Weed Growth in Response to Greenhouse Supplemental Lighting

Weed Science ◽  
1975 ◽  
Vol 23 (4) ◽  
pp. 314-316 ◽  
Author(s):  
W. B. Duke ◽  
J. F. Hunt
Keyword(s):  
Light Intensity ◽  
Dry Weight ◽  
Metal Halide ◽  
Lighting System ◽  
Field Growth ◽  
Weed Growth ◽  
Supplemental Lighting ◽  
Lighting Systems ◽  
Growth Habits

Studies were conducted to compare weed growth under lighting systems composed of metal halide (MH) lamps and fluorescent-incandescent (FI) lamps. The MH lamps provided more light intensity and over a 6-week period caused plant dry weight to be 60 to 70% more than for plants exposed to the FI lamps. One week after emergence, all plants under the higher intensity MH lamps had larger stems and cotyledons or first true leaves. Six weeks after planting, weeds grown under the MH lamps had larger leaves, shorter internodes, thicker stems, and, in general, more pubescence than plants under the conventional lighting system. Growth habits of weeds exposed to the MH lamps were similar to those observed for field growth plants.

The effect of failure in extended and intermittent photoperiodic lighting on the growth of white spruce container seedlings

1985 ◽  
Vol 15 (4) ◽  
pp. 734-737 ◽  
Author(s):  
J. T. Arnott ◽  
C. S. Simmons
Keyword(s):  
Dark Period ◽  
Dry Weight ◽  
White Spruce ◽  
Shoot Length ◽  
Day Length ◽  
Lighting System ◽  
Usual Definition ◽  
Short Day ◽  
Lighting Systems ◽  
Definition Of

White spruce seedlings (seed source, 58°50′ N) were grown in a container nursery at Victoria, B.C. (48°28′ N) under the following two photoperiod regimes: (i) natural day length artifically extended to 18 h (120 lx from an incandescent source); (ii) natural day length with dark period interruption for 2.5 min every 30 min (120 lx from an incandescent source). Beginning on July 17, 12 weeks after sowing, batches of seedlings experienced a simulated failure of the lighting systems of from 0 to 9 nights. Although the reduced photoperiod did not fit the usual definition of a short day, failure of the lighting system in (i) and (ii) caused significant reductions in seedling shoot length and dry weight and a significant increase in root dry weight.

scholarly journals Morphology, Growth, and Rhizome Development of Vaccinium angustifolium Ait. Seedlings, Rooted Softwood Cuttings, and Micropropagated Plantlets

HortScience ◽  
2000 ◽  
Vol 35 (4) ◽  
pp. 738-741 ◽  
Author(s):  
Sharon Morrison ◽  
John M. Smagula ◽  
Walter Litten
Keyword(s):  
Asexual Reproduction ◽  
Dry Weight ◽  
Stem Cuttings ◽  
Vaccinium Angustifolium ◽  
Field Growth ◽  
Lowbush Blueberry ◽  
Rich Media ◽  
Micropropagated Plants ◽  
Growth Habits ◽  
Rhizome Development

For accelerating the filling in of bare areas in native lowbush blueberry fields or converting new areas to production, micropropagated plantlets rooted after three subcultures outperformed seedlings and rooted softwood cuttings. After 2 years of field growth, they averaged 20.3 rhizomes each of average dry weight 3.5 g, as compared with 5.7 rhizomes of average dry weight 1.1 g for rooted softwood cuttings. After 1 year of field growth, seedlings produced on average 3.3 vs. 0.4 rhizomes from micropropagated plants that had not been subcultured and 0.3 rhizomes from stem cuttings. Apparently, subculturing on cytokinin-rich media induces the juvenile branching characteristic that provides micropropagated plants with the desirable morphologies and growth habits of seedlings. These characteristics favor rhizome production while the benefits of asexual reproduction are retained. The advantage in rhizome production of micropropagation over stem cuttings varied among clones.

scholarly journals Lighting Improvement in Building Renovation

2021 ◽  
Vol 1 (1) ◽  
pp. 23
Author(s):  
Syarifah Muthia Putri ◽  
Dina Maizana ◽  
Muhammad Rizal Irhami
Keyword(s):  
Light Intensity ◽  
Lighting System ◽  
Eye Fatigue ◽  
Lighting Systems

Lighting systems that are not up to standard will have an impact on eye fatigue so that the work results of the staff are not optimal. This problem can be solved by designing a lighting system according to the standards that have been determined through the results of previous studies. The 1st floor of the Faculty Engineering, Universitas Medan Area building requires lighting improvements to provide comfort to all staff and lecturers. This research was conducted by measuring the value of light intensity in each room and improving the lighting system which was analyzed through the shape of the room, the color of the walls, and the position of the lights. The results of the study provide additional light points and the position of the lamp according to the utilization. 

scholarly journals Effect of Supplementary Light Intensity on Quality of Grafted Tomato Seedlings and Expression of Two Photosynthetic Genes and Proteins

Agronomy ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 339 ◽  
Author(s):  
Hao Wei ◽  
Jin Zhao ◽  
Jiangtao Hu ◽  
Byoung Ryong Jeong
Keyword(s):  
Light Intensity ◽  
Dry Weight ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Natural Lighting ◽  
Tomato Seedlings ◽  
Photosynthetic Genes ◽  
Supplemental Lighting

Lower quality and longer production periods of grafted seedlings, especially grafted plug seedlings of fruit vegetables, may result from insufficient amounts of light, particularly in rainy seasons and winter. Supplemental artificial lighting may be a feasible solution to such problems. This study was conducted to evaluate light intensity’s influence on the quality of grafted tomato seedlings, ‘Super Sunload’ and ‘Super Dotaerang’ were grafted onto the ‘B-Blocking’ rootstock. To improve their quality, grafted seedlings were moved to a glasshouse and grown for 10 days. The glasshouse had a combination of natural lighting from the sun and supplemental lighting from LEDs (W1R2B2) for 16 h/day. Light intensity of natural lighting was 490 μmol·m−2·s−1 photosynthetic photon flux density (PPFD) and that of supplemental lighting was 50, 100, or 150 μmol·m−2·s−1 PPFD. The culture environment had 30/25 °C day/night temperatures, 70% ± 5% relative humidity (RH), and a natural photoperiod of 14 h as well. Compared with quality of seedlings in supplemental lighting of 50 μmol·m−2·s−1 PPFD, that of seedlings in supplement lighting of 100 or 150 μmol·m−2·s−1 PPFD improved significantly. With increasing light intensity, diameter, fresh weight, and dry weight, which were used to measure shoot growth, greatly improved. Leaf area, leaf thickness, and root biomass were also greater. However, for quality of seedlings, no significant differences were discovered between supplement lighting of 100 μmol·m−2·s−1 PPFD and supplement lighting of 150 μmol·m−2·s−1 PPFD. Expressions of PsaA and PsbA (two photosynthetic genes) as well as the corresponding proteins increased significantly in supplement lightning of 100 and 150 μmol·m−2·s−1 PPFD, especially in 100 μmol·m−2·s−1 PPFD. Overall, considering quality and expressions of two photosynthetic genes and proteins, supplemental light of 100 μmol·m−2·s−1 PPFD (W1R2B1) would be the best choice to cultivate grafted tomato seedlings.

scholarly journals Integration of Natural and Artificial Light on Energy Efficiency of the Mega Bank Makassar Tower Building

2021 ◽  
Vol 4 (1) ◽  
pp. 71-80
Author(s):  
Isty Cahyani Ismail ◽  
Ramli Rahim ◽  
Baharuddin Hamzah
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Light Intensity ◽  
Energy Use ◽  
Energy Savings ◽  
Building Design ◽  
Artificial Light ◽  
Lighting System ◽  
Lighting Systems ◽  
Save Energy

One of the largest energy consumers in the world is buildings. The energy consumption comes from the lighting system. Energy use in buildings is generally 25% for lighting systems. The strategy used in building design is to reduce energy consumption while maintaining the best comfort in a building. The application of energy-saving concepts from the building sector is optimizing the lighting system by integrating natural and artificial lighting systems. This study aims to determine the light intensity in the integrated lighting system of natural and artificial manually and also to find out how much energy can be saved with the integrated lighting system manually. The research location is at the Mega Bank Makassar Tower Building. The research sample was selected by purposive sampling and the sixth floor was chosen as the research location. In this study, simulations were carried out using the DIAlux 4.13 program to integrate natural and artificial light and to calculate the amount of energy efficiency in the workspace. To obtain optimal light intensity and energy savings, a simulation was carried out by turning off half the light points in the workspace, especially the light points around the building openings. The simulation results show that the average integrated lighting quality meets the minimum lighting requirements and can save energy usage by up to 50%. Keywords: energy efficiency; integration lighting; workspace

Luminous Environment and the Perceived Environment

2019 ◽  
pp. 15-21
Author(s):  
Banu Manav
Keyword(s):  
Experimental Studies ◽  
Light Output ◽  
Lighting Design ◽  
Lighting System ◽  
Main Concept ◽  
Healthy Environment ◽  
Perceived Environment ◽  
Efficiency Cost ◽  
Lighting Systems ◽  
User Friendly

In lighting design, the main concept is to achieve a healthy environment, which addresses energy efficiency, cost, maintenance, and quality. User-friendly lighting systems shall be adopted to architecture and interior architecture. User control over the lighting system is important, by dimming or increasing light output, by changing the colour of the light sets the inner atmosphere and affects user mood. Standards and codes on lighting shall also be evaluated by means of these topics. The paper aims to analyse how the luminous environment is affective on the perceived environment. Hence, a series of experimental studies and recent research will be evaluated in regard to understanding and designing luminous environment.

scholarly journals A Supervisory Control Strategy for Improving Energy Efficiency of Artificial Lighting Systems in Greenhouses

Energies ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 202
Author(s):  
Gianluca Serale ◽  
Luca Gnoli ◽  
Emanuele Giraudo ◽  
Enrico Fabrizio
Keyword(s):  
Control Strategy ◽  
Light Emitting Diode ◽  
Cost Savings ◽  
Energy Performance ◽  
Lighting System ◽  
Light Emitting ◽  
Artificial Lighting ◽  
Lighting Control ◽  
Lighting Systems ◽  
Power Densities

Artificial lighting systems are used in commercial greenhouses to ensure year-round yields. Current Light Emitting Diode (LED) technologies improved the system efficiency. Nevertheless, having artificial lighting systems extended for hectares with power densities over 50W/m2 causes energy and power demand of greenhouses to be really significant. The present paper introduces an innovative supervisory and predictive control strategy to optimize the energy performance of the artificial lights of greenhouses. The controller has been implemented in a multi-span plastic greenhouse located in North Italy. The proposed control strategy has been tested on a greenhouse of 1 hectare with a lighting system with a nominal power density of 50 Wm−2 requiring an overall power supply of 1 MW for a period of 80 days. The results have been compared with the data coming from another greenhouse of 1 hectare in the same conditions implementing a state-of-the-art strategy for artificial lighting control. Results outlines that potential 19.4% cost savings are achievable. Moreover, the algorithm can be used to transform the greenhouse in a viable source of energy flexibility for grid reliability.

A field study of fluorescent and LED classroom lighting

2016 ◽  
Vol 50 (4) ◽  
pp. 631-650 ◽  
Author(s):  
N Gentile ◽  
T Goven ◽  
T Laike ◽  
K Sjoberg
Keyword(s):  
Secondary School ◽  
Field Study ◽  
Energy Savings ◽  
Electricity Consumption ◽  
Visual Comfort ◽  
Lighting System ◽  
Upper Secondary ◽  
Lighting Systems ◽  
Indoor Lighting ◽  
Academic Year

Indoor lighting is facing a massive retrofit to LED lighting. Research is needed to assess whether LED-based lighting can promote energy efficiency, boost visual comfort and support biological functions. This field study considered the lighting of four identical classrooms in an upper secondary school in Helsingborg, Sweden. Two classrooms were fitted with state-of-the-art ceiling pendants containing T5 fluorescent tubes and that had a direct/indirect light distribution (the control rooms). The other two classrooms were fitted with an experimental LED indirect lighting system (the experimental rooms). In the classrooms, 72 students aged 17–18 years performed their usual educational activities over a whole academic year. The light environment, electricity consumption, and students’ mood, light perception and saliva cortisol concentration were monitored. The two lighting systems produced only marginal differences. Overall, the experimental rooms were slightly preferred but achieved only small energy savings due to high parasitic losses.

scholarly journals Influences of Shading and Fall Fertilization on Fluorescence, Freeze Resistance, Flower Production and Growth of Rhododendron ×kurume ‘Pink Pearl’

2012 ◽  
Vol 30 (1) ◽  
pp. 28-34
Author(s):  
Frank P. Henning ◽  
Timothy J. Smalley ◽  
Orville M. Lindstrom ◽  
John M. Ruter
Keyword(s):  
Light Intensity ◽  
Dry Weight ◽  
Fertilizer Application ◽  
High Rate ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Freeze Resistance ◽  
Time Period ◽  
Shade Cloth ◽  
Main Plot

We investigated the influences of fall fertilization and light intensity on photosynthesis and freeze resistance of Rhododendron ×kurume ‘Pink Pearl’, an evergreen azalea cultivar, grown outdoors in containers under nursery conditions. The study included two main-plot fall fertilization treatments: 1) 0.5 liter solution containing 75 mg·liter−1 N applied for 60 days from August 1 through September 29 and 2) 0.5 liter solution containing 125 mg·liter−1 N applied for 120 days from August 1 through November 28, and four subplot light intensity treatments 1) 100% ambient photon flux density (PPFD) from May 1, 2004, through May 1, 2005, 2) shade fabric rated to reduce PPFD by 50% from May 1 through September 30, 2004, followed by 100% PPFD from October 1, 2004, through May 1, 2005, 3) 100% PPFD from May 1 through September 30, 2004, followed by 50% PPFD from October 1, 2004, through May 1, 2005, and 4) 50% PPFD from May 1, 2004, through May 1, 2005. Fertilizer application and shade treatments did not interact in their effects on stem freeze resistance or the timing of anthesis. The high rate of extended fertigation (125 mg·liter−1 N applied August 1 through September 28) reduced freeze resistance of azalea stems and advanced anthesis by 4.9 days compared to plants that received moderate fertigation (75 mg·liter−1 N from August 1 through September 29). The high rate of extended fall fertigation failed to increase leaf or stem dry weight compared to plants that received the moderate rate of fertigation. Plants grown in 50% PPFD from May 1 through September 30 produced 163% more above ground dry weight compared to plants grown in 100% light during the same time period. The addition or removal of shade cloth beginning October 1 failed to enhance azalea stem freeze resistance compared to plants that were only exposed to 100 or 50% PPFD respectively. Shade treatments affected the chlorophyll fluorescence ratio (Fv · Fm−1) of leaves, but leaf fluorescence was unrelated to stem freeze resistance. Shade treatments affected azalea growth and photosynthetic stress, but shade neither interacted with fall fertilization to increase stem freeze resistance, nor had a biologically significant effect on stem freeze resistance.

scholarly journals Growth and Yield Response of Rodent Tuber (Typhonium flagelliforme (Lodd.) Blume) under Different Light Intensities and Concentrations of Paclobutrazol

2016 ◽  
Vol 1 (3) ◽  
pp. 29-35
Author(s):  
Noorwitri Utami ◽  
Lukita Devy ◽  
Arief Arianto
Keyword(s):  
Light Intensity ◽  
Concentration Level ◽  
Dry Weight ◽  
Leaf Length ◽  
Growth And Yield ◽  
Yield Response ◽  
Full Sunlight ◽  
Anticancer Treatment ◽  
Main Plot ◽  
Number Of Leaves

Rodent tuber (Typhonium flagelliforme (Lodd) Blume) is one of the medicinal plants used for anticancer treatment, but the information on the cultivation of the plant is limited. The objectives of this research was to study the effect of light intensity and concentration level of paclobutrazol on growth and yield of rodent tuber. This research was conducted at Puspiptek Serpong, Tangerang Selatan, Indonesia. This experiment arranged in a split plot design with three replications. The main plot is light intensity (35, 55, and 100%). The sub plot is concentration level of paclobutrazol (0, 50, 100, and 150 ppm). Paclobutrazol applied as soil drench at one month after planting. In each application 500 ml solution was used. Variables observed consisted of plant height, number of leaves, leaf length, leaf width, leaf and tuber fresh weight; and leaf and tuber dry weight. Data were analyzed using analysis of variance and Duncan Multiple Range test at 5%. The result showed that interaction between light intensity and paclobutrazol affected the whole observed variable. Dry weight of tuber under 35% light intensity was lower than those in other light intensity for all treatments of paclobutrazol. Full sunlight intensity showed better dry weight in all treatments of paclobutrazol. However the dry weight decreasing significantly at 150 ppm paclobutrazol, but still higher than those in 35% light intensity. Therefore, rodent tuber is better cultivated under full sunlight and 55% light intensity with 100 ppm paclobutrazol.

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