scholarly journals Fenologia e trocas gasosas da videira cv. Sweet Sunshine em clima semiárido

2016 ◽  
Vol 7 (3) ◽  
pp. 319 ◽  
Author(s):  
Essione Ribeiro Souza ◽  
Amanda Cristina Esteves Amaro ◽  
Laíse De Sousa Santos ◽  
Elizabeth Orika Ono ◽  
João Domingos Rodrigues
Keyword(s):  
Gas Exchange ◽  
Titratable Acidity ◽  
Dry Weight ◽  
Co2 Assimilation ◽  
Photosynthetic Photon Flux Density ◽  
Soluble Solids ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Fresh Weight ◽  
Semi Arid Region

Several physiological and environmental factors can influence the development and growth of vines cultivated in irrigated areas of the Brazilian semi-arid region. Therefore, it is necessary to characterize the phenology of ‘Sweet Sunshine’ grapevine under Sub-medium São Francisco Valley, Brazil conditions in order to set up the managements employed for the crop. To characterize the phenology 12 plants were selected, distributed in four repetitions, from the first growing season, both in the 2nd half of 2012 as in the 1st half of 2013. The observations of plant development phases were initiated immediately after pruning, ending at the harvest. Gas exchange measures as net CO2 assimilation rate, stomatal conductance, transpiration rate, intercellular CO2 concentrations, water use efficiency, apparent carboxylation efficiency (Rubisco) and the photosynthetic photon flux density were performed at inflorescence, early flowering, growth and softening of berries phases. The productive characterization was performed weekly, determining the clusters fresh weight length; fresh weight, diameter, length and volume of the berries; soluble solids content and titratable acidity; fresh and dry weight, basal, median and apical diameter of the stems. It was found that physiological parameters induced changes in the characteristics of the plants for the two evaluated periods, since the behavior of the curve for gas exchange measurements were distinct, exhibiting productive and commercial potential.

scholarly journals Gas exchange in gariroba palms grown under subtropical conditions

2018 ◽  
Vol 36 (2) ◽  
pp. 211-216
Author(s):  
Valéria A Modolo ◽  
Norma M Erismann ◽  
Maria LS Tucci
Keyword(s):  
Gas Exchange ◽  
Early Morning ◽  
Co2 Assimilation ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Net Co2 Assimilation ◽  
Winter Temperatures ◽  
Net Assimilation ◽  
Autumn And Winter

ABSTRACT Gariroba palm, native to Brazil, produces bitter heart-of-palm, consumed as vegetable in salads, as well as in other Brazilian recipes. This research was carried out in field condition to evaluate diurnal and seasonal variation of gas exchange of gariroba palms cultivated under subtropical conditions, considering their interrelation with some climate elements. Plants were evaluated within two consecutive years, grown under field conditions and irrigated, spaced 2x1 m. Net assimilation of CO2 (PN), stomatal conductance (g s ), transpiration (E), leaf temperature (T l ) within the chamber and the photosynthetic photon flux density (PPFD) were evaluated. Water use efficiency (WUE) was estimated by the ratio: WUE = PN/E. Net CO2 assimilation (PN), showed a plateau in May, observed from 9:30 to 14 h, reaching an average of 5.4 μmol m-2s-1, then declining toward late afternoon. As far as August is concerned, PN increased from the early morning until 11 h, reaching the maximum value of 9.0 µmol m-2s-1. From then on it decreased reaching 6.0 µmol m-2s-1 at 14 h. Gariroba palms cultivated and even under lower autumn and winter temperatures presented gas exchange characteristics consistent to climatic elements.

scholarly journals Sunlight transmitted by colored shade nets on photosynthesis and yield of cucumber

2018 ◽  
Vol 48 (9) ◽  
Author(s):  
Felipe Ayala Tafoya ◽  
Moisés Gilberto Yáñez Juárez ◽  
Carlos Alfonso López Orona ◽  
Raymundo Medina López ◽  
Teresa de Jesús Velázquez Alcaraz ◽  
...  
Keyword(s):  
Block Design ◽  
Red Light ◽  
Dry Weight ◽  
Co2 Assimilation ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Protected Cultivation ◽  
Photosynthetic Responses ◽  
Photosynthetic Properties

ABSTRACT: Black shading nets are widely used in the protected cultivation of vegetables as a technique for controlling light and temperature, while the colored shading nets, with special optical properties to improve the use of solar radiation, appeared recently in the agricultural plastics market. Light quality transmitted by gray, aluminized, pearl, blue, red and black (control) nets with 30% shade was evaluated, as well as its effects on photosynthetic properties and fruits production of cucumber plants. Treatments (shade nets) were established under a randomized complete block design with four repetitions. The red net transmitted 23.7 and 40.3% more photosynthetic photon flux density (400 to 700nm) and red light (600 to 700nm) and the blue net transmitted 36% more blue light (400 to 500nm) in comparison with the respective transmissions of black net. All nets increased the photosynthetic responses: transpiration, stomatal conductance and CO2 assimilation, observed in plants grown under black net. Leaf greenness (41.6 SPAD units) and foliar area (90dm2) increased 22.8 and 38.9% with the red net, while the dry weight of leaf (52.5g) increased 21.9% with pearl net. Pearl, red, aluminized and blue nets showed to be viable alternatives because the production of fruit increased in 71, 48, 46 and 46%, respectively, in comparison with the conventional black net (52t ha-1).

The value of red light at night for increasing basil yield

2018 ◽  
Vol 98 (6) ◽  
pp. 1321-1330
Author(s):  
Jaimin S. Patel ◽  
Leora Radetsky ◽  
Mark S. Rea
Keyword(s):  
Plant Height ◽  
Red Light ◽  
Leaf Size ◽  
Cost Effective ◽  
Dry Weight ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Light At Night ◽  
Sweet Basil

Sweet basil (Ocimum basilicum L.) is primarily used for culinary purposes, but it is also used in the fragrance and medicinal industries. In the last few years, global sweet basil production has been significantly impacted by downy mildew caused by Peronospora belbahrii Thines. Nighttime exposure to red light has been shown to inhibit sporulation of P. belbahrii. The objective of this study was to determine if nighttime exposure to red light from light-emitting diodes (λmax = 625 nm) could increase plant growth (plant height and leaf size) and yield (number and weight of leaves) in basil plants. In two sets of greenhouse experiments, red light was applied at a photosynthetic photon flux density of 60 μmol m−2 s−1 during the otherwise dark night for 10 h (from 2000 to 0600). The results demonstrate that exposure to red light at night can increase the number of basil leaves per plant, plant height, leaf size (length and width), and leaf fresh and dry weight compared with plants in darkness at night. The addition of incremental red light at night has the potential to be cost-effective for fresh organic basil production in controlled environments.

scholarly journals Optimal LED Wavelength Composition for the Production of High-Quality Watermelon and Interspecific Squash Seedlings Used for Grafting

Agronomy ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 870 ◽  
Author(s):  
Filippos Bantis ◽  
Athanasios Koukounaras ◽  
Anastasios S. Siomos ◽  
Kalliopi Radoglou ◽  
Christodoulos Dangitsis
Keyword(s):  
Blue Emission ◽  
Dry Weight ◽  
Photosynthetic Photon Flux Density ◽  
Stem Diameter ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Light Sources ◽  
High Quality ◽  
Light Emitting ◽  
Shoot Dry Weight

Watermelon is cultivated worldwide and is mainly grafted onto interspecific squash rootstocks. Light-emitting diodes (LEDs) can be implemented as light sources during indoor production of both species and their spectral quality is of great importance. The objective of the present study was to determine the optimal emission of LEDs with wide wavelength for the production of watermelon and interspecific squash seedlings in a growth chamber. Conditions were set at 22/20 °C temperature (day/night), 16 h photoperiod, and 85 ± 5 μmol m−2 s−1 photosynthetic photon flux density. Illumination was provided by fluorescent (FL, T0) lamps or four LEDs (T1, T2, T3, and T4) emitting varying wide spectra. Watermelon seedlings had greater shoot length, stem diameter, cotyledon area, shoot dry weight-to-length (DW/L) ratio, and Dickson’s quality index (DQI) under T1 and T3, while leaf area and shoot dry weight (DW) had higher values under T1. Interspecific squash seedlings had greater stem diameter, and shoot and root DW under T1 and T3, while leaf and cotyledon areas were favored under T1. In both species, T0 showed inferior development. It could be concluded that a light source with high red emission, relatively low blue emission, and a red:far-red ratio of about 3 units seems ideal for the production of high-quality watermelon (scion) and interspecific squash (rootstock) seedlings.

Effects of CO2 enrichment on growth of Liquidambarstyraciflua and Pinustaeda seedlings under different irradiance levels

1984 ◽  
Vol 14 (3) ◽  
pp. 343-350 ◽  
Author(s):  
Leslie C. Tolley ◽  
B. R. Strain
Keyword(s):  
Loblolly Pine ◽  
Atmospheric Carbon Dioxide ◽  
Co2 Enrichment ◽  
Dry Weight ◽  
Photosynthetic Photon Flux Density ◽  
High Irradiance ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Dry Matter Accumulation ◽  
Pine Seedlings

Mathematical growth analysis techniques were used to assess the effects of atmospheric carbon dioxide enrichment on growth and biomass partitioning of Liquidambarstyraciflua L. (sweetgum) and Pinustaeda L. (loblolly pine) seedlings. Plants were grown from seed under high (1000 μmol•m−2•s−1) and low (250 μmol•m−2•s−1) photosynthetic photon flux density at CO2 concentrations of 350, 675, and 1000 μL•L−1 for 84 or 112–113 days. Elevated atmospheric CO2 concentration significantly increased height, leaf area, basal stem diameter, and total dry weight of sweetgum seedlings grown under high irradiance and to a lesser extent under low irradiance. Increases in dry matter accumulation were associated with early CO2 enhancement of net assimilation rate, but increases in amount of leaf surface area contributed more towards maintenance of larger size as seedlings aged. For sweetgum seedlings in particular, reduction of growth by low irradiance under normal atmospheric CO2 was compensated for by growing plants with elevated CO2. In contrast, elevated CO2 concentration produced no significant increase in growth of loblolly pine seedlings.

scholarly journals Light Environment and Time of Harvest Affect `Delicious' Apple Fruit Quality Characteristics

1992 ◽  
Vol 117 (4) ◽  
pp. 551-557 ◽  
Author(s):  
Richard J. Campbell ◽  
Richard P. Marini
Keyword(s):  
Photosynthetic Photon Flux Density ◽  
Apple Fruit ◽  
Fruit Weight ◽  
Soluble Solids ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Photon Density ◽  
Fruit Characteristics ◽  
Solids Concentration ◽  
Harvest Dates

Photosynthetic photon flux density (PPFD), measured at various canopy positions throughout the growing season in 1989 and 1990, was used to explain variation in fruit characteristics of `Delicious' apples (Malus domestica Borkh.) harvested from these positions at 135, 145, 155, and 165 days after full bloom (DAFB). Hours above an average PPFD threshold of 250 μmol·m-2·s-1 (HR250) explained an average of only 2% more variation in fruit characteristics than other PPFD threshold levels or total cumulative photosynthetic photon density (PPD) in each year. Percent of red surface had a positive linear relationship with HR250 on all harvest dates in both years; intercepts increased on each successive harvest. The slopes and R2 were highest at 135 DAFB and decreased on each successive harvest. Intensity of red pigmentation and soluble solids concentration also increased linearly with HR250, with equivalent slopes and increasing intercepts on each successive harvest. Fruit weight, flesh firmness, length: diameter ratio, and starch index were not consistently affected by any measure of canopy light levels. Except for intensity of redness, relationships developed between fruit characteristics and cumulative late-season PPD during the final 10 weeks before harvest (CPPDLS) had trends similar to the models for HR250 for all harvests in both years. Models developed with instantaneous light measurements were similar to those developed with the more detailed cumulative light measurements.

scholarly journals Interaction of Light Intensity and CO2 Concentration Alters Biomass Partitioning in Chrysanthemum

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Maral Hosseinzadeh ◽  
Sasan Aliniaeifard ◽  
Aida Shomali ◽  
Fardad Didaran
Keyword(s):  
Light Intensity ◽  
Growth Management ◽  
Growth Yield ◽  
Dry Weight ◽  
Co2 Concentration ◽  
Photosynthetic Photon Flux Density ◽  
Biomass Partitioning ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Vegetative Organs

Abstract Biomass partitioning is one of the pivotal determinants of crop growth management, which is influenced by environmental cues. Light and CO2 are the main drivers of photosynthesis and biomass production in plants. In this study, the effects of CO2 levels: ambient 400 ppm (a[CO2]) and elevated to 1,000 ppm (e[CO2]) and different light intensities (75, 150, 300, 600 μmol·m−2·s−1 photosynthetic photon flux density – PPFD) were studied on the growth, yield, and biomass partitioning in chrysanthemum plants. The plants grown at higher light intensity had a higher dry weight (DW) of both the vegetative and floral organs. e[CO2] diminished the stimulating effect of more intensive light on the DW of vegetative organs, although it positively influenced inflorescence DW. The flowering time in plants grown at e[CO2] and light intensity of 600 μmol·m−2·s−1 occurred earlier than that of plants grown at a[CO2]. An increase in light intensity induced the allocation of biomass to inflorescence and e[CO2] enhanced the increasing effect of light on the partitioning of biomass toward the inflorescence. In both CO2 concentrations, the highest specific leaf area (SLA) was detected under the lowest light intensity, especially in plants grown at e[CO2]. In conclusion, elevated light intensity and CO2 direct the biomass toward inflorescence in chrysanthemum plants.

scholarly journals Supplementary LED Interlighting Improves Yield and Precocity of Greenhouse Tomatoes in the Mediterranean

Agronomy ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1002 ◽  
Author(s):  
Ivan Paucek ◽  
Giuseppina Pennisi ◽  
Alessandro Pistillo ◽  
Elisa Appolloni ◽  
Andrea Crepaldi ◽  
...  
Keyword(s):  
Growth Yield ◽  
Photosynthetic Photon Flux Density ◽  
Fruit Weight ◽  
Soluble Solids ◽  
Control Treatment ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Vegetative Development ◽  
Greenhouse Production ◽  
The Mediterranean

In Northern Europe, the use of light–emitting diodes (LEDs) is widely adopted in protected horticulture, enabling to enhance plant growth by ensuring needed radiative fluxes throughout seasons. Contrarily, the use of artificial lighting in Mediterranean greenhouse still finds limited applications. In this study, the effects of supplemental LED interlighting on vegetative development, fruit growth, yield, and fruit quality of high-wire tomato plants (Solanum lycopersicum L. cv. ‘Siranzo’) during spring and summer season were addressed in a hydroponic greenhouse in Italy. Plants were either grown under natural solar radiation (control), or by adding supplemental LED interlighting. LED treatment featured red (R) and blue (B) light (RB ratio of 3) and a photosynthetic photon flux density of 170 µmol m−2 s−1 for 16 h d−1. Supplemental LED interlighting enhanced yield as a result of increased fruit weight and dimension. While no effects on soluble solids content and fruit color at harvesting were observed, supplemental LED interlighting accelerated ripening by one week in spring and two weeks in summer and this also resulted in increased cumulated productivity (+16%) as compared to control treatment. Overall, supplemental LED interlighting can represent a feasible technology for tomato greenhouse production also in the Mediterranean region.

scholarly journals Photosynthetic responses of young cashew plants to varying environmental conditions

2005 ◽  
Vol 40 (8) ◽  
pp. 735-744 ◽  
Author(s):  
Rogéria Pereira de Souza ◽  
Rafael Vasconcelos Ribeiro ◽  
Eduardo Caruso Machado ◽  
Ricardo Ferraz de Oliveira ◽  
Joaquim Albenísio Gomes da Silveira
Keyword(s):  
Gas Exchange ◽  
Intercellular Co2 Concentration ◽  
Co2 Concentration ◽  
Co2 Assimilation ◽  
Photon Flux ◽  
Photochemical Quenching ◽  
Photon Flux Density ◽  
Effective Quantum Yield ◽  
Water Losses ◽  
Controlled Conditions

The aim of this study was to characterize gas exchange responses of young cashew plants to varying photosynthetic photon flux density (PPFD), temperature, vapor-pressure deficit (VPD), and intercellular CO2 concentration (Ci), under controlled conditions. Daily courses of gas exchange and chlorophyll a fluorescence parameters were measured under natural conditions. Maximum CO2 assimilation rates, under optimal controlled conditions, were about 13 mmol m-2 s-1 , with light saturation around 1,000 mmol m-2 s-1. Leaf temperatures between 25ºC and 35ºC were optimal for photosynthesis. Stomata showed sensitivity to CO2, and a closing response with increasing Ci. Increasing VPD had a small effect on CO2 assimilation rates, with a small decrease above 2.5 kPa. Stomata, however, were strongly affected by VPD, exhibiting gradual closure above 1.5 kPa. The reduced stomatal conductances at high VPD were efficient in restricting water losses by transpiration, demonstrating the species adaptability to dry environments. Under natural irradiance, CO2 assimilation rates were saturated in early morning, following thereafter the PPFD changes. Transient Fv/Fm decreases were registered around 11h, indicating the occurrence of photoinhibition. Decreases of excitation capture efficiency, decreases of effective quantum yield of photosystem II, and increases in non-photochemical quenching were consistent with the occurrence of photoprotection under excessive irradiance levels.

scholarly journals Red and Blue Netting Alters Leaf Morphological and Physiological Characteristics in Apple Trees

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 127
Author(s):  
Richard M. Bastías ◽  
Pasquale Losciale ◽  
Camilla Chieco ◽  
Luca Corelli-Grappadelli
Keyword(s):  
Gas Exchange ◽  
Leaf Gas Exchange ◽  
Red Light ◽  
Net Photosynthesis ◽  
Fruit Trees ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Apple Trees ◽  
Intrinsic Water Use Efficiency

There is little information about the role of red and blue light on leaf morphology and physiology in fruit trees, and more studies have been developed in herbaceous plants grown under controlled light conditions. The objective of this research was to evaluate the effect of red and blue screens on morpho-anatomy and gas exchange in apple leaves grown under ambient sunlight conditions. Apple trees cv. Fuji were covered by 40% red and blue nets, leaving trees with 20% white net as control. Light relations (photosynthetic photon flux density, PPFD; red to far-red light ratio, R/FR and blue to red light ratio, B/R), morpho-anatomical features of the leaf (palisade to spongy mesophyll ratio, P/S, and stomata density, SD) and leaf gas exchange (net photosynthesis rate, An; stomatal conductance, gs; transpiration rate, E; and intrinsic water use efficiency, IWUE) were evaluated. Red and blue nets reduced 27% PPFD, reducing by 20% SD and 25% P/S compared to control, but without negative effects on An and gs. Blue net increased gs 21%, leading to the highest E and lowest IWUE by increment of B/R light proportion. These findings demonstrate the potential use of red and blue nets for differential modulation of apple leaf gas exchange through sunlight management under field conditions.

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