THE EFFECT OF SUPPLEMENTAL LIGHTING ON WINTER FLOWERING OF TRANSPLANTED Gypsophila paniculata

1986 ◽  
Vol 66 (3) ◽  
pp. 653-658 ◽  
Author(s):  
P. R. HICKLENTON
Keyword(s):  
High Pressure ◽  
Vegetative Growth ◽  
Photon Flux ◽  
Photosynthetic Photon Flux ◽  
Night Time ◽  
Low Level ◽  
Long Day ◽  
Gypsophila Paniculata ◽  
Production Strategies ◽  
Supplemental Lighting

Flowering of Gypsophila paniculata L. ’Bristol Fairy’ was promoted by supplemental lighting during the period September to February (fall) and January to June (spring) in greenhouses at latitude 45°N. Plants which received 42 or 63 d of night-time supplemental photosynthetic photon flux (PPF: 2000–0700 h; 93 μmol s−1 m−2 from high pressure sodium lamps) prior to transplanting flowered earlier and showed more vigorous vegetative growth than those subjected to only 21 d of supplemental PPF. Flowering did not occur in the fall crop for plants which received only low-level photoperiod extension lighting (8 μmol s−1 m−2, 2000–0700 h). Flowering in this cultivar is closely related to PPF during production as well as to photoperiod. Production strategies for northern greenhouses involving supplemental lighting treatments to plants prior to transplanting are suggested by these results.Key words: Gypsophila paniculata, supplemental lighting, flowering, long-day plant

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 Intermittent Light from a Rotating High-pressure Sodium Lamp Promotes Flowering of Long-day Plants

HortScience ◽  
2010 ◽  
Vol 45 (2) ◽  
pp. 236-241 ◽  
Author(s):  
Matthew G. Blanchard ◽  
Erik S. Runkle
Keyword(s):  
High Pressure ◽  
Photon Flux ◽  
Photosynthetic Photon Flux ◽  
Flower Number ◽  
Flower Bud ◽  
Intermittent Light ◽  
Rudbeckia Hirta ◽  
Long Day ◽  
Sodium Lamp ◽  
High Pressure Sodium Lamp

A technology for long-day (LD) lighting was evaluated for commercial production of ornamentals using a stationary high-pressure sodium (HPS) lamp with an oscillating aluminum parabolic reflector (rotating HPS lamp). We performed an experiment with four LD species (Campanula carpatica Jacq., Coreopsis grandiflora Hogg ex Sweet, Petunia ×hybrida Vilm.-Andr., and Rudbeckia hirta L.) to compare the efficacy of a rotating HPS lamp in promoting flowering with night-interruption (NI) lighting using incandescent (INC) lamps. Seedlings were grown under natural short-day (SD) photoperiods (12 h or less) and NI treatments were delivered from a 600-W rotating HPS lamp mounted at one gable end of the greenhouse or from INC lamps that were illuminated continuously for 4 h or cyclically for 6 min every 30 min for 4 h. Plants were grown at lateral distances of 1, 4, 7, 10, or 13 m from the rotating HPS lamp, which provided a maximum photosynthetic photon flux of 25.4 μmol·m−2·s−1 (at 1 m) to 0.3 μmol·m−2·s−1 (at 13 m). Control plants were grown under an uninterrupted 15-h skotoperiod. Within 16 weeks, 80% or greater of the plants within each species that received NI lighting had a macroscopic visible flower bud or inflorescence, whereas all species but Petunia ×hybrida remained vegetative under the SD. Flowering of all species grown at 13 m from the rotating HPS lamp was delayed by 14 to 31 d compared with those under continuous INC. The weekly operational costs to provide NI lighting to a 139-m2 greenhouse with one 600-W rotating HPS lamp or a standard cyclic INC lamp installation was estimated to be 80% to 83% lower compared with INC lighting for the entire 4-h NI. These results indicate that a rotating HPS lamp can be used to efficiently deliver LD lighting, but flowering time was delayed and flower number reduced in some species when the maximum NI light intensity was less than 2.4 μmol·m−2·s−1.

scholarly journals Night Temperature, Photosynthetic Photon Flux, and Long Days Affect Gypsophila paniculata Flowering

HortScience ◽  
1993 ◽  
Vol 28 (9) ◽  
pp. 888-890 ◽  
Author(s):  
Peter R. Hicklenton ◽  
Suzie M. Newman ◽  
Lindsay J. Davies
Keyword(s):  
Stem Elongation ◽  
Photon Flux ◽  
Fresh Weight ◽  
Photosynthetic Photon Flux ◽  
Night Temperature ◽  
Flower Yield ◽  
Long Day ◽  
Gypsophila Paniculata ◽  
Controlled Environments ◽  
The Times

The effects of night temperature (NT) and photosynthetic photon flux (PPF) on time to flower and flower yield in `Bristol Fairy' and `Bridal Veil' Gypsophila paniculata L. (perennial baby's breath) were studied in controlled environments. Plants were grown with nights at 8, 12, 16, and 20C and 450 or 710 μmol·s-1·m-2 photosynthetic photon flux (PPF). Days were at 20C. In both cultivars, the times from the start of treatments to visible bud and from visible bud to anthesis were delayed at the lower PPF and at an NT <20C. The delays in `Bristol Fairy' were greater than those in `Bridal Veil'. Failure of `Bristol Fairy' plants to reach anthesis was common at SC NT and either 450 or 710 μmol·s-1·m-2 PPF; whereas in `Bridal Veil', nearly all plants flowered, regardless of environmental conditions. Flower yield (measured as fresh weight of inflorescences) decreased with NT in `Bristol Fairy' but was highest at 8 or 12C in `Bridal Veil'. In a second experiment using the same cultivars, the effect of curtailing long-day (LD) conditions at various stages on stem elongation and flower yield was investigated. `Bristol Fairy' required more LD cycles (>56) than `Bridal Veil' for maximum stem elongation and flower yield. Terminating LD conditions before the start of inflorescence expansion resulted in lower yields and shorter plants in both cultivars.

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 High Pressure Sodium Irradiation and Infrared Radiation Accelerate Petunia Seedling Growth

1991 ◽  
Vol 116 (3) ◽  
pp. 435-438 ◽  
Author(s):  
David F. Graper ◽  
Will Healy
Keyword(s):  
High Pressure ◽  
Seedling Growth ◽  
Root Zone ◽  
Photon Flux ◽  
Growth Responses ◽  
Ambient Conditions ◽  
Fresh Weight ◽  
Photosynthetic Photon Flux ◽  
Ir Radiation ◽  
Relative Growth

The increase in photosynthetic photon flux (PPF) and plant temperature associated with supplemental high pressure sodium (HPS) irradiation were investigated during Petunia × hybrids Villm. `Red Flash' seedling development. Seedlings were treated for 14 days following emergence or 5 days after the first true leaf had expanded to 1 mm. Treatments consisted of continuous infrared (IR) radiation (Ambient + IR), ambient conditions with spill-over radiation from adjacent treatments (Ambient - IR), root zone heating to 19.5C (RZ Heat), continuous HPS irradiation at 167 μmol·s-1.m-2 PPF (HPS + IR) or continuous HPS irradiation at 167 μmol-1·m-2 PPF filtered through a water bath to remove IR (HPS - IR). Linear regression of natural log-transformed fresh weights indicated that increasing ambient PPF 53% and elevating plant temperature 4.3C (HPS + IR) increased seedling relative growth rate (RGR) by 45% compared with the control (Ambient - IR). Elevating plant temperature with + IR by 4.8C without supplementing PPF (Ambient + IR) increased RGR by 31% but failed to increase fresh weight (FW) above controls and resulted in etiolated plants that were unsuitable for transplanting. Once plants were removed from supplemental treatment and returned to ambient conditions, RGR for all treatments was similar. The increased FW promoted by IR and HPS treatments was maintained for up to 7 days after treatment. Therefore, the increased seedling growth responses observed with HPS treatment were due primarily to an increase in RGR during HPS treatment that is not sustained beyond treatment.

scholarly journals Effect of Photosynthetic Photon Flux and Temperature on Floral Evocation and Development in the Vernalization-sensitive Ornamental Perennial Salvia ×superba `Blaukönigin'

2006 ◽  
Vol 131 (4) ◽  
pp. 437-444 ◽  
Author(s):  
Grete Waaseth ◽  
Roar Moe ◽  
Royal D. Heins ◽  
Svein O. Grimstad
Keyword(s):  
Day Treatment ◽  
Leaf Number ◽  
Photon Flux ◽  
Photosynthetic Photon Flux ◽  
Flower Bud ◽  
Vegetative Development ◽  
Long Day ◽  
Floral Primordia ◽  
Subsequent Flowering ◽  
Floral Evocation

Varying photothermal ratios (PTR) were supplied to Salvia ×superba Stapf `Blaukönigin' during pre-inductive vegetative development with the exception of a short germination period under uniform conditions. In addition, both unvernalized plants and plants receiving a saturating vernalization treatment of 6 weeks at 5 °C were given two photosynthetic photon flux (PPF) levels (50 or 200 μmol·m-2·s-1) during subsequent inductive 16-hour long days. There were no effects of PTR treatments during vegetative development on subsequent flowering. However, the higher PPF level during inductive long days significantly accelerated floral evocation in unvernalized plants, lowering the leaf number at flowering. The effect was practically negligent after the vernalization requirement was saturated. In a second experiment, varying periods (4, 7, 10, and 14 days or until anthesis) at a PPF of 200 μmol·m-2·s-1 during 20-hour days were given at the beginning of a long-day treatment, either with or without preceding vernalization treatment. Flowering percentage increased considerably as the period at 200 μmol·m-2·s-1 was extended compared with plants grown at a lower PPF of 50 μmol·m-2·s-1. However, the leaf number on flowering plants was not affected, except in unvernalized plants receiving the highest PPF continuously until anthesis, where leaf number was reduced by almost 50%. We propose that the PPF-dependent flowering is facilitated either by the rate of ongoing assimilation or rapid mobilization of stored carbohydrates at the time of evocation. Abortion of floral primordia under the lower PPF (50 μmol·m-2·s-1) irrespective of vernalization treatment indicates that the assimilate requirement for flower bud development is independent of the mechanism for floral evocation.

scholarly journals Increasing Levels of Supplemental Led Light Enhances the Rate Flower Development of Greenhouse-Grown Cut Gerbera but Does Not Affect Flower Size and Quality

2020 ◽  
Author(s):  
Dave Llewellyn ◽  
Katherine Schiestel ◽  
Youbin Zheng
Keyword(s):  
Flower Development ◽  
Vegetative Growth ◽  
Photon Flux ◽  
Led Light ◽  
Yield And Quality ◽  
Flower Yield ◽  
Linear Relationships ◽  
Content Index ◽  
Lighting Intensity ◽  
Supplemental Lighting

To investigate the influence of supplemental lighting intensity on the production of cut gerbera during Canada&rsquo;s supplemental lighting season (November to March), trials were carried out at a research greenhouse. Five supplemental LED light intensity (LI) treatments provided canopy-level photosynthetic photon flux densities (PPFD) ranging from 41 to 180 &micro;mol&middot;m-2&middot;s-1. With a 12-h photoperiod, the treatments provided 1.76 to 7.72 mol&middot;m-2&middot;d-1 of supplemental light. Two cultivars of cut gerbera (Gerbera jamesonii H. Bolus ex Hook.f) were used to evaluate vegetative growth and flower production. Plugs of &lsquo;Ultima&rsquo; were assessed for vegetative growth and rate of flower development. There were minor LI treatment effects on number of leaves and chlorophyll content index and flowers from plants under the highest vs. lowest LI matured 10% faster. Reproductively mature &lsquo;Panama&rsquo; plants were assessed for flower yield and quality. &lsquo;Panama&rsquo; flowers from the highest LI treatment had shorter stems than the three lowest LI treatments, flowers from the middle LI treatment had larger diameter than the other treatments. Flowers from the lowest LI treatment had lower fresh mass than the three highest LI treatments. There were linear relationships between LI and numbers of flowers harvested, with the highest LI treatment producing 10.3 and 7.0 more total and marketable flowers per plant than the lowest LI treatment. In general, increasing levels of supplemental light had only minor effects on vegetative growth (young plants) and size and quality of harvested flowers (mature plants) but flowers from plants grown under higher LIs were more numerous and matured faster.

scholarly journals Optimization of Photosynthetic Photon Flux Density and Light Quality for Increasing Radiation-Use Efficiency in Dwarf Tomato under LED Light at the Vegetative Growth Stage

Plants ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 121
Author(s):  
Xinglin Ke ◽  
Hideo Yoshida ◽  
Shoko Hikosaka ◽  
Eiji Goto
Keyword(s):  
Vegetative Growth ◽  
Growth Stage ◽  
Light Quality ◽  
Dry Mass ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Photosynthetic Photon Flux ◽  
Use Efficiency ◽  
Radiation Use

Dwarf tomatoes are advantageous when cultivated in a plant factory with artificial light because they can grow well in a small volume. However, few studies have been reported on cultivation in a controlled environment for improving productivity. We performed two experiments to investigate the effects of photosynthetic photon flux density (PPFD; 300, 500, and 700 μmol m−2 s−1) with white light and light quality (white, R3B1 (red:blue = 3:1), and R9B1) with a PPFD of 300 μmol m−2 s−1 on plant growth and radiation-use efficiency (RUE) of a dwarf tomato cultivar (‘Micro-Tom’) at the vegetative growth stage. The results clearly demonstrated that higher PPFD leads to higher dry mass and lower specific leaf area, but it does not affect the stem length. Furthermore, high PPFD increased the photosynthetic rate (Pn) of individual leaves but decreased RUE. A higher blue light proportion inhibited dry mass production with the same intercepted light because the leaves under high blue light proportion had low Pn and photosynthetic light-use efficiency. In conclusion, 300 μmol m−2 s−1 PPFD and R9B1 are the recommended proper PPFD and light quality, respectively, for ‘Micro-Tom’ cultivation at the vegetative growth stage to increase the RUE.

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