scholarly journals Influence of Cultivar and Seasonal Growing Environment on Growth and Postharvest Characteristics of Single-shoot Pot Rose Plants

HortScience ◽  
2004 ◽  
Vol 39 (1) ◽  
pp. 138-141
Author(s):  
José Antonio Saraiva Grossi ◽  
H. Brent Pemberton ◽  
Harvey J. Lang
Keyword(s):  
Photon Flux ◽  
Controlled Environment ◽  
Flower Longevity ◽  
Photosynthetic Photon Flux ◽  
Fluorescent Lamps ◽  
Flower Diameter ◽  
Single Shoot ◽  
Growing Environment ◽  
Growth Chambers ◽  
Growing Conditions

Rooted liners of pot rose (Rosa L.) cultivars Meiferjac, Meigagul, Meighivon, Meishulo, Ruijef, Ruidodo, and Ruirosora were used to study the influence of cultivar and seasonal growing environment on growth and postharvest performance. Single-shoot plants were grown in controlled environment chambers simulating summer (30 °C day/21 °C night cycle with a 14-hour photoperiod) and winter (21 °C day/16 °C night cycle with a 10-hour photoperiod) greenhouse growing conditions. At flower developmental stage 2 (showing color, calyx reflexing, no petals reflexed), the plants were placed in a continuously lighted simulated interior evaluation room at 21 ± 1 °C under 15 μmol·m-2·s-1 photosynthetic photon flux from cool-white fluorescent lamps for postharvest evaluations. Plants had quicker flowering, smaller flower diameter, more compact growth, and smaller leaf area when grown under the summer environment compared to the winter environment. Most cultivars exhibited greater flower longevity on summer-grown plants when compared to winter-grown ones. `Ruirosora' did not exhibit this difference due to exceptional longevity on winter-grown plants. Also, the use of single-shoot plants was shown to be a potentially useful way to increase replication in small growing environments such as growth chambers.

scholarly journals CAN PLANTS DETECT SMALL DIFFERENCES IN IRRADIANCE OBTAINED BY VARYING THE REFLECTANCE PROPERTIES OF THE GROWTH CHAMBER WALLS?

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 656b-656
Author(s):  
Donald T. Krizek ◽  
Roman M. Mirecki ◽  
Alton L. Fleming
Keyword(s):  
Shoot Elongation ◽  
Growth Chamber ◽  
Photon Flux ◽  
Controlled Environment ◽  
Wall Surface ◽  
Photosynthetic Photon Flux ◽  
Fluorescent Lamps ◽  
Environment Study ◽  
Growth Chambers

A controlled-environment study was conducted in separate growth chambers with the wall surface covered either with white enamel paint (WEP) or polished aluminum (PA). `Williams' soybean were grown under 1500 mA cool white fluorescent lamps and internodes measured at 7, 14, and 21 days. Photosynthetic photon flux (PPF) levels in the center of each chamber were set at 320 μmol m-2 s-1 with a quantum sensor. Means ± SD for PPF levels in the WEP and PA chambers were 286 ± 28 and 307 ± 11 μmol m-2 s-1, respectively. This increase in mean PPF and decrease in variance of PPF in the PA chamber was reflected in: a) a decrease in hypocotyl, first internode, and total shoot elongation: and b) an increase in enlargement of the primary and the first trifoliolate leaves. These findings demonstrate that plants can detect small differences in irradiance within a growth chamber and suggest the advantages of using a highly polished wall surface to improve uniformity of irradiance and reduce variability in growth.

scholarly journals Vernalization Duration and Light Intensity Influence Flowering of Three Hybrid Nobile Dendrobium Cultivars

HortScience ◽  
2011 ◽  
Vol 46 (3) ◽  
pp. 406-410 ◽  
Author(s):  
Min Lin ◽  
Terri W. Starman ◽  
Yin-Tung Wang ◽  
Genhua Niu
Keyword(s):  
Light Intensity ◽  
Flowering Time ◽  
Photon Flux ◽  
Flower Initiation ◽  
Flower Longevity ◽  
Photosynthetic Photon Flux ◽  
Flower Diameter ◽  
Flower Quality ◽  
Delayed Flowering

The flowering time and flower quality of three hybrid Dendrobium nobile cultivars in relation to light intensity during cooling and duration of vernalization were studied in the first experiment. Mature Dendrobium Red Emperor ‘Prince’, Den. Sea Mary ‘Snow King’, and Den. Love Memory ‘Fizz’ plants were vernalized at 10 °C under 300 to 350 μmol·m−2·s−1 photosynthetic photon flux (PPF) (12-h photoperiod) or darkness, each with four cooling durations (2, 4, 6, or 8 weeks). Plants were forced in a greenhouse after vernalization. At least 4 weeks of 10 °C cooling in light was needed for complete flower initiation of Den. Red Emperor ‘Prince’, whereas Den. Sea Mary ‘Snow King’ and Den. Love Memory ‘Fizz’ only needed 2 weeks of 10 °C cooling regardless of light. For all three cultivars, darkness during vernalization slightly delayed flowering and resulted in fewer but larger flowers. Longer cooling duration delayed flowering, decreased flower longevity, and produced more and larger flowers. In a second experiment, Den. Love Memory ‘Fizz’ plants were vernalized at 15 °C for 4 weeks under a 12-h photoperiod and PPF of 0, 50, 100, or 200 μmol·m−2·s−1. Compared with 200 μmol·m−2·s−1, low PPF at 50 or 100 μmol·m−2·s−1 did not affect flowering time or flower qualities; however, darkness delayed flowering and reduced flower qualities except flower diameter.

scholarly journals 093 Miniature Rose Flower Longevity in Response to Ethylene Is Not Affected by Seasonal Growing Conditions

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 404E-404
Author(s):  
Jose Antonio S. Grossi ◽  
H. Brent Pemberton ◽  
William E. Roberson
Keyword(s):  
Developmental Stage ◽  
Fluorescent Light ◽  
Controlled Environment ◽  
Flower Longevity ◽  
Ethylene Concentration ◽  
Growth Chambers ◽  
The Difference ◽  
Exogenous Ethylene ◽  
Growing Conditions ◽  
Interior Environment

The effect of exogenous ethylene was investigated on single-stemmed plants of Rosa L. `RUIdodo', `RUIrosora', `RUIjef', `MEIferjac', `MEIshulo', `MEIghivon' and `MEIgagul' grown in controlled environment growth chambers simulating summer-like and winter-like conditions. When the flower on each plant reached developmental stage 2 (showing color, calyx reflexing, no petals reflexed), the plants were placed for 18 h in plexiglass chambers with ethylene at 0, 0.1, 0.5, 1.0 and 5.0 μL·L-1 under a simulated interior environment at 21 °C with 14 μmol·m-2·s-1 fluorescent light. Under the same interior environment, the plants were kept for postharvest evaluation. Response to ethylene of all cultivars was not affected by the difference in growing conditions. As shown previously by other authors, however, the ethylene reduced flower longevity. Treatment with 0.1 μL·L-1 of ethylene reduced flower longevity by 1 day in comparison to the control (0 μL·L-1). The ethylene concentrations of 1.0 μL·L-1 and 5.0 μL·L-1 reduced flower longevity by 3 days. Regardless of ethylene concentration or growing conditions, `RUIjef' and `MEIferjac' exhibited the longest flower longevity and `MEIghivon' and `MEIgagul' the shortest flower longevity. All cultivars, except `RUIrosora', exhibited the longest flower longevity under summer-like vs. winter-like conditions, with the difference ranging from 1.5 to 5 days. `RUIrosora' exhibited similar flower longevity regardless of growing conditions. Differences in flower longevity in response to seasonal growing conditions have been found by us and other authors, but the cultivars used in this study have not been previously studied. This difference in flower longevity as a response to growing conditions cannot be explained by differences in response to ethylene so that other factors must be involved.

scholarly journals Effects of Photosynthetic Photon Flux, Photoperiod, and CO2 Enrichment on the Growth and Morphogenesis of Lettuce Plug Transplants

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 542E-543
Author(s):  
Yoshiaki Kitaya ◽  
Genhua Niu ◽  
Maki Ohashi ◽  
Toyoki Kozai
Keyword(s):  
Co2 Enrichment ◽  
Dry Weight ◽  
High Light Intensity ◽  
Leaf Length ◽  
Plant Production ◽  
Photon Flux ◽  
Controlled Environment ◽  
Photosynthetic Photon Flux ◽  
Artificial Lighting ◽  
Fluorescent Lamps

Artificial lighting is widely used in controlled environment plant production to enhance plant growth and quality. However, high light intensity with artificial lighting is costly, and often causes increase of leaf temperature and, thus, leaf burn. We investigated the effects of photosynthetic photon flux (PPF) and photoperiod on the growth and morphogenesis of lettuce plug transplants under ambient and enriched CO2 levels. Three days after seeding, the plants were cultured under four PPF levels (100, 150, 200, and 300 μmol·m–2·s–1), two photoperiods (16 and 24 hr), and two CO2 levels (400 and 800 μmol·mol–1) for 18 days in growth chambers. Light source was fluorescent lamps. The air temperature around the plants was kept at 20°C. The results showed that dry weight of the plants increased linearly as PPF and daily integrated PPF (product of PPF and photoperiod) increased under both CO2 levels. At the same daily integrated PPF, higher CO2 level and longer photoperiod led to higher dry weight of the plants. CO2 enrichment increased significantly dry weight of the plants. The ratio of T/R and specific leaf area of the plants decreased quadratically as daily integrated PPF increased under both CO2 levels. The ratio of leaf length to leaf width of the plants decreased quadratically as PPF increased under the two photoperiods and CO2 levels.

scholarly journals Application of Microbubbles to Hydroponics Solution Promotes Lettuce Growth

2009 ◽  
Vol 19 (1) ◽  
pp. 212-215 ◽  
Author(s):  
Jong-Seok Park ◽  
Kenji Kurata
Keyword(s):  
Nutrient Solution ◽  
Growth Promotion ◽  
Photon Flux ◽  
Photosynthetic Photon Flux ◽  
Fluorescent Lamps ◽  
Promote Plant Growth ◽  
Lettuce Growth ◽  
Leaf Lettuce ◽  
Charged Ions ◽  
Positively Charged

We investigated the effects of microbubbles, generated by a swivelling microbubble generator in hydroponics nutrient solution, on the growth of leaf lettuce (Lactuca sativa). Twenty-four lettuce seedlings at the four- to five-leaf stage each were transplanted into two culture containers at 21 ± 1 °C (day) and 18 ± 1 °C (night) under fluorescent lamps that provided a photosynthetic photon flux of 173 ± 18 and 171 ± 16 μmol·m−2·s−1 averaged at eight points at the canopy level for micro- and macrobubbles conditions, respectively, during a photoperiod of 16 h per day. Seedlings were cultivated for 2 weeks in two deep flow technique (DFT) hydroponics culture systems in which micro- or macrobubbles were produced, respectively, by a microbubble aerator and aquarium aeration stones. The nutrient solution was maintained at a temperature of 22 ± 1 °C during the experiment. Fresh and dry weights of the microbubble-treated lettuce were 2.1 and 1.7 times larger, respectively, than those of the macrobubble-treated lettuce. Although the reasons for growth promotion by microbubbles are still under investigation, we speculate that the larger specific surface area of the microbubbles and negative electronic charges on the microbubbles surfaces may promote growth because microbubbles can attract positively charged ions that are dissolved in the nutrient solution. These results indicate that microbubbles generated in a DFT hydroponics culture system can remarkably promote plant growth.

scholarly journals Pre-Harvest UV-B Radiation and Photosynthetic Photon Flux Density Interactively Affect Plant Photosynthesis, Growth, and Secondary Metabolites Accumulation in Basil (Ocimum Basilicum) Plants

Agronomy ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 434 ◽  
Author(s):  
Haijie Dou ◽  
Genhua Niu ◽  
Mengmeng Gu
Keyword(s):  
Phenolic Compounds ◽  
Flux Density ◽  
Photosynthetic Photon Flux Density ◽  
Ocimum Basilicum ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Yield Reduction ◽  
Controlled Environment ◽  
Photosynthetic Photon Flux ◽  
Plant Yield

Phenolic compounds in basil (Ocimum basilicum) plants grown under a controlled environment are reduced due to the absence of ultraviolet (UV) radiation and low photosynthetic photon flux density (PPFD). To characterize the optimal UV-B radiation dose and PPFD for enhancing the synthesis of phenolic compounds in basil plants without yield reduction, green and purple basil plants grown at two PPFDs, 160 and 224 μmol·m−2·s−1, were treated with five UV-B radiation doses including control, 1 h·d−1 for 2 days, 2 h·d−1 for 2 days, 1 h·d−1 for 5 days, and 2 h·d−1 for 5 days. Supplemental UV-B radiation suppressed plant growth and resulted in reduced plant yield, while high PPFD increased plant yield. Shoot fresh weight in green and purple basil plants was 12%–51% and 6%–44% lower, respectively, after UV-B treatments compared to control. Concentrations of anthocyanin, phenolics, and flavonoids in green basil leaves increased under all UV-B treatments by 9%–18%, 28%–126%, and 80%–169%, respectively, and the increase was greater under low PPFD compared to high PPFD. In purple basil plants, concentrations of phenolics and flavonoids increased after 2 h·d−1 UV-B treatments. Among all treatments, 1 h·d−1 for 2 days UV-B radiation under PPFD of 224 μmol·m−2·s−1 was the optimal condition for green basil production under a controlled environment.

scholarly journals Shoot Growth Rate and Density Affect Bud Necrosis of `Riesling' Grapevines

1995 ◽  
Vol 120 (6) ◽  
pp. 989-996 ◽  
Author(s):  
Tony K. Wolf ◽  
M. Kay Warren
Keyword(s):  
Growth Rate ◽  
Positive Relationship ◽  
Shoot Growth ◽  
Growth Retardant ◽  
Photon Flux ◽  
Photosynthetic Photon Flux ◽  
Dormant Bud ◽  
High Incidence ◽  
Shoot Growth Rate ◽  
Growing Conditions

Examination of `Riesling' grape (Vitis vinifera L.) in Virginia suggested that a high incidence of bud necrosis (BN) in some vineyards was associated with canopy shade and rapid shoot growth. BN appeared to originate as an abortion and dehydration of the primary, and occasionally secondary, buds of the developing dormant bud. BN frequency was lowest among the basal four nodes of a given shoot or cane, and increased in frequency through node 20. Experiments were conducted in 1991 and 1992 to evaluate the specific involvement of shoot growth rate and canopy shade on `Riesling' BN. Shoot growth rate (SGR), measured in a 17-day period around bloom, had a significant, positive relationship with BN in one of two vineyards. BN was positively associated with cane diameter and average internode length. Applying the growth retardant paclobutrazol significantly reduced SGR and BN incidence up to 80% among nodes 6 to 15 in two separate vineyards. Artificial shade (64% or 92% reduction in photosynthetic photon flux), suspended over vine canopies in the 3-week period before véraison, did not affect BN. Shoots of canopies that had been thinned before bloom to 10 shoots/m of canopy expressed slightly lower BN levels than shoots sampled from canopies that had been thinned to 20 shoots per meter. `Riesling' BN appeared more influenced by shoot vigor than shade under Virginia growing conditions. Chemical name β-[(4-chlorophenyl)methyl]-α-(1,1-dimethyl-ethyl)-1H-1,2,4-triazole-1-ethanol (paclobutrazol).

scholarly journals The Effect of Light Intensity before Harvest on Phenethyl Isothiocyanate Concentration in Watercress (Nasturtium officinale R.Br.) Depends on Photoperiod

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 578d-578 ◽  
Author(s):  
Usha Palaniswamy ◽  
Richard McAvoy ◽  
Bernard Bible
Keyword(s):  
Light Intensity ◽  
Dry Mass ◽  
Photon Flux ◽  
Phenethyl Isothiocyanate ◽  
Photosynthetic Photon Flux ◽  
Nasturtium Officinale ◽  
Growth Chambers ◽  
Effect Of Light

Watercress plants were grown in growth chambers at 15°C or 25°C and either an 8- or 12-hour photoperiod (PP). The photosynthetic photon flux (PPF) was 265 μmol·m–2·s–1 in all chambers, but beginning 1 week before harvest, half of the plants in each chamber were subjected to a higher PPF (434 μmol·m–2·s–1). At harvest, watercress leaves and stems were analyzed for phenethyl isothiocyanate (PEITC) content. Watercress grown at 25°C, the 12-hour PP, and 1 week of high PPF produced the highest PEITC concentration in leaves and stems, and plants grown at 15°C, the 8-hour PP, and the low PPF until harvest produced the lowest PEITC concentration. Plants grown at the 8-hour PP, then exposed to 1 week of high PPF, produced 57.3% and 45.9% greater PEITC at 25 and 15°C, respectively, then plants exposed to the low PPF until harvest. However, plants grown at the 12-hour PP and subjected to 1 week of high PPF produced PEITC levels similar to plants grown under the low PPF at 25 and 15°C. At 25°C, plants grown under the low PPF and the 12-hour PP produced 62% greater dry mass than plants exposed to 1 week of high PPF and the 8-hour PP, but did not differ in PEITC content. Thus, the effect of 1 week of high PPF on PEITC concentration depended on photoperiod.

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 Survival of Young Cold-hardened `Hamlin' Orange Trees at – 6.7C

HortScience ◽  
1990 ◽  
Vol 25 (1) ◽  
pp. 98-99 ◽  
Author(s):  
George Yelenosky
Keyword(s):  
Oxygen Uptake ◽  
Citrus Sinensis ◽  
Photon Flux ◽  
Controlled Environment ◽  
Photosynthetic Photon Flux ◽  
Test Room ◽  
Rough Lemon ◽  
Tree Survival ◽  
Freeze Test ◽  
Orange Trees

Potted greenhouse-grown, l-year-old `Hamlin' orange [Citrus sinensis (L.) Osbeck] trees on 1.5-year-old rough lemon (C. jambhiri Lush.) rootstock were temperature-conditioned for 6 consecutive weeks in a controlled-environment room to test cold-hardening ability. Holding at 15.6 ± 0.6C during 12-hr days [425 μmol·s-1·m-2 photosynthetic photon flux (PPF) at top of trees] and 4.4C during nights resulted in 100% tree survival and no leaf loss “after 4 hr of – 6.7C in a dark freeze test room. Unhardened greenhouse trees were killed to rootstock. Solute efflux (dS·m-1) from unhardened frozen leaves was > 20-fold that from frozen leaves on hardened trees and nonfrozen leaves on unhardened trees. Oxygen uptake was not significantly impaired in frozen hardened leaves. No 02 uptake was evident for frozen unhardened leaves.

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