Search Results

You are looking at 21 - 30 of 179 items for :

  • "supplemental light" x
  • Refine by Access: All x
Clear All
Free access

Caroline S. Donnelly and Paul R. Fisher

The objective was to quantify the effect of supplemental lighting on cutting production for 10 herbaceous annual cultivars. Stock plants of four cultivars (Heliotropium arborescens `Atlantis', Petunia `Supertunia Sun Snow', Scaevola aemula `New Wonder', and Verbena `Tapien Soft Pink') received ambient light [average 6.2 mol·m-2·d-1 photosynthetic photon flux (PPF) during the photoperiod], or ambient light plus either 1.6 or 2.8 mol·m-2·d-1 PPF from high-pressure sodium (HPS) lamps for 11 hours. In a second experiment, the same four species plus six other cultivars were grown under ambient light (average 7.9 mol·m-2·d-1 PPF) or ambient plus 1.9 mol·m-2·d-1 PPF from HPS. The effect of HPS on the production of cuttings varied greatly between species. Growth of Heliotropium was not significantly affected by light level in either experiment. In the first experiment, the addition of 1.6 mol·m-2·d-1 PPF from HPS increased the number of Petunia `Supertunia Sun Snow', Scaevola, and Verbena cuttings by 14%, 51%, and 12%. The addition of 2.8 mol·m-2·d-1 PPF from HPS, increased cuttings harvested from these three species by 23%, 73%, and 22% respectively. In the second experiment, Petunia `Supertunia Sun Snow', Scaevola, Aloysia triphylla (lemon verbena), and Osteospermum `Lemon Symphony' had a positive cutting production response to HPS (17% to 45% increase), whereas cutting numbers of other species (Argyranthemum `Summer Melody', Lantana `Patriot Firewagon', Impatiens New Guinea hybrid `Pedro', Petunia `Supertunia Blue Wren', and Verbena) were not significantly affected by HPS. In both experiments, cutting quality (length, stem caliper, fresh mass, and dry mass) and subsequent rooting of cuttings were not significantly affected by light level.

Free access

Hiroshi Hamamoto and Keisuke Yamazaki

Long-day treatment with supplemental lighting (i.e., night break or day extension) can be used to control the flowering of plant species in which reproductive stage is influenced by photoperiod. The effect of supplemental light quality on long

Free access

Vincent Martineau, Mark Lefsrud, Most Tahera Naznin, and Dean A. Kopsell

. light in moles per meter 2 . Normalized plant production values assumed equal plant biomass production from natural and artificial light and calculated production rates based on the percentage of supplemental light vs. total light (dry mass produced by

Free access

Michael P. Dzakovich, Celina Gómez, and Cary A. Mitchell

-HPS lamps (PL Lighting Systems, Beamsville, ON), or natural solar radiation plus supplemental light from IC-LED towers (ORBITEC, Madison, WI). The IC-LED towers emitted red (peak wavelength = 627 nm) and blue (peak wavelength = 450 nm) light with a 95:5 red

Free access

Veronica A. Hutchinson, Christopher J. Currey, and Roberto G. Lopez

were provided with supplemental light (≈4 to 5 mol·m −2 ·d −1 ) during the last two-thirds or entire young plant stage, shoot dry mass and number of leaves increased, whereas subsequent time to flower decreased. Similarly, increasing propagation DLI

Free access

Christopher J. Currey and Roberto G. Lopez

.8 ± 10.9, 49.2 ± 4.5, and 27.8 ± 1.7 μmol·m −2 ·s −1 , respectively, at plant height [as measured with a quantum sensor (LI-COR Biosciences)], respectively, from 0600 to 2200 hr ( Table 2 ). Supplemental light was delivered from HPS lamps (e-system HID

Free access

Christopher J. Currey, Veronica A. Hutchinson, and Roberto G. Lopez

providing supplemental light to achieve 10 mol·m −2 ·d −1 , although the amount of supplemental lighting necessary will vary with greenhouse structure, location, and time of year. Our results expand the general understanding of how increasing the DLI during

Open access

Chase Jones-Baumgardt, David Llewellyn, and Youbin Zheng

spectrum treatments in greenhouse environments ( Bantis et al., 2018 ) where comparable supplemental light intensities (LIs) have yielded similar crop productivity metrics for LED vs. HPS in many commodities ( Currey and Lopez, 2013 ; Hernández and Kubota

Open access

Hunter A. Hammock, Dean A. Kopsell, and Carl E. Sams

supplemental light at 8.64 mol·m −2 ·d −1 (100 µmol·m −2 ·s −1 , 24 h·d −1 ). Dry leaf, shoot, and main stem weight were evaluated separately across light treatments using Tukey’s protected least significant difference, and data for each followed by the same

Free access

Gwendolyn Hartley and Robert G. Anderson

Satin flower (Clarkia amoena subsp. whitneyi; syn. Godetia whitneyi) is a cool temperature, high light plant used as a cutflower in Japan, Europe and California. The stiking flower color patterns, large, long-lasting flowers and branching pattern could make this plant an important potted flowering plant. Cuttings, 6-8 cm long with flower buds (0.5-2.0 cm long), were harvested from secondary and tertiary stems of field-grown pinched plants of `Grace Red'. Cuttings were rooted in intermittent mist and potted in 10 cm pots two weeks later. The terminal flower buds and stem tip were removed one week later and the plants flowered within 4 weeks with 4-6 equal lateral branches. In the fall, `Grace Rose Pink' seed was sown Oct. 4, 1989, plants were grown under 100 umole s-1 cm-2 HPS 18 hr. supplemental light. Cuttings from the primary stem were harvested at the same stage, rooted in two weeks, potted and pinched one week later. Cuttings grown under supplemental light flowered 4 weeks later while cuttings grown under ambient light flowered over 10 weeks later. Over 70% of the terminal cuttings in supplemental light were 22-30 cm tall with 4-6 equal lateral branches that flowered uniformly.