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 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 Inhibition by NaCl of Net CO2 Fixation and Yield of Cucumber

1990 ◽  
Vol 115 (3) ◽  
pp. 472-477 ◽  
Author(s):  
Malcolm C. Drew ◽  
Pamela S. Hold ◽  
Geno A. Picchioni
Keyword(s):  
Co2 Fixation ◽  
Plant Performance ◽  
Sand Culture ◽  
Photon Flux ◽  
Detectable Effect ◽  
Fresh Weight ◽  
Photosynthetic Photon Flux ◽  
The Individual ◽  
The Relationship ◽  
Infrared Gas Analyzer

Cucumber (Cucumis sativus L. cv. Fidelio) grown in sand culture in the greenhouse was trickle-irrigated with nutrient solution containing 0, 10, or 50 mm NaCl. Gas exchange of Individual leaves was measured by a portable infrared gas analyzer et saturating photosynthetic photon flux. Salt at 10 mm had no detectable effect on plant performance, but exposure to 50 mm NaCl caused net CO2 fixation to decline by 33% and 48% in the eighth and ninth oldest leaves, respectively. Stomatal conductance and transpiration rate were also reduced (≈ 50%) In these leaves. These differences, as well as lower leaf water potentials, were associated with a 60% reduction in fruit fresh weight. The relationship between net CO2 fixation and intercellular (substomatal) CO2 concentrations was determined for individual, attached leaves of plants with roots exposed to various concentrations of NaCl in hydroponics. With 50 and 100 mm NaCl, a nonstomatal contribution to the inhibition of photosynthesis at the chloroplast level was Indicated by strong inhibition of CO, fixation at a saturating CO2 concentration. Salt-induced inhibition of CO2 fixation was associated with accumulation of Na+ and Cl-, and lower K+ in the individual leaves examined.

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 Radiation Intensity and Quality Affect Indoor Acclimation of Blueberry Transplants

HortScience ◽  
2021 ◽  
pp. 1-10
Author(s):  
Celina Gómez ◽  
Megha Poudel ◽  
Matias Yegros ◽  
Paul R. Fisher
Keyword(s):  
Root Biomass ◽  
Dry Mass ◽  
Vaccinium Corymbosum ◽  
Photon Flux ◽  
Growth Responses ◽  
Photosynthetic Photon Flux ◽  
Light Emitting ◽  
Spectral Changes ◽  
Changes Over Time ◽  
Over Time

The objectives were to characterize and compare shrinkage (i.e., transplant loss) and growth of tissue-cultured blueberry (Vaccinium corymbosum) transplants acclimated in greenhouses or indoors under 1) different photosynthetic photon flux densities (PPFDs) (Expt. 1); or 2) spectral changes over time using broad-spectrum white (W; 400 to 700 nm) light-emitting diodes (LEDs) without or with red or far-red (FR) radiation (Expt. 2). In Expt. 1, ‘Emerald’ and ‘Snowchaser’ transplants were acclimated for 8 weeks under PPFDs of 35, 70, 105, or 140 ± 5 µmol·m‒2·s‒1 provided by W LED fixtures for 20 h·d−1. In another treatment, PPFD was increased over time by moving transplants from treatment compartments providing 70 to 140 µmol·m‒2·s‒1 at the end of week 4. Transplants were also acclimated in either a research or a commercial greenhouse (RGH or CGH, respectively). Shrinkage was unaffected by PPFD, but all transplants acclimated indoors had lower shrinkage (≤4%) than those in the greenhouse (15% and 17% in RGH and CGH, respectively), and generally produced more shoot and root biomass, regardless of PPFD. Growth responses to increasing PPFD were linear in most cases, although treatment effects after finishing were generally not significant among PPFD treatments. In Expt. 2, ‘Emerald’ transplants were acclimated for 8 weeks under constant W, W + red (WR), or W + FR (WFR) radiation, all of which provided a PPFD of 70 ± 2 μmol·m−2·s−1 for 20 h·d−1. At the end of week 4, a group of transplants from WR and WFR were moved to treatment compartments with W (WRW or WFRW, respectively) or from W to a research greenhouse (WGH), where another group of transplants were also acclimated for 8 weeks (GH). Shrinkage of transplants acclimated indoors was also low in Expt. 2, ranging from 1% to 4%. In contrast, shrinkage of transplants acclimated in GH or under WGH was 37% or 14%, respectively. Growth of indoor-acclimated transplants was generally greater than that in GH or under WGH. Although growth responses were generally similar indoors, plants acclimated under WFR had a higher root dry mass (DM) and longer roots compared with GH and WGH.

scholarly journals Plant Factories Are Heating Up: Hunting for the Best Combination of Light Intensity, Air Temperature and Root-Zone Temperature in Lettuce Production

2021 ◽  
Vol 11 ◽  
Author(s):  
Laura Carotti ◽  
Luuk Graamans ◽  
Federico Puksic ◽  
Michele Butturini ◽  
Esther Meinen ◽  
...  
Keyword(s):  
Light Intensity ◽  
Air Temperature ◽  
Dry Matter ◽  
Root Zone ◽  
Incident Light ◽  
Photon Flux ◽  
Dry Matter Content ◽  
Fresh Weight ◽  
Root Zone Temperature ◽  
Zone Temperature

This study analyzed interactions among photon flux density (PPFD), air temperature, root-zone temperature for growth of lettuce with non-limiting water, nutrient, and CO2 concentration. We measured growth parameters in 48 combinations of a PPFD of 200, 400, and 750 μmol m–2 s–1 (16 h daylength), with air and root-zone temperatures of 20, 24, 28, and 32°C. Lettuce (Lactuca sativa cv. Batavia Othilie) was grown for four cycles (29 days after transplanting). Eight combinations with low root-zone (20 and 24°C), high air temperature (28 and 32°C) and high PPFD (400 and 750 μmol m–2 s–1) resulted in an excessive incidence of tip-burn and were not included in further analysis. Dry mass increased with increasing photon flux to a PPFD of 750 μmol m–2 s–1. The photon conversion efficiency (both dry and fresh weight) decreased with increasing photon flux: 29, 27, and 21 g FW shoot and 1.01, 0.87, and 0.76 g DW shoot per mol incident light at 200, 400, and 750 μmol m–2 s–1, respectively, averaged over all temperature combinations, following a concurrent decrease in specific leaf area (SLA). The highest efficiency was achieved at 200 μmol m–2 s–1, 24°C air temperature and 28°C root-zone temperature: 44 g FW and 1.23 g DW per mol incident light. The effect of air temperature on fresh yield was linked to all leaf expansion processes. SLA, shoot mass allocation and water content of leaves showed the same trend for air temperature with a maximum around 24°C. The effect of root temperature was less prominent with an optimum around 28°C in nearly all conditions. With this combination of temperatures, market size (fresh weight shoot = 250 g) was achieved in 26, 20, and 18 days, at 200, 400, and 750 μmol m–2 s–1, respectively, with a corresponding shoot dry matter content of 2.6, 3.8, and 4.2%. In conclusion, three factors determine the “optimal” PPFD: capital and operational costs of light intensity vs the value of reducing cropping time, and the market value of higher dry matter contents.

scholarly journals Supplemental Light Quality Affects Budbreak, Yield, and Vase Life of Cut Roses

HortScience ◽  
1993 ◽  
Vol 28 (6) ◽  
pp. 621-622 ◽  
Author(s):  
G.L. Roberts ◽  
M.J. Tsujita ◽  
B. Dansereau
Keyword(s):  
High Pressure ◽  
Total Energy ◽  
Quality Index ◽  
Light Quality ◽  
Metal Halide ◽  
Photon Flux ◽  
Vase Life ◽  
Photosynthetic Photon Flux ◽  
R:Fr Ratio ◽  
Metal Halide Lamps

Rosa ×hybrida `Samantha' plants were grown under high-pressure sodium (HPS) lamps, HPS lamps fitted with blue gel filters to reduce the red to far-red (R:FR) ratio, or metal halide lamps. R: FR ratios were 1:0.95, 1:2, and 1:0.26 for HPS; filtered HPS, and metal halide, respectively. Although the R: FR ratio for metal halide was 3.5 times higher than for HPS, the total energy from 630 to 750 nm was 2.8 times lower. At a nighttime supplemental photosynthetic photon flux of 70 to 75 μmol·m-2.s-1, plants under HPS and metal halide lamps produced 49 % and 64% more flowering shoots, respectively, than those under filtered HPS (averaged over two crop cycles). The quality index for flowers under HPS, metal halide, and filtered HPS was 25.0, 23.3, and 18.5, respectively. Vase life was 10 to 11 days, regardless of treatment.

scholarly journals Branching of Chrysanthemum Cultivars Varies with Season, Temperature, and Photosynthetic Photon Flux

HortScience ◽  
1996 ◽  
Vol 31 (1) ◽  
pp. 74-78 ◽  
Author(s):  
Richard K. Schoellhorn ◽  
James E. Barrett ◽  
Terril A. Nell
Keyword(s):  
Linear Relationship ◽  
Air Temperature ◽  
Environmental Conditions ◽  
Root Zone ◽  
Lateral Branch ◽  
Photon Flux ◽  
Photosynthetic Photon Flux ◽  
Lateral Shoot ◽  
Commercial Cultivars ◽  
Lateral Branches

Effects of photosynthetic photon flux (PPF) and temperature on quantitative axillary budbreak and elongation of pinched chrysanthemum [Dendranthema ×grandiflorum (Ramat.) Kitamura] plants were studied in three experiments. In Expt. 1, 12 commercial cultivars were compared under fall and spring environmental conditions. Spring increases in lateral shoot counts were attributable to increased PPF and air temperature. Cultivars varied from 0 to 12 lateral branches per pinched plant and by as much as 60% between seasons. There was a linear relationship between lateral branches >5 cm at 3 weeks after pinching and final branch count (y = 0.407 + 0.914(x), r2 = 0.92). In Expt. 2, air was at 20 or 25C and the root zone was maintained at 5, 0, or –5C relative to air temperature. With air at 20C, lateral branch counts (3 weeks after pinch) declined by ≤50% with the medium at 15C relative to 25C. At 25C, lateral branch count was lower with medium at 30C than at 20C. Cultivars differed in their response to the treatments. Experiment 3 compared the interactions among temperature, PPF, and cultivar on lateral branch count. Depending on cultivar, the count increased the higher the PPF between 400 and 1400 μmol·m–2·s–1. Air temperature had no effect on lateral branch count. PPF had a stronger effect on lateral branch count than air temperature, and cultivars differed in their response.

SUPPLEMENTARY LIGHTING FOR RESEARCH GREENHOUSES

1984 ◽  
Vol 64 (3) ◽  
pp. 773-779 ◽  
Author(s):  
E. ANN CLARK ◽  
M. D. DEVINE
Keyword(s):  
High Pressure ◽  
Plant Growth ◽  
Flux Density ◽  
Growth And Development ◽  
Photosynthetic Photon Flux Density ◽  
Metal Halide ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Photosynthetic Photon Flux ◽  
Supplementary Lighting

The growth and development of six plant species were measured under a standardized photosynthetic photon flux density (PPFD) supplied by fluorescent, metal halide, or high-pressure sodium lamps. Overall, plant growth and seed yield were in the order of high-pressure sodium > metal halide > fluorescent. Although the units tested were unable to supply a uniform, high flux density, acceptable plant growth was achieved under the compromise arrangements used.Key words: Fluorescent, metal halide, high pressure sodium, supplementary lighting

scholarly journals Irradiance Levels Affect in vitro and Greenhouse Growth, Flowering, and Photosynthetic Behavior of A Hybrid Phalaenopsis Orchid

2001 ◽  
Vol 126 (5) ◽  
pp. 531-536 ◽  
Author(s):  
Elise A. Konow ◽  
Yin-Tung Wang
Keyword(s):  
Malic Acid ◽  
Agar Medium ◽  
Photon Flux ◽  
Fresh Weight ◽  
Photosynthetic Photon Flux ◽  
Greenhouse Production ◽  
Full Sunlight ◽  
Fluorescent Lamps ◽  
Sucrose Level

Presently, there are no standards for producing Phalaenopsis Blume (the moth orchids) as a flowering, potted crop. Determining optimal irradiance for in vitro and greenhouse production will help optimize growth and flowering. Four-month-old, aseptically propagated Phalaenopsis Atien Kaala seedlings with 1.0 cm leaf spread were transferred to a sterile agar medium in November 1995. They were placed under 10, 20, 40, or 80 μmol·m-2·s-1 photosynthetic photon flux (PPF) from cool-white fluorescent lamps. In June 1996, plants grown under 40 or 80 μmol·m-2·s-1 in vitro PPF had 38% greater fresh weight (FW), wider leaves, and more roots than those under the two lower PPF levels. Plants from each in vitro PPF were then transplanted and grown ex vitro in a greenhouse (GH) under high, medium, or low PPF, representing 12.0%, 5.4%, or 2.6% of full sunlight, respectively. Full sunlight at this location was 2300 and 1700 μmol·m-2·s-1 in August 1996 and January 1997, respectively. In November 1996 and June 1997, plants that had received 40 μmol·m-2·s-1 in vitro PPF and then grown under the high or medium GH PPF had the greatest FWs. Overall, plants under the high, medium, or low GH PPF had average FWs of 61, 36, or 17 g, respectively, in June 1997. By mid-September 1997, plants had increasingly larger leaves and higher concentrations of malic acid, sucrose, and starch as GH PPF increased. Leaf glucose and fructose concentrations remained constant as GH PPF increased; however, sucrose level doubled and malic acid concentration increased by nearly 50% from the low to high GH PPF. Each doubling in GH PPF more than doubled plant FW. Plants grown under the high, medium, or low GH PPF had 98%, 77%, or 2% flowering, respectively, in Spring 1998. Anthesis occurred 2 weeks earlier under the high GH PPF. Plants grown under the high GH PPF had twice as many flowers and larger flowers than those grown under the medium PPF.

scholarly journals Comparison of Supplemental Lighting Provided by High-pressure Sodium Lamps or Light-emitting Diodes for the Propagation and Finishing of Bedding Plants in a Commercial Greenhouse

HortScience ◽  
2019 ◽  
Vol 54 (1) ◽  
pp. 52-59
Author(s):  
Joshua K. Craver ◽  
Jennifer K. Boldt ◽  
Roberto G. Lopez
Keyword(s):  
High Pressure ◽  
Pennisetum Glaucum ◽  
Plant Quality ◽  
Plant Production ◽  
Photon Flux ◽  
Nutrient Concentrations ◽  
Ambient Conditions ◽  
Light Emitting ◽  
Bedding Plant ◽  
Supplemental Lighting

High-quality young plant production in northern latitudes requires supplemental lighting (SL) to achieve a recommended daily light integral (DLI) of 10 to 12 mol·m−2·d−1. High-pressure sodium (HPS) lamps have been the industry standard for providing SL in greenhouses. However, high-intensity light-emitting diode (LED) fixtures providing blue, white, red, and/or far-red radiation have recently emerged as a possible alternative to HPS lamps for greenhouse SL. Therefore, the objectives of this study were to 1) quantify the morphology and nutrient concentration of common and specialty bedding plant seedlings grown under no SL, or SL from HPS lamps or LED fixtures; and 2) determine whether SL source during propagation or finishing influences finished plant quality or flowering. The experiment was conducted at a commercial greenhouse in West Lafayette, IN. Seeds of New Guinea impatiens (Impatiens hawkeri ‘Divine Blue Pearl’), French marigold (Tagetes patula ‘Bonanza Deep Orange’), gerbera (Gerbera jamesonii ‘Terracotta’), petunia (Petunia ×hybrida ‘Single Dreams White’), ornamental millet (Pennisetum glaucum ‘Jester’), pepper (Capsicum annuum ‘Hot Long Red Thin Cayenne’), and zinnia (Zinnia elegans ‘Zahara Fire’) were sown in 128-cell trays. On germination, trays were placed in a double-poly greenhouse under a 16-hour photoperiod of ambient solar radiation and photoperiodic lighting from compact fluorescent lamps providing a photosynthetic photon flux density (PPFD) of 2 µmol·m−2·s−1 (ambient conditions) or SL from either HPS lamps or LED fixtures providing a PPFD of 70 µmol·m−2·s−1. After propagation, seedlings were transplanted and finished under SL provided by the same HPS lamps or LED fixtures in a separate greenhouse environment. Overall, seedlings produced under SL were of greater quality [larger stem caliper, increased number of nodes, lower leaf area ratio (LAR), and greater dry mass accumulation] than those produced under no SL. However, seedlings produced under HPS or LED SL were comparable in quality. Although nutrient concentrations were greatest under ambient conditions, select macro- and micronutrient concentrations also were greater under HPS compared with LED SL. SL source during propagation and finishing had little effect on flowering and finished plant quality. Although these results indicate little difference in plant quality based on SL source, they further confirm the benefits gained from using SL for bedding plant production. In addition, with both SL sources producing a similar finished product, growers can prioritize other factors related to SL installations such as energy savings, fixture price, and fixture lifespan.

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