plant ◽

Lower Temperature

Lysimachia congestiflora Wils. (Primulaceae) is a new crop for American nurseries and may be used as an annual in the north and a half-hardy perennial in the south. The purpose of this study was to investigate the influence of photoperiod, temperature, and irradiance on its flowering and growth. Three experiments were conducted with photoperiod of 8, 12, 16 hrs day-1, temperature of 10, 18, 26C, and irradiance of 100, 200, 300 μmol m-2s-1, respectively. Plant.9 given long day photoperiod (16 hours) flowered 21 and 34 days earlier, respectively, than plants at 12 sad 8 hour photoperiods. Plants under long day treatment produced more flowers than those at 8 and 12 hours. Plant dry weight did not differ between treatments, but plants grown in the long day treatment produced fewer but larger leaves. Total plant growth increased as temperature increased, but lower temperature (10C) decreased flower initiation and prevented flower development, while high temperature (26C) reduced the longevity of the open flowers. Flowering was accelerated and dry weight increased as plants were subjected to high irradiance levels. The results suggest that Lysimachia congestiflora is a quantitative long day plant. It should be grown under a photoperiod of at least 12 hours at a temperature of approximately 20C. Low light areas should be avoided and supplemental lighting to provide the long days may improve the plant quality.

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Photoperiod, Irradiance, and Temperature Influence Flowering of Hamelia patens (Texas Firebush)

HortScience ◽

10.21273/hortsci.30.2.255 ◽

1995 ◽

Vol 30 (2) ◽

pp. 255-256 ◽

Cited By ~ 2

Author(s):

Allan M. Armitage

Keyword(s):

High Temperature ◽

Flower Development ◽

Dry Weight ◽

Flower Initiation ◽

Temperature Influence ◽

Light Conditions ◽

Low Light ◽

Long Day ◽

Critical Photoperiod ◽

Moderately High Temperature

Hamelia patens Jacq. (Texas firebush) is a long-day plant for flower initiation and flower development; however, flower development is more sensitive to photoperiod than is flower initiation. The critical photoperiod for flower development at 25C is between 12 and 16 hours. Flowering was delayed under low light conditions, and plant dry weight was heavier and flowering time was earlier for plants grown at a constant 25 or 30C than at 20C. A greenhouse environment with a 16-hour photoperiod and moderately high temperature (25C) would be appropriate for production of H. patens.

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Photocontrol of Flowering and Extension Growth in the Long-day Plant Pansy

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.128.4.0479 ◽

2003 ◽

Vol 128 (4) ◽

pp. 479-485 ◽

Cited By ~ 18

Author(s):

Erik S. Runkle ◽

Royal D. Heins

Keyword(s):

Flower Development ◽

Red Light ◽

Reproductive Development ◽

Extension Growth ◽

Separate Experiment ◽

Flower Initiation ◽

Minimal Extension ◽

Short Day ◽

Long Day ◽

Light Duration

Plastics that selectively reduce the transmission of far-red light (FR, 700 to 800 nm) reduce extension growth of many floricultural crops. However, FR-deficient (FRd) environments delay flowering in some long-day plants (LDPs), including `Crystal Bowl Yellow' pansy (Viola ×wittrockiana Gams). Our objective was to determine if FR light could be added to an otherwise FRd environment to facilitate flowering with minimal extension growth. In one experiment, plants were grown under a 16-hour FRd photoperiod, and FR-rich light was added during portions of the day or night. For comparison, plants were also grown with a 9-hour photoperiod [short-day (SD) control] or under a neutral (N) filter with a 16-hour photoperiod (long day control). Flowering was promoted most (i.e., percent of plants that flowered increased and time to flower decreased) when FR-rich light was added during the entire 16-hour photoperiod, during the last 4 hours of the photoperiod, or during the first or second 4 hours after the end of the photoperiod. In a separate experiment, pansy was grown under an FRd or N filter with a 9-hour photoperiod plus 0, 0.5, 1, 2, or 4 hours of night interruption (NI) lighting that delivered a red (R, 600 to 700 nm) to FR ratio of 0.56 (low), 1.28 (moderate), or 7.29 (high). Under the N filter, the minimum NI duration that increased percent flowering was 2 hours with a moderate or low R:FR and 4 hours with a high R:FR. Under the FRd filter, 2 or 4 hours of NI lighting with a moderate or low R:FR, respectively, was required to increase percent flowering, but a 4-hour NI with a high R:FR failed to promote flowering. Pansy appears to be day-neutral with respect to flower initiation and a quantitative LDP with respect to flower development. The promotion of reproductive development was related linearly to the promotion of extension growth. Therefore, it appears that in LDPs such as pansy, light duration and quality concomitantly promote extension growth and flowering, and cannot readily be separated with lighting strategies.

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Specific Functions of Red, Far Red, and Blue Light in Flowering and Stem Extension of Long-day Plants

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.126.3.275 ◽

2001 ◽

Vol 126 (3) ◽

pp. 275-282 ◽

Cited By ~ 61

Author(s):

Erik S. Runkle ◽

Royal D. Heins

Keyword(s):

Blue Light ◽

Flower Development ◽

Red Light ◽

Wide Band ◽

Extension Growth ◽

Photon Flux ◽

Flower Initiation ◽

Stem Extension ◽

Long Day ◽

Long Day Plants

For many long-day plants (LDP), adding far red light (FR, 700 to 800 nm) to red light (R, 600 to 700 nm) to extend the day or interrupt the night promotes extension growth and flowering. Blue light (B, 400 to 500 nm) independently inhibits extension growth, but its effect on flowering is not well described. Here, we determined how R-, FR-, or B-deficient (Rd, FRd, or Bd, respectively) photoperiods influenced stem extension and flowering in five LDP species: Campanula carpatica Jacq., Coreopsi ×grandiflora Hogg ex Sweet, Lobelia ×speciosa Sweet, Pisum sativum L., and Viola ×wittrockiana Gams. Plants were exposed to Rd, FRd, Bd, or normal (control) 16-hour photoperiods, each of which had a similar photosynthetic (400 to 700 nm) photon flux. Compared with that of the control, the Rd environment promoted extension growth in C. carpatica (by 65%), C. ×grandiflora (by 26%), P. sativum (by 23%), and V. ×wittrockiana (by 31%). The FRd environment suppressed extension growth in C. ×grandiflora (by 21%), P. sativum (by 17%), and V. ×wittrockiana (by 14%). Independent of the R: FR ratio, the Bd environment promoted stem extension (by 10% to 100%) in all species, but there was little or no effect on flowering percentage and time to flower. Extension growth was generally linearly related to the incident wide band (100 nm) R: FR ratio or estimated phytochrome photoequilibrium except when B light was specifically reduced. A high R: FR ratio (i.e., under the FRd filter) delayed flower initiation (but not development) in C. carpatica and C.×grandiflora and inhibited flower development (but not initiation) in V.×wittrockiana. Therefore, B light and the R: FR ratio independently regulate extension growth by varying magnitudes in LDP, and in some species, an FRd environment can suppress flower initiation or development.

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Evaluation of heat tolerance potential in Capsicum annum L. genotypes under heat stress

Advance in Biological Research ◽

10.26855/abr.2020003 ◽

2020 ◽

Vol 1 (1) ◽

pp. 16-22

Author(s):

Mujahid Ali ◽

Muhammad Imran Lodhi ◽

Choudhary Muhammad Ayyub ◽

Zahoor Hussain ◽

Zaid Mustafa ◽

...

Keyword(s):

Heat Stress ◽

High Temperature ◽

Plant Growth ◽

Agronomic Traits ◽

Dry Weight ◽

Threshold Level ◽

High Temperature Stress ◽

Bell Pepper ◽

Collective Effects ◽

Economic Losses

Summer vegetables are severely affected by high temperature above threshold level which ultimately results in serious losses of their production. To cope with these economic losses different strategies had been adopted. The present study was designed to screen out heat tolerant genotypes of bell pepper. For this purpose, experiment was conducted in plant growth room in Institute of Horticultural Sciences, University of Agriculture Faisalabad. Ten genotypes of bell pepper (C1G3, C3G5, C7G4, V6G4, C2-E, C5G4, C43-D, C4G3, C43-A, C2G3) were brought from Ayub Agriculture Research Institute Faisalabad (AARI) and were grown. Heat treatment up to 40 ̊C was given. Data regarding agronomic traits (number of leaves, root length, shoot length, seedling dry weight, seedling fresh weight, electrolyte leakage) and physiological (Stomatal conductance, photosynthetic rate, transpiration rate and water use efficiency) was collected. Proper statistical designs were used to analyze the data. The research findings proved that heat stress significantly affected physiology, morphology and mechanisms of screened genotypes which followed the order for the heat stress as C5G4, C1G3, C2G3, C43-A, C3G5, C43-D, V6G4, C4G3, C43-A and C2G3, respectively. The collective effects of all these changes under high temperature stress resulted in poor plant growth and productivity. On the basis of physical and physiological parameters, genotypes C5G4, C1G3 and C43-A were among the most tolerant group and the most resistant genotypes.

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Application of Photoperiodic Manipulation in Vegetative Specialty Floral Crop Propagation and Flowering

HortScience ◽

10.21273/hortsci.33.3.554d ◽

1998 ◽

Vol 33 (3) ◽

pp. 554d-554

Author(s):

Millie S. Williams ◽

Terri Woods Starman

Keyword(s):

Flowering Time ◽

Flower Development ◽

Vegetative Growth ◽

Plant Production ◽

Flower Initiation ◽

Stock Plant ◽

Flower Number ◽

Open Flower ◽

Long Day ◽

Photoperiodic Responses

Photoperiod requirements are important for optimum flower development, decreasing production time, year-round flowering, and/or for increasing vegetative growth necessary in stock plant production. The photoperiodic responses were determined for 24 vegetatively propagated specialty floral crops. Each plant species was grown at 8-, 10-, 12-, 14-, and 16-h photoperiods. Photoperiods were provided by 8 h of sunlight, then pulling black cloth and providing daylength extension with incandescent bulbs. Data collected included time to flower, flower number, and vegetative characteristics. Evolvulus nuttallianus `Blue Daze', Heliotropium arborescens `Fragrant Delight', and Orthosiphon stamineus `Lavender' were facultative short-day plants with respect to flowering. Time to flower increased as photoperiod increased. Duranta repens `Blue', Verbena hybrid `Tapien Lavender', and Verbena peruviana `Trailing Katie' were facultative long day plants with respect to flowering. Days to visible bud and first open flower decreased as photoperiod increased. Argeranthemum frutescens `Sugar Baby', Scaevola aemula `Fancy Fan Falls', and Portulaca hybrid `Apricot' had increased flower number as photoperiod increased from 8- to 16-h, although time to first flower initiation was not affected. Abutilon hybrid `Apricot', Duranta repens `Blue', Evolvulus nuttallianus `Blue Daze', Lotus berthelotii `Parrot's Beak', Lysimachia nummularia `Aurea Creeping Golden', Rhodanthe anthemoides `Milkyway', and Scaevola aemula `Fancy Fan Falls' had increased vegetative growth as photoperiod increased. All other species studied were day-neutral with regard to flowering and vegetative parameters.

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Influence of Environment on Metabolism of Propanil in Rice

Weed Science ◽

10.1017/s0043174500050529 ◽

1971 ◽

Vol 19 (5) ◽

pp. 501-507 ◽

Cited By ~ 4

Author(s):

Richard H. Hodgson

Keyword(s):

Oryza Sativa ◽

High Temperature ◽

High Growth ◽

Dry Weight ◽

Mean Value ◽

Water Soluble ◽

Day Length ◽

Tissue Mass ◽

Long Day ◽

Root Treatment

The metabolism of 3′,4′-dichloropropionanilide (propanil) to 3,4-dichloroaniline (hereinafter referred to as 3,4-DCA) andN-(3,4-dichlorophenyl)glucosylamine (hereinafter referred to as 3,4-DCAG) was quantitatively modified in rice (Oryza sativaL. ‘Nato’) by temperature and day length. The propanil, 3,4-DCA, and 3,4-DCAG content of rice was determined 1, 2, 5, and 8 days after root treatment with 92 μM propanil. Plants were grown and treated under long-day (16 hr) and short-day (12 hr) conditions with day temperatures of 32, 27, or 21 C and night temperatures of 21 C. Absorption and metabolism of propanil were most rapid under high temperature and long day conditions. A mean value of 0.75 μmoles total of aniline equivalent per plant was obtained. Greater quantities of 3,4-DCA and 3,4-DCAG were recovered from plants in high temperature, long day environments. An average of 47% of the propanil plus water-soluble metabolites in rice was in root tissue. Conditions favoring high growth rates and transpiration increased the percentage in the shoots. Because of the increased tissue mass at high temperatures, mean concentrations of propanil plus water-soluble metabolites in plant tissue were reduced from 0.18 to 0.12 μmoles/g dry weight.

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High Temperature Affects the Activity of Enzymes in the Committed Pathway of Starch Synthesis in Developing Wheat Endosperm

Functional Plant Biology ◽

10.1071/pp9930197 ◽

1993 ◽

Vol 20 (2) ◽

pp. 197 ◽

Cited By ~ 63

Author(s):

JS Hawker ◽

CF Jenner

Keyword(s):

High Temperature ◽

Sucrose Synthase ◽

Starch Synthesis ◽

Dry Weight ◽

Grain Filling ◽

Soluble Starch ◽

Starch Synthase ◽

Adpglucose Pyrophosphorylase ◽

Udpglucose Pyrophosphorylase ◽

Lower Temperature

Ears of wheat were exposed for up to 10 days during the grain-filling stage to high temperature (35�C) and activities of five enzymes in the sucrose to starch pathway were compared to those in ears maintained at lower temperature (21�C day/16�C night). Two cultivars of wheat known to differ in their post-anthesis tolerance of high temperature were compared. On a per grain basis, the activity of sucrose synthase and of ADPglucose pyrophosphorylase in ears maintained at 21/16�C throughout did not change greatly between days 16 and 32 after anthesis, whereas UDPglucose pyrophosphorylase and soluble starch synthase activities declined with advancing development. Soluble starch synthase activity in grains of heated ears was decreased within 1 day to about one- half of the value in unheated grains, and 3 days' additional heating did not reduce the activity much further. Insoluble starch synthase activity was not significantly reduced by heating. Compared to soluble starch synthase, ADPglucose pyrophosphorylase activity was more slowly affected and decreased to a lesser extent by heat. Sucrose synthase and UDPglucose pyrophosphorylase activities were either not affected or only slightly reduced; part of this reduction could be due to advanced development at the higher temperature. In recovery experiments ears were heated for brief periods and then returned to 21/16�C for a few days. ADPglucose pyrophosphorylase and soluble starch synthase activities recovered in the cooler conditions but the other two enzymes generally only maintained or lost further activity. From a comparison of the activities of these enzymes with the rate of starch deposition, and by taking into account the effects of heating, it is proposed that the influence of heating on final grain dry weight is attributable to the observed reductions of soluble starch synthase activity.

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Leaf Color Retention, Dark Respiration, and Growth of Red-leafed Japanese Maples Under High Night Temperatures

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.115.1.135 ◽

1990 ◽

Vol 115 (1) ◽

pp. 135-140 ◽

Cited By ~ 6

Author(s):

D.L. Deal ◽

J.C. Raulston ◽

L.E. Hinesley

Keyword(s):

Plant Growth ◽

Dark Respiration ◽

Dry Weight ◽

Climatic Conditions ◽

Leaf Color ◽

Respiration Rates ◽

Color Retention ◽

Total Plant ◽

Early Fall ◽

Leaf Dry Weight

Red- and purple-leafed seedlings and clonal material selected for superior color and growth under northern climatic conditions may exhibit progressive color loss and reduced growth rates when exposed to the hot summers and high night temperatures of more southern climates. Studies were conducted to characterize the color loss associated with red-leafed seedlings of Acer palmatum Thunb. (Japanese maple), and to determine to what extent night temperatures affect the dark respiration, growth, and anthocyanin expression of A. palmatum `Bloodgood'. The percentage of seedlings within each of five color classes was determined for five dates from spring to early fall. Significant shifts in class distribution occurred on every evaluation date tested. The class changes contributing the most to these shifts varied with age of leaf material and date. Dark respiration rates increased by 0.09 mg CO2/g leaf dry weight per hour for every 1C rise in temperature, regardless of exposure duration. Dark respiration rates of 0.69 and 1.73 mg CO2/g per hour were found at 14 and 26C, respectively. The greatest amount of growth occurred during weeks 6 through 8 at a night temperature of 14C. Plant growth during this period increased by an average 51%, compared to that at warmer night temperatures. Ultimately, total plant growth at 14C decreased 7%, 19%, and 32% as night temperatures increased from 18 to 22 to 26C. Leaf redness index values at 14 or 18C were from two to seven times greater than those at warmer night temperatures.

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Phosphorus Rate, Leaching Fraction, and Substrate Influence on Influent Quantity, Effluent Nutrient Content, and Response of a Containerized Woody Ornamental Crop

HortScience ◽

10.21273/hortsci.43.3.906 ◽

2008 ◽

Vol 43 (3) ◽

pp. 906-912 ◽

Cited By ~ 19

Author(s):

James S. Owen ◽

Stuart L. Warren ◽

Ted E. Bilderback ◽

Joseph P. Albano

Keyword(s):

Plant Growth ◽

Phosphorus Uptake ◽

Dry Weight ◽

Nutrient Content ◽

Application Rate ◽

Pine Bark ◽

Mineral Aggregate ◽

P Rate ◽

Total Plant ◽

Leaching Fraction

Production of containerized nursery crops requires high inputs of water and mineral nutrients to maximize plant growth to produce a salable plant quickly. However, input efficiencies remain below 50% resulting in major quantities of water and nutrients leached. This study was conducted to determine if production factors could be altered to increase water and phosphorus uptake efficiency (PUE) without sacrificing plant growth. The effects of a pine bark substrate amendment (clay or sand) and a 50% reduction in both P application rate (1.0 g or 0.5 g) and leaching fraction (LF = effluent ÷ influent) (0.1 or 0.2) were investigated. Containerized Skogholm cotoneaster (Cotoneaster dammeri Schnied. ‘Skogholm’) was grown on gravel floor effluent collection plots that allowed for calculation of water and nutrient budgets. Pine bark amended with 11% (by vol.) Georgiana 0.25 to 0.85 mm calcined palygorksite-bentonite mineral aggregate (clay) increased available water 4% when compared with pine bark amended with 11% (by volume) coarse sand. Decreasing LF from 0.2 to 0.1 reduced cumulative container influent 25% and effluent volume 64%, whereas total plant dry weight was unaffected by LF. Reduction of target LF from 0.2 to 0.1 reduced dissolved reactive P concentration and content by 8% and 64%, respectively. In a sand-amended substrate, total plant dry weight decreased 16% when 1.0× P rate was reduced to 0.5× P, whereas total plant dry weight was unaffected by rate of P when pine bark was amended with clay. Plant content of all macronutrients, with the exception of N, increased when pine bark was amended with clay versus sand. Reducing P rate from 1.0× to 0.5× increased PUE 54% or 11% in a clay or sand-amended substrate, respectively. Amending pine bark with 11% (by volume) 0.25 to 0.85 mm calcined palygorksite-bentonite mineral aggregate produced an equivalent plant with half the P inputs and a 0.1 LF, which reduced water use 25% and P effluent losses 42% when compared with an industry representative substrate [8 pine bark : 1 sand (11% by volume)].

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