scholarly journals Modification of Petunia seedling Carbohydrate Partitioning by Irradiance

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1073d-1073
Author(s):  
David F. Grarper ◽  
Will Healy
Keyword(s):  
Leaf Area ◽  
Oxygen Evolution ◽  
Petunia Hybrida ◽  
Soluble Sugars ◽  
Dry Weight ◽  
Invertase Activity ◽  
Photon Flux ◽  
Total Carbohydrate ◽  
Leaf Stage ◽  
Area Basis

Petunia × hybrida Villm. `Red Flash' plants were irradiated for either 10 or 20 mol day1 photosynthetic photon flux (PPF) in growth chambers using one of the following treatments: 175 μmol m-2 s-1 for 16 h, 350 μmol m-2 s-1 for 8 or 16 h or 350 μmol m-2 s-1 for 8 h plus 8 h incandescent day extension (5 μmol m-2 s-1 PPF). These four treatments were designed to examine the effects of increased peak and total daily integrated PPF as well as increased photosynthetic (Pn) period and photoperiod resulting from supplemental irradiance treatment of seedlings. Previous seedling petunia research indicated a greater response to supplemental lighting during expansion of the second true leaf. Therefore, seedlings were sampled for analysis at the two leaf stage and also later at the four leaf stage to examine effects at a later stage of growth.Increasing total integrated PPF increased total carbohydrate production, seedling dry weight, rate of seedling growth, and acid invertase activity once the seedlings reached the two leaf stage. Increasing total PPF resulted in greater partitioning into ethanol soluble sugars rather than starch at the two leaf stage. Increasing the photoperiod only, with an incandescent day extension treatment, reduced total carbohydrate production at the two leaf stage.Maximal oxygen evolution was observed when seedlings received 350 μmolm-2s-1 for 8 h when expressed on a leaf area or dry weight basis. The use of an 8 h day extension treatment to extend the photoperiod from 8 to 16 h resulted in the lowest rates of oxygen evolution on a leaf area basis.

scholarly journals Modification of Petunia Seedling Carbohydrate Partitioning by Irradiance

1992 ◽  
Vol 117 (3) ◽  
pp. 477-480
Author(s):  
David F. Graper ◽  
Will Healy
Keyword(s):  
Petunia Hybrida ◽  
Soluble Sugars ◽  
Dry Weight ◽  
Invertase Activity ◽  
Acid Invertase ◽  
Starch Accumulation ◽  
Photon Flux ◽  
Photosynthetic Photon Flux ◽  
Total Carbohydrate ◽  
Relative Growth

Petunia × hybrida Villm. `Red Flash' plants received either 10 or 20 mol·day-1 photosynthetic photon flux (PPF) in growth chambers at: 175 μmol·m-2·s-1 for 16 hours, 350 μmol·m-2·s-1 for 8 or 16 hours, or 350 μmol·m-2 s-1 for 8 hours plus 8 hours of incandescent photoperiod extension (5 μmol·m-2·s-1 PPF). The irradiation components of peak, total, and duration were examined. Doubling total PPF increased total carbohydrate (CHO) production by 60%, seedling dry weight (DW) by 30%, rate of seedling growth by 25%, and acid invertase activity by 50% compared to the other treatments, once the seedlings had reached the two-leaf stage. Seedlings receiving 20 mol·day-1 PPF partitioned 14% more CHO into ethanol soluble sugars rather than starch, which may explain the increase in relative growth rate observed with supplemental irradiance treatments. Extending the photoperiod for 8 hours with 5 μmol·m-2·s-1 PPF reduced total CHO production by 50% compared to the same treatment without photoperiodic lighting. Treatment with 350 μmol·m-2·s-1 for 8 hours resulted in the highest O2 evolution (8.8 μmol O2/min per dm2). Increasing the photoperiod from 8 to 16 hours gave the lowest rate of O2 evolution (4.5 μmol O2/min per dm2). Previous reports of the importance of photosynthetic period in controlling partitioning between starch and sugars may have simply observed a decreasing rate of starch accumulation due to increased total PPF.

scholarly journals PETUNIA SEEDLING GROWTH - HPS PHOTOPERIOD STUDY

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1103c-1103
Author(s):  
Will Healy ◽  
David Graper
Keyword(s):  
Soil Temperature ◽  
Leaf Area ◽  
Seedling Growth ◽  
Photosynthetic Rate ◽  
Dry Weight ◽  
Fresh Weight ◽  
Total Leaf Area ◽  
Leaf Stage ◽  
Exponential Increase ◽  
Area Basis

Petunia `Red Flash' seedling were grown under HPS (175 μmolm-2 s-1) photoperiod treatments of 10, 12, 14 or 16 hr at 20C soil temperature in a shaded glasshouse where the maximum peak PPF was reduced to 150 μmolm-2s-1. Seedling dry weight and individual leaf area were determined daily. The photosynthetic rate was determined when seedlings reached the second true leaf stage.The dry weight response to increasing photoperiod durations was cubic with a peak at 14 hr. Seedling dry weight increased slowly during days 5 through 10 then increased rapidly during the next 7 to 10 days. This increase coincided with the unfolding of leaves one through four. The total leaf area showed a cubic response to the photoperiod treatments. The leaf area increased slowly then began an exponential increase after day 10. The photosynthetic rate per gram dry weight was increased by the 10 hr photoperiod treatment when compared to the 16 hr treatment. The increased photosynthetic rate was not observed when the data was calculated on a fresh weight or leaf area basis.

Growth and development at cold-hardening temperatures. Pigment and benzoquinone accumulation in winter rye

1985 ◽  
Vol 63 (4) ◽  
pp. 716-721 ◽  
Author(s):  
Marianna Krol ◽  
Norman P. A. Huner
Keyword(s):  
Leaf Area ◽  
Fold Increase ◽  
Dry Weight ◽  
Cold Hardening ◽  
Carotenoid Content ◽  
Winter Rye ◽  
Warm Temperature ◽  
Leaf Ontogeny ◽  
Unit Leaf ◽  
Area Basis

Accumulation of chlorophyll, the carotenoids (β-carotene, lutein, violaxanthin, and neoxanthin), and the benzoquinones (plastoquinone A and α-tocopherol) were monitored in 'Puma' rye as a function of leaf ontogeny at warm and cold-hardening temperatures. Although the kinetics of accumulation differed among the leaves of warm-grown plants, the initial and maximum levels of the pigments and benzoquinones expressed on a leaf area basis did not differ significantly among the first four leaves of the main culm. In contrast, the third and fourth leaf of cold-grown plants, which developed completely at the low temperature, generally exhibited initial and maximum pigment and benzoquinone levels 60–300% greater than was observed for leaf 1 and 2 of cold-grown plants, which were completely or partially developed at the warm temperature regime. This resulted in pigment and benzoquinone levels which were 1.6- to 3-fold greater in the plants grown at cold-hardening temperatures than those grown at the warm temperature, when expressed on a per unit leaf area basis. However, when pigment accumulation was calculated on a chlorophyll basis, the benzoquinone content of leaves that developed solely at cold-hardening temperatures exhibited a 1.7-fold increase over the same leaves developed at warm temperatures. Carotenoids did not exhibit this trend. Calculations based on chlorophyll/carotenoid content and dry weight accumulation indicated that leaves that were developed at cold-hardening temperatures appeared to produce more dry matter per unit of photosynthetic pigments than the same leaves that were developed at nonhardening temperatures.

scholarly journals Acceleration of Begonia × semperflorens-cultorum Growth Using Supplemental Irradiance

HortScience ◽  
1991 ◽  
Vol 26 (3) ◽  
pp. 258-260
Author(s):  
Raymond Kessler ◽  
Allan M. Armitage ◽  
David S. Koranski
Keyword(s):  
Leaf Area ◽  
Plant Height ◽  
Exposure Time ◽  
Vegetative Growth ◽  
Dry Weight ◽  
Metal Halide ◽  
Leaf Stage ◽  
True Leaf ◽  
Begonia Semperflorens

Plug flats of Begonia × semperflorens-cultorum Hort. `Pizzazz Red', Vodka', and `Viva' were provided 0, 50, 125, or 200 μmol·s-1·m-2 metal-halide supplemental irradiance in the greenhouse for 0, 2, 4, 6, or 8 weeks. Treatments were initiated when seedlings were in the first true leaf stage (2 weeks after sowing). Plug-grown begonias reached transplantable dry weight and leaf area after 4 weeks of 125 μmol·s-1·m-2 supplemental exposure, while those under O and 50 μmol·s-1·m-2 required 6 to 8 weeks. Fewest number of days to visible bud and anthesis and the fewest number of nodes for all cultivars occurred after 2 weeks of 125 μmol·s-1·m-2 supplemental exposure. The same conditions achieved the greatest final leaf area and plant height; however, final dry weight was unaffected. Additional supplemental irradiance and/or exposure time did not accelerate flowering or improve vegetative growth of finished plants.

scholarly journals Leaf Attributes as Indices of Fruit Quality in Prune Tree Canopies

HortScience ◽  
1990 ◽  
Vol 25 (7) ◽  
pp. 751-754 ◽  
Author(s):  
S.M. Southwick ◽  
S.A. Weinbaum ◽  
T.T. Muraoka ◽  
W.R. Krueger ◽  
K.A. Shackel ◽  
...  
Keyword(s):  
Leaf Area ◽  
Fruit Quality ◽  
Fruit Size ◽  
Dry Weight ◽  
Tree Canopy ◽  
Photon Flux ◽  
Range Analysis ◽  
Unit Leaf ◽  
Tree Canopies ◽  
Leaf Dry Weight

Leaf dry weight per leaf area (LDW/LA); weight of leaf N per unit leaf area (LN/LA); leaf dry weight (LDW); and fruit quality, particularly sugar per fruit (SF); fruit fresh weight (FFW); and fruit dry weight (FDW) were measured over a range of daily average incident photosynthetic photon flux values (PPF) (50 to 1000 μmol·s-1·m-2) in 7-year-old prune (Prunus domestics L. syn. `Petite d'Agen') tree canopies. Linear or curvilinear relationships between these leaf attributes and fruit characteristics were significant over the PPF range. Analysis of LDW/LA or LN/LA may be used to indicate tree canopy locations in which fruit size and quality is limited by suboptimal PPF.

scholarly journals Temperature Effects on Growth of Impatiens Plug Seedlings in Controlled Environments

1992 ◽  
Vol 117 (2) ◽  
pp. 209-215 ◽  
Author(s):  
David R. Dreesen ◽  
Robert W. Langhans
Keyword(s):  
Leaf Area ◽  
Growth Period ◽  
Dry Weight ◽  
Photon Flux ◽  
Initial Growth ◽  
Growth Responses ◽  
Shoot Height ◽  
Seedling Age ◽  
Shoot Dry Weight ◽  
Air Temperatures

The objective of this study was to determine the dry weight, height, and leaf area growth responses of impatiens (Impatiens walerana Hook. f.) plug seedlings to air temperatures ranging from 18 to 29C. The conditions maintained in the controlled-environment growth rooms (CEGR) were ambient C02 levels, 24-h lighting, and photosynthetic photon flux (PPF) ranging from ≈215; to 335 μmol·m-2·s-1. Mean daily temperatures of the plug medium ranged from 19.6 to 27.7C. At the higher PPF level, shoot dry weight decreased at plug medium temperatures (PMT) > 25C; at lower PPF levels (<300 μmol·m-2·s-1), shoot dry weight continued to increase with PMT > 25C. The mean relative growth rate (MRGR) of shoot dry weight was positively correlated with PMT during the initial growth period (up to 14 days from sowing) and was negatively correlated thereafter. The maximum MRGR was predicted to occur at 11.7 days from sowing for a PMT of 19.6C, at 10.8 days for a PMT of 21.6C, and at 9.7 days for a PMT of 23.6C. Linear regression coefficients of shoot height as a function of PMT were substantially higher for seedlings grown at lower PPF than those for seedlings from the highest PPF level. Seedling leaf area consistently increased with increasing temperature. Net assimilation rate (NAR) decreased with increasing seedling age NAR increased with increasing PPF. A decrease in NAR was apparent at 29C relative to values at the lower temperatures. Leaf area ratio (LAR) declined with increasing seedling age and PPF; a quadratic relationship of LAR as a function of PMT indicates a minimum LAR at 22.5C. The seedlings grown at 29C were excessively tall, had thin succulent leaves, and were judged unacceptable for shipping and transplanting. Maximum quality indices (i.e., dry weight per height) were found at PMT of 24.3 to 25.OC for 10- to 14-day-old seedlings and at PMT of 23.0 to 24.OC for 16- to 20-day-old seedlings.

scholarly journals CO2 enrichment and increasing light intensity till a threshold level, enhance growth and water use efficiency of lettuce plants in controlled environment

2020 ◽  
Vol 48 (4) ◽  
pp. 2244-2262
Author(s):  
Maryam ESMAILI ◽  
Sasan ALINIAEIFARD ◽  
Mahmoud MASHAL ◽  
Parisa GHORBANZADEH ◽  
Mehdi SEIF ◽  
...  
Keyword(s):  
Light Intensity ◽  
Water Use Efficiency ◽  
Leaf Area ◽  
Water Use ◽  
Dry Weight ◽  
Co2 Concentration ◽  
Photon Flux ◽  
Fresh Weight ◽  
Co2 Concentrations ◽  
Use Efficiency

Carbon dioxide (CO2) and light intensity are the two main environmental drivers known to play important roles in crop growth and yield. In the current study, lettuce seedlings were exposed to four different light intensities [(75, 150, 300 and 600 Photosynthetic Photon Flux Density (PPFD)] and four different concentrations of CO2 (400, 800, 1200 and 1600 ppm). By increasing light intensity and CO2 concentration growth parameters such as fresh weight, dry weight and leaf area were stepwise increased from 75 to 300 PPFD and from 400 ppm to 1200 ppm CO2 concentration. Maximum fresh weight was observed in 300 PPFD under both 1200 ppm and 1600 ppm CO2 concentrations. Highest dry weight was obtained in plants exposed to 300 and 600 PPFD under both 1200 and 1600 ppm CO2 concentrations. Highest leaf area was detected in 300 PPFD under both 1200 and 1600 ppm CO2 concentrations. Widest stomatal pore aperture was detected in 600 PPFD under 400 ppm and 800 ppm CO2 concentrations. Evapotranspiration increased in a light intensity and CO2 concentration-dependent manner; higher light intensity or higher CO2 concentration, more evapotranspiration. Highest water use efficiency (WUE) was achieved in plants exposed to 300 PPFD under 1200 ppm CO2 concentration. In conclusion, to achieve best growth performance and WUE, lettuce should be produced under 300 PPFD light intensity and 1200 ppm CO2.

Effect of Light, Watering Frequency, and Chlorsulfuron on Canada Thistle (Cirsium arvense)

Weed Science ◽  
1991 ◽  
Vol 39 (4) ◽  
pp. 590-594 ◽  
Author(s):  
Robert L. Zimdahl ◽  
Jingzhu Lin ◽  
Armando A. Dall'Armellina
Keyword(s):  
Leaf Area ◽  
Field Experiments ◽  
Dry Weight ◽  
Photosynthetic Photon Flux Density ◽  
Water Levels ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Canada Thistle ◽  
Root Dry Weight ◽  
Effect Of Light

Greenhouse and field experiments were conducted to determine effects of light, water, and chlorsulfuron on growth of Canada thistle. In the greenhouse, shoot and root dry weight, leaf area, and number of inflorescences decreased as light and water levels decreased. In the field, shoot and root dry weight, leaf area, and number of Canada thistle inflorescences were positively correlated with light intensity from 1832 to 30 μmol m−2s−1photosynthetic photon flux density (PPFD). The greatest effect of light was on inflorescence production which was eliminated at 30 μmol m−2s−1(PPFD). The combined effect of water stress and chlorsulfuron decreased root and shoot growth but did not eliminate it.

scholarly journals Evaluation of Jatropha curcas L. leaves mulching on wheat growth and biochemical attributes under water stress

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Muhammad Irshad ◽  
Faizan Ullah ◽  
Shah Fahad ◽  
Sultan Mehmood ◽  
Asif Ullah Khan ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Water Stress ◽  
Adverse Effects ◽  
Leaf Area ◽  
Plant Height ◽  
Field Experiments ◽  
Soluble Sugar ◽  
Soluble Sugars ◽  
Dry Weight ◽  
Carotenoid Content

Abstract Background Organic mulches are widely used in crop production systems. Due to their benefits in improving soil fertility, retention of soil moisture and weed control. Field experiments were conducted during wheat growing seasons of 2018–2019 and 2019–2020 to evaluate the effects of Jatropha leaves mulch on the growth of wheat varieties ‘Wadan-17’ (rainfed) and ‘Pirsabaq-2013’ (irrigated) under well irrigated and water stress conditions (non-irrigated maintaining 40% soil field capacity). Jatropha mulch was applied to the soil surface at 0, 1, 3 and 5 Mg ha−1 before sowing grains in the field. Under conditions of water stress, Jatropha mulch significantly maintained the soil moisture content necessary for normal plant growth. Results We noted a decrease in plant height, shoot and root fresh/dry weight, leaf area, leaf relative water content (LRWC), chlorophyll, and carotenoid content due to water stress. However, water stress caused an increase in leaf and root phenolics content, leaf soluble sugars and electrolytes leakage. We observed that Jatropha mulch maintained LRWC, plant height, shoot and root fresh/dry weight, leaf area and chlorophyll content under water stress. Moreover, water stress adverse effects on leaf soluble sugar content and electrolyte leakage were reversed to normal by Jatropha mulch. Conclusion Therefore, it may be concluded that Jatropha leaves mulch will minimize water stress adverse effects on wheat by maintaining soil moisture and plant water status.

scholarly journals Spectral Effects of Supplemental Greenhouse Radiation on Growth and Flowering of Annual Bedding Plants and Vegetable Transplants

HortScience ◽  
2017 ◽  
Vol 52 (9) ◽  
pp. 1221-1228 ◽  
Author(s):  
Brian R. Poel ◽  
Erik S. Runkle
Keyword(s):  
Leaf Area ◽  
Plant Morphology ◽  
Dry Weight ◽  
The Other ◽  
Radiation Absorption ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Radiation Quality ◽  
White Leds ◽  
Bedding Plants

Supplemental radiation (SR), traditionally provided by high-pressure sodium (HPS) lamps, is recommended for greenhouse production of seedlings during radiation-limiting conditions. Light-emitting diodes (LEDs) have emerged as an appealing alternative to HPS lamps primarily because they can provide SR at improved energy efficiencies, they have longer fixture lifetimes, and the radiation spectrum can be tailored to potentially manipulate plant morphology by targeting radiation absorption of specific photoreceptors. We grew seedlings of three annual bedding plants and two vegetable transplants in greenhouses at 20 °C under a 16-h photoperiod under six SR treatments: five that delivered a photosynthetic photon flux density (PPFD) of 90 μmol·m−2·s–1 from HPS lamps (HPS90) or LEDs [four treatments composed of blue (B; 400–500 nm), red (R; 600–700 nm), far red (FR; 700–800 nm), and/or white LEDs] and one that delivered 10 μmol·m−2·s–1 from HPS (HPS10) lamps as a control with matching photoperiod. The LED treatments, defined by the percentages of B, green (G; 500–600 nm), and R radiation, were B10R90, B45R55, B10G5R85, and B12G20R68 + FR (FR at 12 μmol·m−2·s–1). At transplant, leaf area and seedling height were similar among 90 μmol·m−2·s–1 treatments in all species except snapdragon (Antirrhinum majus), in which seedlings grown under B12G20R68 + FR had 62% greater leaf area than those grown under B45R55 and were 47%, 18%, 38%, and 62% taller than those grown under HPS90, B10R90, B10G5R85, and B45R55, respectively. After transplant and finishing under the same SR treatments, snapdragon flowered on average 7 days earlier under the B12G20R68 + FR treatment than the other LED treatments, whereas geranium (Pelargonium ×hortorum) grown under B45R55 and B12G20R68 + FR flowered 7 to 9 days earlier than those under the B10G5R85 and B10R90 treatments. Seedlings of each species grown under the HPS10 treatment accumulated less dry weight and took longer to flower compared with seedlings under the other SR treatments. We conclude that radiation quality of SR has relatively little effect on seedling growth and subsequent flowering although in some crops, flowering may be earlier when SR includes FR radiation.

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