When consumers visit garden centers in spring they will most likely buy flowering ornamental plants that are ready for their home gardens. Studies have shown that consumers favor plants that are already in flower rather than those that are "vegetative"—a preference that can present multiple challenges for commercial growers.
To satisfy consumers' wishes, producers of ready-to-flower ornamentals like bedding plants and perennials start growing crops far in advance of the spring buying season, often during the dark and short days of winter. When the days are short, commercial growers turn to "light manipulation" techniques that either promote or prevent flowering in preparation for delivery to markets. New research from a team at Michigan State University offers commercial plant producers a cost-effective method for producing market-ready plants that appeal to both consumers and retailers.
"Long-day" plants are varieties in which flowering is promoted under short periods of darkness, whereas "short-day" plants flower when the dark period exceeds a critical duration. To satisfy spring markets, some commercial ornamental growers create artificial long-day (LD) environments to produce flowering plants for delivery to retailers. Growers employ several methods to promote flowering in LD plants under natural short photoperiods. Methods include extending day length with artificial lighting, shortening the period of darkness by providing night-interruption (NI) lighting, or using cyclic or intermittent lighting during which incandescent lamps are turned on and off at specific intervals for a certain duration.
Matthew G. Blanchard and Erik S. Runkle from the Department of Horticulture at Michigan State designed an experiment to evaluate a technology for long-day lighting for commercial production of ornamentals. The experiment used four popular flowering ornamentals (campanula, coreopsis, petunia, and rudbeckia) to compare the efficacy of a rotating high-pressure sodium lamp (HPS) in promoting flowering with night-interruption lighting using incandescent lamps.
Seedlings were grown under natural short-day photoperiods (12 hours or less) and night-interruption treatments were delivered from a rotating HPS lamp mounted at one gable end of the greenhouse or from incandescent lamps that were illuminated continuously for four hours or cyclically for 6 minutes every 30 minutes for 4 hours. Within 16 weeks, 80% or more of the plants of each species that received night-interruption lighting had a visible flower bud or inflorescence; all species but petunia remained vegetative under the short-day treatment. Flowering of all species grown at 13 meters from the rotating HPS lamp was delayed by 14 to 31 days compared with those under continuous incandescent illumination.
The researchers estimated that the weekly cost to operate night-interruption lighting was an impressive 80% to 83% less than the cost of continuous incandescent lighting. According to Blanchard and Runkle, "a rotating HPS lamp operated continuously during a 4-hour night-interruption was effective at promoting flowering in these long-day species and consumed less energy compared with incandescent lamps operated continuously." The researchers concluded that use of rotating high-pressure sodium lamps could be effective in commercial production as long as the light intensity is above the recommended value.
The complete study and abstract are available on the ASHS HortScience electronic journal web site: http://hortsci.ashspublications.org/cgi/content/abstract/45/2/236
Founded in 1903, the American Society for Horticultural Science (ASHS) is the largest organization dedicated to advancing all facets of horticultural research, education, and application. More information at ashs.org
Michael W. Neff | EurekAlert!
Alkaline soil, sensible sensor
03.08.2017 | American Society of Agronomy
New 3-D model predicts best planting practices for farmers
26.06.2017 | Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
18.08.2017 | Life Sciences
18.08.2017 | Physics and Astronomy
18.08.2017 | Materials Sciences