scholarly journals 766 PB 316 INFLUENCE OF PHOTOPERIOD AND LIGHT INTENSITY ON PLANT HEIGHT OF LILIUM LONGIFLORUM THUNB

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 542f-542
Author(s):  
Theo J. Blom ◽  
M.J. Tsujita ◽  
Glen L. Roberts
Keyword(s):  
Light Intensity ◽  
Plant Height ◽  
Lilium Longiflorum ◽  
Light Period ◽  
Ambient Light ◽  
Dark Light ◽  
Light Reduction ◽  
Potted Plants

Potted plants of Lilium longiflorum Thunb. cvs. `Ace' and `Nellie White' were grown either under an ambient photoperiod (APP) or under an 8-hour photoperiod (8PP) in a greenhouse. The latter photoperiod was achieved by pulling black cloth over the plants at 1615HR and removing the cloth at 0615HR each day, from emergence to flowering. Within each photoperiod, ambient light intensity was reduced by 0, 20, 40 or 60% using various shade cloths permanently suspended above the plants. Heating was set at 20/16C for the dark/light period, respectively. Plant height, determined from the rim of pot to the top of plant, was 25% lower under 8PP compared to APP for both cultivars. Plant height of `Ace' and `Nellie White' increased by 1.5 mm and 2.5 mm, respectively, per 1% light reduction.

scholarly journals 568 Effect of Twilight and Temperature Difference (DIF) or Temperature Pulse at End-of-day on Height of Easter Lilies

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 544C-544
Author(s):  
Theo J. Blom ◽  
David Kerec
Keyword(s):  
Plant Height ◽  
Temperature Difference ◽  
Lilium Longiflorum ◽  
Light Period ◽  
Night Temperature ◽  
Temperature Pulse ◽  
Low Intensity ◽  
Snow White ◽  
Significant Difference ◽  
Red Radiation

Potted bulbs of Lilium longiflorum Thunb. `Ace', `Nellie White', and `Snow White' were grown under either ambient photo period (APP), 8-h photo period using blackout (no twilight) between 1600 and 0800 HR (8PP) or 8PP extended with 1-h of low-intensity far-red radiation (9PP) at end-of-light period in a greenhouse with either a +5 °C DIF or a –5 °C DIF (= day – night temperature). In a second experiment, Easter lilies were also grown under APP, 8PP, and 9PP regimes with a constant day/night temperature (0 °C DIF) but with either a +5 °C or –5 °C temperature pulse for 3-h during end-of-light period. Each experiment was replicated twice and data was averaged over 2 years. The +5 °C DIF regime produced plants which were 19% taller than under –5 °C DIF. Plants grown under APP were 32% and 25% taller than under 8PP in the +5 °C and –5 °C DIF regimes, respectively. Regardless of the DIF regime, plant height under the 9PP was the same. In the second experiment, there was no significant difference in plant height of plants grown with the –5 °C compared with the +5 °C pulse at end-of-light period.

SEXUAL BEHAVIOUR OF THE MEDITERRANEAN FLOUR MOTH, ANAGASTA KÜHNIELLA: SOME INFLUENCES OF AGE, PHOTOPERIOD, AND LIGHT INTENSITY

1970 ◽  
Vol 102 (5) ◽  
pp. 534-540 ◽  
Author(s):  
R. M. M. Traynier
Keyword(s):  
Sex Pheromone ◽  
Light Intensity ◽  
Organic Solvents ◽  
Sexual Behaviour ◽  
Light Period ◽  
Unmated Female ◽  
Diel Cycles ◽  
The Mediterranean ◽  
Old Females ◽  
Mediterranean Flour Moth

AbstractUnmated female A. kühniella (Zell.) emitted a sex pheromone at the beginning of the light period of a 24 hour cycle of light and dark periods. There were no differences apparent in the duration of the calling posture by females in light of 1, 40, or 200 lux. A sex pheromone was extracted from the abdominal tips of unmated females of various ages with organic solvents, 3-day-old females gave the most potent extracts. Extracts of equal potence were obtained from females at different times during the diel cycles of photoperiod. The response of males to the extract was maximal at dawn, increased with age for 5 days, and was greater in light of 1 lux intensity than of 200 lux. Both sexes showed an anticipation of the beginning of the light period in their sexual behaviour, but if the timing of the cycle of photoperiod was changed the behaviour of both sexes became synchronised to the new cycle on its second or third occurrence.

Ambient light intensity and direction determine relative attractiveness of yellow traps toRhagoletis indifferens(Diptera: Tephritidae)

2015 ◽  
Vol 147 (6) ◽  
pp. 776-786 ◽  
Author(s):  
W.L. Yee
Keyword(s):  
Light Intensity ◽  
Fruit Fly ◽  
Ambient Light ◽  
Laboratory Results ◽  
Yellow Traps ◽  
Relative Attractiveness ◽  
Variable Light ◽  
Sunlight Intensity ◽  
Trap Placement ◽  
Tephritid Fruit Flies

AbstractUnderstanding factors that influence attraction of tephritid fruit flies (Diptera: Tephritidae) to objects can lead to development of more sensitive traps for fly detection. Here, the objective was to determine if differences in attractiveness between two sticky yellow rectangle traps to western cherry fruit fly,Rhagoletis indifferensCurran, depend on ambient light intensity and direction. The translucent plastic Yellow Sticky Strip (YSS) was compared with the less translucent yellow cardboard Alpha Scents (AS). Flies were released inside a box or cage opposite a trap or traps illuminated from outside at different intensities to generate variable light passage. Regardless of type, the trap with greatest light passage was most attractive. When the same light intensity was shone on both traps, the YSS, which allowed greater light passage, was more attractive than the AS. When the light was inside a cage and shone onto the two traps in the same direction as approaching flies, the AS reflected more light and was more attractive. A field experiment generally supported light passage effects seen in the laboratory. Results suggest trap placement with respect to sunlight intensity and direction affects light passage and the attractiveness of yellow traps toR. indifferens.

scholarly journals Effects of Photosynthetic Activity Radiation (PAR) on Green Mustard Plant Growth (Brassica rapa var. parachinensis L.)

2019 ◽  
Vol 20 (1) ◽  
pp. 19
Author(s):  
Ni Nyoman Ratini ◽  
I Wayan Supardi ◽  
Yuli Nurfadhillah
Keyword(s):  
Growth Rate ◽  
Light Intensity ◽  
Plant Height ◽  
Photosynthetic Activity ◽  
Plant Biomass ◽  
Vegetative Phase ◽  
Active Radiation ◽  
Blue Filter ◽  
Mustard Plant ◽  
Number Of Leaves

A research on the effect of photosynthetic active radiation (PAR) on the growth of green mustard plants has been conducted. The radiation source used is sunlight. Samples have been grouped as a sample which treated by red filter (P1), by orange filter (P2), by purple filter (P3), by green filter (P4), by blue filter (P5) and a sample without filter as a control (P0). Each sample consisted of four plants. The planting was carried out using polybags with compost media. Observations were made from the nursery phase to the slow vegetative phase (day 3rd, when all plants had grown shoots until day 63rd of the harvest). Parameters measured include light intensity, plant height and number of leaves. Measurement is done every three days. Also it measured plant biomass on the last day of observation (63rd day). The results showed that the intensity of each sample had an impact on the harvest. The best growth rate is obtained in P2, both in the nursery phase and fast vegetative phase i.e. 0.119 cm/day and 0.194 cm/day, respectively. While the highest growth rate was obtained in the P3 sample, namely the slow vegetative phase (0.035 cm/day). Overall the best planting results were obtained in P2 samples with plant height of 23.18 cm, number of leaves of 12 strands and plant biomass of 33.56 g.

scholarly journals Assessment of Growth Characteristics of Medicinal Plants Ocimum tenuiflorum L. and Plectranthus amboinicus (Lour.) Spreng. Under Shade Net and Open Conditions

2020 ◽  
pp. 1-8
Author(s):  
J. Ambujavalli ◽  
K. Santhiya ◽  
K. Rohini ◽  
V. Kumaresan
Keyword(s):  
Medicinal Plants ◽  
Leaf Area ◽  
Plant Height ◽  
Growth Characteristics ◽  
Similar Type ◽  
Potted Plants ◽  
Ocimum Tenuiflorum ◽  
Number Of Leaves ◽  
Plectranthus Amboinicus ◽  
Microclimate Conditions

Aim: To study the effect of shade net on the growth characteristics of two medicinal plants viz., Tulsi and Indian Borage in terms of plant height, number of leaves, leaf area and flowering in relation to open condition. Place and Duration of Study: Lawspet, Puducherry, India between June 2018 and October 2018. Methodology: Tulsi and Indian Borage plants were grown in similar type of soil. The potted plants were kept in open, 35% and 75% shade net conditions and studied for 3 months. The plant height, number of leaves, and leaf area were measured including number of inflorescence branches for Tulsi. Results: The average air temperature was lower under shade net. Relative humidity was more in shade net conditions with maximum in 75% shade and least in open conditions. The number of leaves of Tulsi and Indian Borage recorded was maximum when grown under 35% shade and least in open conditions. Plant height was maximum in 75% shade for Tulsi and 35% shade in Indian Borage and least in open conditions on both the cases. Leaf area was maximum for both Tulsi and Indian Borage in 75% shade. Conclusion: Growth of the two medicinal plants was influenced by the microclimate conditions. The present study shows that the medicinal plants can be grown in shade net conditions to increase the yield of medicinally useful parts.

scholarly journals Optimizing rearing and welfare in Senegalese sole (Solea senegalesensis) broodstock: Effect of ambient light intensity and handling time on stress response

2020 ◽  
Vol 222 ◽  
pp. 104880 ◽  
Author(s):  
Filipe Figueiredo ◽  
Cláudia Aragão ◽  
Wilson Pinto ◽  
Maria Teresa Dinis ◽  
Catarina C.V. Oliveira
Keyword(s):  
Stress Response ◽  
Light Intensity ◽  
Handling Time ◽  
Senegalese Sole ◽  
Ambient Light

The effects of handling time, ambient light, and anaesthetic method, on the standardized measurement of fish colouration

2011 ◽  
Vol 68 (2) ◽  
pp. 330-342 ◽  
Author(s):  
Suzanne M. Gray ◽  
Francine L. Hart ◽  
Maude E.M. Tremblay ◽  
Thomas J. Lisney ◽  
Craig W. Hawryshyn
Keyword(s):  
Light Intensity ◽  
Spectral Reflectance ◽  
Handling Time ◽  
Ambient Light ◽  
Clove Oil ◽  
Ambient Conditions ◽  
Light Levels ◽  
Standardized Measurement ◽  
Colour Patterns ◽  
Reflectance Data

The effects of handling time, ambient light intensity, and anaesthetic method, on the collection of spectral reflectance data were assessed in two species of Malawi cichlids ( Melanochromis auratus and Metriaclima zebra ). Using spectrometry, colour patches were measured over 10 min, under increasing ambient light levels, and using three anaesthetic methods. As time elapsed, maximum percent reflectance (Rmax) decreased across all anaesthetic methods and species, suggesting that measurements should be taken immediately after capture and anaesthetization. With increasing light intensity, Rmax increased significantly, suggesting that measurements should be taken under natural ambient conditions when possible. Finally, we found that anaesthetizing fish using an ice bath produced significantly higher Rmax than using either MS-222 (tricaine methanesulphonate) or clove oil (eugenol). However, the highest proportion of ultraviolet (UV) colouration was recorded while fish were anaesthetized with clove oil. Our results highlight the variation involved in measuring fish colour patterns using two related species, and thus indicate the need for a standardized approach to collecting spectral reflectance data in fish.

Diel Periodicity of Chlorophyll a Concentration in Oregon Coastal Waters

1972 ◽  
Vol 29 (9) ◽  
pp. 1253-1259 ◽  
Author(s):  
Walter A. Glooschenko ◽  
Herbert Curl Jr. ◽  
Lawrence F. Small
Keyword(s):  
Light Intensity ◽  
Chlorophyll A ◽  
Coastal Waters ◽  
Dark Period ◽  
Skeletonema Costatum ◽  
Time Of Day ◽  
Light Period ◽  
Diel Periodicity ◽  
Low Light ◽  
Chlorophyll Precursor

Concentrations of chlorophyll a in phytoplankton exhibited a diel periodicity in Oregon coastal waters. Maximum surface concentrations often occurred around midnight and highest 25-m concentrations early in the evening (or even in late afternoon). Concentrations at intermediate depths fell in between and in a predictable progression with depth and time of day. Minimum chlorophyll a values occurred in the afternoon. No definite periodicity was established at 50 m.Laboratory studies with Skeletonema costatum demonstrated that the diel cycle of chlorophyll a per cell was related to the light intensity and duration to which cells were exposed. Highest concentrations of this pigment occurred early in the dark period and lowest concentrations in the light period when cells were grown under photoperiods of 9, 12, and 15 hr at a light intensity of approximately 1200 ft-c. Pigment bleaching probably was responsible for the low concentrations during the light period. The decline of chlorophyll a from the maximum early in the dark period began after the cells possibly became deficient in some chlorophyll precursor or energy-yielding substrate. Addition of an external carbon source during the dark period prolonged the high chlorophyll a concentrations in the dark before the decline began. Under low light (400 ft-c) chlorophyll a synthesis occurred only in the light. This phenomenon was most likely due to an insufficient amount of energy-yielding substrate or precursor synthesized during the low-light period, and the lack of bleaching in the light period at this lower intensity. The laboratory results were consistent with interpretations of the field data. A correction for diel pigment periodicity is recommended for models estimating photosynthesis from chlorophyll and light data and for oceanographic surveys during which sampling of chlorophyll a is carried out throughout the 24-hr day.

scholarly journals Acute Effects of Morning Light on Plasma Glucose and Triglycerides in Healthy Men and Men with Type 2 Diabetes

2017 ◽  
Vol 32 (2) ◽  
pp. 130-142 ◽  
Author(s):  
Ruth I. Versteeg ◽  
Dirk J. Stenvers ◽  
Dana Visintainer ◽  
Andre Linnenbank ◽  
Michael W. Tanck ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Light Intensity ◽  
Plasma Glucose ◽  
Bright Light ◽  
Metabolic Effects ◽  
Ambient Light ◽  
Acute Effects ◽  
Postprandial Plasma Glucose ◽  
Glucose Levels

Ambient light intensity is signaled directly to hypothalamic areas that regulate energy metabolism. Observational studies have shown associations between ambient light intensity and plasma glucose and lipid levels, but human data on the acute metabolic effects of light are scarce. Since light is the main signal indicating the onset of the diurnal phase of physical activity and food intake in humans, we hypothesized that bright light would affect glucose and lipid metabolism. Therefore, we determined the acute effects of bright light on plasma glucose and lipid concentrations in 2 randomized crossover trials: (1) in 8 healthy lean men and (2) in 8 obese men with type 2 diabetes. From 0730 h, subjects were exposed to either bright light (4000 lux) or dim light (10 lux) for 5 h. After 1 h of light exposure, subjects consumed a 600-kcal mixed meal. Primary endpoints were fasting and postprandial plasma glucose levels. In healthy men, bright light did not affect fasting or postprandial plasma glucose levels. However, bright light increased fasting and postprandial plasma triglycerides. In men with type 2 diabetes, bright light increased fasting and postprandial glucose levels. In men with type 2 diabetes, bright light did not affect fasting triglyceride levels but increased postprandial triglyceride levels. We show that ambient light intensity acutely affects human plasma glucose and triglyceride levels. Our findings warrant further research into the consequences of the metabolic effects of light for the diagnosis and prevention of hyperglycemia and dyslipidemia.

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