High R/FR HPS-pulses enhance earliness of flowering of exacum (Exacum affine Balf. F.) and geranium (Pelargonium × hortorum L. H. Bailey)

1993 ◽  
Vol 73 (4) ◽  
pp. 1163-1167 ◽  
Author(s):  
Michel Tardif ◽  
Blanche Dansereau
Keyword(s):  
High Pressure ◽  
Key Words ◽  
Growth Index ◽  
Dry Weight ◽  
Light Treatment ◽  
Photon Flux ◽  
Ambient Light ◽  
Photosynthetic Photon Flux ◽  
Top Dry Weight ◽  
Exacum Affine

Four consecutive crops (Fall 1988, Winter 1989, Summer 1989 and Fall 1989) of exacum (Exacum affine Balf. f. ’Elfin’) and geranium (Pelargonium × hortorum L. H. Bailey ’Hollywood Star’ and ’Hollywood Red’) were grown in a greenhouse under three lighting treatments: ambient: 16-h high pressure sodium (HPS) lighting of 100 μmol m−2 s−1 between 0600 and 2200 h; and 16 h HPS-pulse lighting (45 s shut off, 90 s recharge) once every hour between 0600 and 2200 h. The growth index [(height × width)/2] of exacum plants was similar, regardless of the light treatment used. However the growth index of both geranium cultivars receiving HPS-pulse lighting was significantly less than those receiving the two other treatments. Exacum top dry weight was 225% greater under pulse lighting than under ambient light. During fall 1988, HPS-pulse lighting increased flower dry weight of Hollywood Red by 400% and 87% compared to ambient and HPS lighting, respectively. Key words: Exacum affine, HPS-pulse, Pelargonium × hortorum, photomorphogenesis, photosynthesis, photosynthetic photon flux

UTILISATION D’UN MODULE ROTATIF À DEUX NIVEAUX ET DE L’ÉCLAIRAGE ARTIFICIEL POUR LA CULTURE DE L’EXACUM ET DU GÉRANIUM

1990 ◽  
Vol 70 (3) ◽  
pp. 915-923
Author(s):  
MICHEL TARDIF ◽  
BLANCHE DANSEREAU ◽  
ROGER THÉRIAULT
Keyword(s):  
Dry Weight ◽  
Photon Flux ◽  
Ambient Light ◽  
Level System ◽  
Photosynthetic Photon Flux ◽  
The Third ◽  
Width Effect ◽  
Production Practices ◽  
Exacum Affine ◽  
Standard Production

A cultivar of exacum (Exacum affine Balf. f. ’Elfin’) as well as two cultivars of geranium (Pelargonium × hortorum L. H. Bailey ’Hollywood Star’ and ’Hollywood Red’) were given three light treatments. The first treatment using standard production practices received only ambient light, the second treatment using standard production practices received ambient light combined with a photosynthetic photon flux (PPF) of 100 μmol m−2 s−1 provided by high pressure sodium (HPS) lamps, and the third treatment used a rotating two-level system where ambient light on the top level and a PPF of 100 μmol m−2 s−1 on the bottom level were used. An increased growth (height and width) effect was observed for the two geranium cultivars grown on the two-level system compared to the plants receiving the other treatments. The dry weight of exacums grown on the two-level system was 25% greater than those plants receiving only ambient light (during Winter/Spring-88). Certain processes such as thigmomorphogenesis, thermomorphogenesis, and photomorphogenesis may explain physiological modifications undergone by the plants growing on the two-level system.Key words: Rotating two-level system, photosynthetic photon flux, Exacum affine, Pelargonium × hortorum, photomorphogenesis, thermomorphogenesis

Incorporation de résidus organiques dans un substrat tourbeux pour la production d'impatiens et de géraniums

1998 ◽  
Vol 78 (1) ◽  
pp. 131-138
Author(s):  
Fabienne Gauthier ◽  
Serge Gagnon ◽  
Blanche Dansereau
Keyword(s):  
Key Words ◽  
Growth Parameters ◽  
Growth Index ◽  
Visual Quality ◽  
Dry Weight ◽  
Peat Moss ◽  
Paper Sludge ◽  
Organic Residues ◽  
Top Dry Weight ◽  
Impatiens Wallerana

During winter 1994 and spring-summer 1994, seedlings of Impatiens wallerana 'Accent Coral' and Pelargonium × hortorum 'Orbit Hot Pink' were grown in a commercial substrate (PRO-MIX 'BX') or in one of 24 substrates composed of perlite (35% by volume), peat moss and of six organic residues (composted water-treated sludge, forestry compost, fresh or composted used peat extracted by biofilter during treatment of municipal water, and fresh or composted paper sludge). The purpose of the study was to determine the maximal proportion of these residues to be incorporated into a peat substrate to obtain quality plants. Growth parameters (growth index, top dry weight, and visual quality) generally decreased with increasing proportion (5, 10, 25 or 40% per volume). During the winter experiment, growth of control plants was superior to growth of plants grown in substrates composed of residues. An incorporated proportion of 25% per volume was shown to be maximal for the production of impatiens and geraniums. Key words: Impatiens wallerana, Pelargonium × hortorum, water treated sludge, composted wastes, peat moss, subirrigation

scholarly journals Vegetative Growth of Potato under High-pressure Sodium, High-pressure Sodium SON-Agro, and Metal Halide Lamps

HortScience ◽  
1995 ◽  
Vol 30 (2) ◽  
pp. 374-376 ◽  
Author(s):  
N.C. Yorio ◽  
C.L. Mackowiak ◽  
R.M. Wheeler ◽  
J.C. Sager
Keyword(s):  
High Pressure ◽  
Vegetative Growth ◽  
Dry Weight ◽  
Metal Halide ◽  
Photon Flux ◽  
Spectral Quality ◽  
Photosynthetic Photon Flux ◽  
Total Dry Weight ◽  
Metal Halide Lamps

Potato (Solanum tuberosum L. cvs. Norland and Denali) plants were grown under high-pressure sodium (HPS), metal halide (MH), and blue-light-enhanced SON-Agro high-pressure sodium (HPS-S) lamps to study the effects of lamp spectral quality on vegetative growth. All plants were initiated from in vitro nodal cultures and grown hydroponically for 35 days at 300 μmol·m–2·s–1 photosynthetic photon flux (PPF) with a 12-hour light/12-hour dark photoperiod and matching 20C/16C thermoperiod. `Denali' main stems and internodes were significantly longer under HPS compared to MH, while under HPS-S, lengths were intermediate relative to those under other lamp types, but not significantly different. `Norland' plants showed no significant differences in stem and internode length among lamp types. Total dry weight of `Denali' plants was unaffected by lamp type, but `Norland' plants grown with HPS had significantly higher dry weight than those under either HPS-S or MH. Spectroradiometer measurements from the various lamps verified the manufacturer's claims of a 30% increase in ultraviolet-blue (350 to 450 nm) output from the HPS-S relative to standard HPS lamps. However, the data from `Denali' suggest that at 300 μmol·m–2·s–1 total PPF, the increased blue from HPS-S lamps is still insufficient to consistently maintain short stem growth typical of blue-rich irradiance environments.

scholarly journals Influence du mode d'utilisation de l'éclairage d'appoint sur la productivité et la physiologie de la tomate de serre

1991 ◽  
Vol 71 (3) ◽  
pp. 923-932 ◽  
Author(s):  
François Vézina ◽  
Marc J. Trudel ◽  
André Gosselin
Keyword(s):  
High Pressure ◽  
Lycopersicon Esculentum ◽  
Key Words ◽  
Photon Flux ◽  
Photosynthetic Photon Flux ◽  
Tomato Plants ◽  
Distribution Mode ◽  
Key Words Tomato ◽  
Supplemental Lighting ◽  
H 20

Tomato plants (Lycopersicon esculentum 'Vedettos') were submitted to 10 light treatments obtained by modifying the supplemental photosynthetic photon flux (FPP) (0, 100, 150 μmol m−2 s−1), the photoperiod (natural, 14 h, 17 h, 20 h, 24 h) and the light distribution mode (one or two dark periods). Supplemental light was supplied by high-pressure vapor sodium lamps (HPS). Our results showed that supplemental lighting at a level of 150 μmol m−2 s−1 (PAR) helped to maintain a weekly yield of over 1 kg m−2 during November, December and January. Prolongation of the photoperiod over 14 h did not increase the yield. Plants exposed to continuous lighting were damaged even if they had been previously exposed to long photoperiods (17 and 20 h). For photoperiods of 17 and 20 h, lighting during the night which generated two dark periods per day damaged the plants and reduced the yields. Key words: Tomato (Lycopersicon esculentum), greenhouse, supplemental lighting, continuous lighting, yield, physiological disorders

scholarly journals Growth of Two Subtropical Ornamentals Using Coir (Coconut Mesocarp Pith) as a Peat Substitute

HortScience ◽  
1994 ◽  
Vol 29 (12) ◽  
pp. 1484-1486 ◽  
Author(s):  
Alan W. Meerow
Keyword(s):  
Growth Index ◽  
Dry Weight ◽  
Water Holding Capacity ◽  
Sphagnum Peat ◽  
Coir Dust ◽  
Top Dry Weight ◽  
Water Holding ◽  
Ixora Coccinea ◽  
Coconut Mesocarp ◽  
Over Time

Growth of Pentas lanecolata (Forssk.) Deflers `Starburst Pink' and Ixora coccinea L. `Maui' was compared in container media using sphagnum peat, sedge peat, or coir dust as their peat components. Growth index and top and root dry weights of both crops were significantly better in coir-based medium than sedge peat-based medium. Pentas grew equally well in coir- and sphagnum peat-based medium. Growth index and top dry weight of Ixora were significantly lower in the coir-based than the sphagnum peat-based medium, although root dry weights were equal. This difference was not apparent and may have been caused by N drawdown in the coir-based mix. The sedge peat-based medium had the highest air porosity and the lowest water-holding capacity of the three media at the initiation of the trials, but at the termination of the study, it showed a reversal of these characteristics. The coir-based medium showed the least change in these attributes over time. Coir dust seems to be an acceptable substitute for sphagnum or sedge peat in soilless container media, although nutritional regimes may need to be adjusted on a crop-by-crop basis.

scholarly journals EFFECT OF LIGHT, CO2, AND SUCROSE CONCENTRATIONS ON THE IN VITRO GROWTH OF WHITE POTATO (SOLANUM TUBEROSUM L.)

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 696f-696
Author(s):  
N.C. Yorio ◽  
R.M. Wheeler ◽  
R.C. Weigel
Keyword(s):  
Solanum Tuberosum ◽  
Solanum Tuberosum L ◽  
Dry Weight ◽  
Growth Chamber ◽  
Photon Flux ◽  
Photosynthetic Photon Flux ◽  
White Potato ◽  
High Sucrose ◽  
Effect Of Light

Growth measurements of potato (Solanum tuberosum L.) cvs. Norland (NL), Denali (DN), and Kennebec (KN) were taken from 21-day-old plantlets grown in vitro. Studies were conducted in a growth chamber, with nodal explants grown in culture tubes with loose-fitted Magenta 2-way caps containing Murashige and Skoog salts with either 0, 1, 2 or 3% sucrose. The cultures received either 100 or 300 μmol m-2 s-1 photosynthetic photon flux (PPF), and the growth chamber was maintained at either 400 or 4000 μmol mol-1 CO2. All cvs. showed significant increases in growth on 0% sucrose media at 4000 μmol mol-1 CO2, indicating an autotrophic response. At 400 μmol mol-1 CO2, all cvs. showed an increase in total plantlet dry weight (DW) with increasing sucrose under both PPF levels. Within any sucrose treatment, the highest total DW for all cvs. resulted from 300 μmol m-2 s-1 PPF and 4000 μmol mol-1 CO2. At 4000 μmol mol-1 CO2, shoot DW declined with sucrose above 2% for DN and sucrose above 1% for NL at both PPF levels, suggesting that high sucrose levels may hinder growth when CO2 enrichment is used.

scholarly journals PHOTOAUTOTROPHIC MICROPROPAGATION OF CYMBIDIUM PLB

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 585c-585 ◽  
Author(s):  
Chieri Kubota ◽  
Chalermpol Kirdmanee ◽  
Toyoki Kozai
Keyword(s):  
Chlorophyll Content ◽  
Dry Weight ◽  
Co2 Concentration ◽  
Photon Flux ◽  
Ms Medium ◽  
Photosynthetic Photon Flux ◽  
Photoautotrophic Growth ◽  
Lighting Conditions ◽  
Photoautotrophic Micropropagation

Cymbidium (cv. Lisa rose) PLB (protocorm-like bodies) were cultured in liquid 1/2 MS medium with/without 20 mg g-1 sucrose under continuous lighting conditions. The vessels were shaken at 100 rpm under PPF (photosynthetic photon flux) of 20 and 140 μmol m-2 s-1 and CO2 concentrations outside the vessel (Cout) of 450 and 2000 μmol mol-1 conditions. Photoautotrophic growth was obtained at high PPF and high Cout. The chlorophyll content of the PLB in the medium without sucrose at high PPF and high Cout was almost 3 times that with sucrose at low PPF and low Cout. The number of newly developed PLB with sucrose at low PPF and low Cout was 1.6 times that without sucrose at high PPF and high Cout; the dry weight per unit PLB with sucrose at low PPF and low Cout was almost 3 times that without sucrose at high PPF and high Cout. Photoautotrophic growth of the PLB might be further promoted at higher CO2 concentration (> 1%).

scholarly journals Growth and Interior Performance of Poinsettia in Media Containing Composted Cotton Burrs

HortScience ◽  
1990 ◽  
Vol 25 (4) ◽  
pp. 407-408 ◽  
Author(s):  
Yin-Tung Wang ◽  
Thomas M. Blessington
Keyword(s):  
Electrical Conductance ◽  
Dry Weight ◽  
Pine Bark ◽  
Photon Flux ◽  
Growth Media ◽  
Euphorbia Pulcherrima ◽  
Photosynthetic Photon Flux ◽  
Rooted Cuttings ◽  
Sphagnum Peat ◽  
Number Of Branches

Rooted cuttings of Euphorbia pulcherrima Willd. ex Klotzsch cv. Gutbier V-14 Glory were planted in 2-liter containers with growth media having 0% to 75% composted cotton burrs (CCB) in combination with sphagnum peat and/or composted pine bark. Leachates from media with 50% or more CCB had higher initial electrical conductance (EC) (3.7 to 4.0 dS·m-l) than that from media with 25% or no CCB (2.8 to 3.0 dS·m-l) 2 weeks after planting. The differences in leachate EC declined after an additional 9 weeks. Media containing CCB produced slightly shorter and narrower plants with 10% smaller inflorescences and less dry weight than plants grown in a medium consisting of equal volumes of peatmoss and bark. Number of branches and bracts, days to bloom, and plant grade after 30 days under 15 μmol·s-l· m-2 photosynthetic photon flux were unaffected by media.

scholarly journals Modification of Petunia Seedling Carbohydrate Partitioning by Irradiance

1992 ◽  
Vol 117 (3) ◽  
pp. 477-480
Author(s):  
David F. Graper ◽  
Will Healy
Keyword(s):  
Petunia Hybrida ◽  
Soluble Sugars ◽  
Dry Weight ◽  
Invertase Activity ◽  
Acid Invertase ◽  
Starch Accumulation ◽  
Photon Flux ◽  
Photosynthetic Photon Flux ◽  
Total Carbohydrate ◽  
Relative Growth

Petunia × hybrida Villm. `Red Flash' plants received either 10 or 20 mol·day-1 photosynthetic photon flux (PPF) in growth chambers at: 175 μmol·m-2·s-1 for 16 hours, 350 μmol·m-2·s-1 for 8 or 16 hours, or 350 μmol·m-2 s-1 for 8 hours plus 8 hours of incandescent photoperiod extension (5 μmol·m-2·s-1 PPF). The irradiation components of peak, total, and duration were examined. Doubling total PPF increased total carbohydrate (CHO) production by 60%, seedling dry weight (DW) by 30%, rate of seedling growth by 25%, and acid invertase activity by 50% compared to the other treatments, once the seedlings had reached the two-leaf stage. Seedlings receiving 20 mol·day-1 PPF partitioned 14% more CHO into ethanol soluble sugars rather than starch, which may explain the increase in relative growth rate observed with supplemental irradiance treatments. Extending the photoperiod for 8 hours with 5 μmol·m-2·s-1 PPF reduced total CHO production by 50% compared to the same treatment without photoperiodic lighting. Treatment with 350 μmol·m-2·s-1 for 8 hours resulted in the highest O2 evolution (8.8 μmol O2/min per dm2). Increasing the photoperiod from 8 to 16 hours gave the lowest rate of O2 evolution (4.5 μmol O2/min per dm2). Previous reports of the importance of photosynthetic period in controlling partitioning between starch and sugars may have simply observed a decreasing rate of starch accumulation due to increased total PPF.

scholarly journals Night Interruption Lighting Is Beneficial in the Production of Plugs of Dahlia `Sunny Rose'

HortScience ◽  
2000 ◽  
Vol 35 (7) ◽  
pp. 1244-1246
Author(s):  
Garry Legnani ◽  
William B. Miller
Keyword(s):  
Shoot Growth ◽  
Physiological State ◽  
Dry Weight ◽  
Photon Flux ◽  
Photosynthetic Photon Flux ◽  
Fibrous Root ◽  
Shoot Dry Weight ◽  
Total Plant ◽  
Short Days ◽  
Foliar N Concentration

Experiments were conducted to evaluate effects of photoperiod on growth and dry-weight partitioning in Dahlia sp. `Sunny Rose' during both seedling (plug) production and subsequent production in 10-cm pots. Plugs were grown under short days [9-hour natural photosynthetic photon flux (PPF)] or long days (same 9-hour PPF plus a 4-hour night interruption with incandescent light). Total plant dry weight was unaffected by photoperiod; however, long days (LD) inhibited tuberous root development and increased shoot dry weight, fibrous root dry weight, leaf area, shoot length, and number of leaf pairs. Long days reduced plug production time by ≈1 week compared with short days (SD). Following transplanting to 10-cm pots, shoot growth and foliar development were superior under LD. There was no effect of photoperiod on foliar N concentration. The superior growth of LD plugs following transplanting can be attributed to the plant being in a physiological state conducive to shoot expansion instead of storage.

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