Different Light Radiation Intensities on Cotton: A Physiological Approach

2019 ◽  
pp. 1-8
Author(s):  
Lucas Aparecido Manzani Lisboa ◽  
Fernando Takayuki Nakayama ◽  
Edivaldo Cia ◽  
Paulo Alexandre Monteiro de Figueiredo ◽  
Sérgio Bispo Ramos ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Block Design ◽  
Co2 Concentration ◽  
Co2 Assimilation ◽  
Luminous Intensity ◽  
Artificial Light ◽  
Light Intensities ◽  
Leaf Transpiration ◽  
Randomized Complete Block Design ◽  
Physiological Approach

The luminosity and the temperature are factors that act directly in the photosynthetic process, where an elevation of the luminous intensity can cause a reduction of the assimilation of carbon, which consequently lowers the development of the cotton. The objective of this work was to assess the response of physiological parameters of cotton when subjected to different artificial light intensities. Two varieties of cotton IMA5801B2RF and IACRDN, were interacting with five artificial light intensities: 0 (control); 500; 1000; 1500 and 2000 μmol m−2 s−1 of photosynthetically active radiation provided by LED bulbs. The experiment was set in a randomized complete block design using a 2x5 factorial scheme. The variables measured were the rate of CO2 assimilation, transpiration, stomatal conductance, inner CO2 concentration in the substomatic chamber, and efficient use of water (for which a portable device of gas exchange was used). The cotton varieties responded positively to different luminous intensities until reaching the point of maximum saturation between 1400 and 1600 µmol m-1 s-1 of light, which provided a better rate of CO2 assimilation, concentration of CO2 in the substomatic chamber, and efficient use of water. Leaf transpiration and stomatal conductance showed a positive linear response with increasing light intensity. The ideal luminous intensity for the use of Infra-Red Gas Analyzer - IRGA was 1500 µmol m-1 s-1 for the tested cotton varieties.

scholarly journals Photosynthesis of Physalis peruviana under different densities of photons and saline stress

2021 ◽  
Vol 37 ◽  
pp. e37082
Author(s):  
Francisco Romário Andrade Figueiredo ◽  
João Everthon da Silva Ribeiro ◽  
Jackson Silva Nóbrega ◽  
Wilma Freitas Celedônio ◽  
Reynaldo Teodoro de Fátima ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Abiotic Factors ◽  
Block Design ◽  
Co2 Concentration ◽  
Co2 Assimilation ◽  
Saline Stress ◽  
Physalis Peruviana ◽  
Randomized Block Design ◽  
Liquid Co2 ◽  
Internal Co2

Physalis peruviana L. is a solanacea that has been gaining prominence due to its fruits presenting good acceptance in the national and international market. However, several abiotic factors, such as salinity, can cause physiological disturbances in plants, and these changes may be of greater or lesser intent according to species. Therefore, the objective of the present work was to evaluate the physiological behavior of P. peruviana submitted to different fluxes of photosynthetically active photons (PPFD) and saline stress. The experimental design was a randomized block design with three saline levels (ECw) (0.5, 2.75 and 5.00 dS m-1) with four replications. Gas exchange measurements were performed with a portable infrared gas analyzer. Liquid CO2 assimilation, stomatal conductance, internal CO2 concentration, water use efficiency and instantaneous carboxylation efficiency were measured. Data were subjected to analysis of variance by F test and in cases of significance applied to regression analysis. The increase in PPFD provided reductions in stomatal conductance up to the density of approximately 400 μmol m-2s-1, being more pronounced in ECw of 2.75 and 5.0 dS m-1. The maximum CO2 assimilation rates in the three salinities are different according to the PPFD. The salinity of irrigation water reduced the quantum efficiency of photosynthesis in P. peruviana plants.

scholarly journals Physiological Parameters of Soybean Under Different Intensities of Artificial Light

2019 ◽  
Vol 11 (8) ◽  
pp. 188
Author(s):  
Lucas Aparecido Manzani Lisboa ◽  
Amanda Stelutti ◽  
Karla Caroline Santana Lima ◽  
Guilherme Bandeca Rafachinho ◽  
Renata Alari Chedid ◽  
...  
Keyword(s):  
Light Intensity ◽  
Co2 Concentration ◽  
Co2 Assimilation ◽  
Physiological Parameters ◽  
Artificial Light ◽  
Gas Analyzer ◽  
Infra Red ◽  
Glycine Max L ◽  
Use Efficiency ◽  
The Ideal

Luminosity and temperature are factors that directly act in photosynthetic process, in which the elevation of the light intensity may provoke reduction in the assimilation of carbon, impairing the development of the soybean culture. This work aimed to know physiological parameters of soybean (Glycine max L. Merr.) under different intensities of artificial light. The experiment was carried out in randomized blocks, in a factorial scheme 2 × 5, being two soybean cultivars (Potência and NS6700) and five densities of light: 0 (control), 500, 1000, 1500 and 2000 μmol m-2 s-1 of photosynthetically active radiation (PAR) provided by LED bulbs, with 4 repetitions, in total of 40 plots. The following variables were set: rate of CO2 assimilation (A), transpiration (E), stomatal conductance (gs), inner CO2 concentration in the substomatic chamber (Ci) and water use efficiency (WUE) in which a portable device of gas exchange was used (Infra-Red Gas Analyzer-IRGA, marca ADC BioScientific Ltd, modelo LC-Pro). Seedlings of soybean positively responded under different intensities of artificial light till reach the maximum saturation point between 1400 and 1600 µmol m-1 s-1 of light, which promoted a better rate of A, Ci andWUE. E and gs presented positive linear responses by increasing the intensity of artificial light. The ideal light intensity to the use of Infra-Red Gas Analyzer-IRGA between 1400 and 1600 µmol m-1 s-1 to the soybean culture.

Stomatal aperture can compensate altered stomatal density in Arabidopsis thaliana at growth light conditions

2006 ◽  
Vol 33 (11) ◽  
pp. 1037 ◽  
Author(s):  
Dirk Büssis ◽  
Uritza von Groll ◽  
Joachim Fisahn ◽  
Thomas Altmann
Keyword(s):  
Arabidopsis Thaliana ◽  
Stomatal Conductance ◽  
Stomatal Density ◽  
Co2 Assimilation ◽  
High Light ◽  
Stomatal Aperture ◽  
Photochemical Quenching ◽  
Light Conditions ◽  
Wild Type ◽  
Light Intensities

Stomatal density of transgenic Arabidopsis thaliana plants over-expressing the SDD1 (stomatal density and distribution) gene was reduced to 40% and in the sdd1-1 mutant increased to 300% of the wild type. CO2 assimilation rate and stomatal conductance of over-expressers and the sdd1-1 mutant were unchanged compared with wild types when measured under the light conditions the plants were exposed to during growth. Lower stomatal density was compensated for by increased stomatal aperture and conversely, increased stomatal density was compensated for by reduced stomatal aperture. At high light intensities the assimilation rates and stomatal conductance of SDD1 over-expressers were reduced to 80% of those in wild type plants. Areas beneath stomata and patches lacking stomata were analysed separately. In areas without stomata, maximum fluorescence yield (Fv / Fm) and quantum yield of photosystem II (Φ PSII) were significantly lower than in areas beneath stomata. In areas beneath stomata, Fv / Fm and Φ PSII were identical to levels measured in wild type leaves. At high light intensities over-expressers showed decreased photochemical quenching (qP) compared with wild types. However, the decrease of qP was significantly stronger in areas without stomata than in mesophyll areas beneath stomata. At high CO2 partial pressures and high light intensities CO2 assimilation rates of SDD1 over-expressers did not reach wild type levels. These results indicate that photosynthesis in SDD1 over-expressers was reduced because of limiting CO2 in areas furthest from stomata at high light.

The interplay between irrigation and fruiting on branch growth and mortality, gas exchange and water relations of coffee trees

2020 ◽  
Author(s):  
Wellington L Almeida ◽  
Rodrigo T Ávila ◽  
Junior P Pérez-Molina ◽  
Marcela L Barbosa ◽  
Dinorah M S Marçal ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Stomatal Density ◽  
Leaf Gas Exchange ◽  
Water Status ◽  
Co2 Concentration ◽  
Plant Hydraulics ◽  
Branch Growth ◽  
Source To Sink ◽  
Leaf Transpiration

Abstract The overall coordination between gas exchanges and plant hydraulics may be affected by soil water availability and source-to-sink relationships. Here we evaluated how branch growth and mortality, leaf gas exchange and metabolism are affected in coffee (Coffea arabica L.) trees by drought and fruiting. Field-grown plants were irrigated or not, and maintained with full or no fruit load. Under mild water deficit, irrigation per se did not significantly impact growth but markedly reduced branch mortality in fruiting trees, despite similar leaf assimilate pools and water status. Fruiting increased net photosynthetic rate in parallel with an enhanced stomatal conductance, particularly in irrigated plants. Mesophyll conductance and maximum RuBisCO carboxylation rate remained unchanged across treatments. The increased stomatal conductance in fruiting trees over nonfruiting ones was unrelated to internal CO2 concentration, foliar abscisic acid (ABA) levels or differential ABA sensitivity. However, stomatal conductance was associated with higher stomatal density, lower stomatal sensitivity to vapor pressure deficit, and higher leaf hydraulic conductance and capacitance. Increased leaf transpiration rate in fruiting trees was supported by coordinated alterations in plant hydraulics, which explained the maintenance of plant water status. Finally, by preventing branch mortality, irrigation can mitigate biennial production fluctuations and improve the sustainability of coffee plantations.

scholarly journals Ecophysiology of the Southern Highbush blueberry cv. Biloxi in response to nitrogen fertigation

2020 ◽  
Vol 11 ◽  
pp. e3245
Author(s):  
Firmino Nunes de Lima ◽  
Osvaldo Kiyoshi Yamanishi ◽  
Márcio de Carvalho Pires ◽  
Elias Divino Saba ◽  
Aline Rodrigues Pereira ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Block Design ◽  
Net Photosynthesis ◽  
Federal District ◽  
Co2 Concentration ◽  
Carboxylation Efficiency ◽  
Highbush Blueberry ◽  
Mineral Fertilization ◽  
Physiological Attributes ◽  
Southern Highbush

In Brazil, the nutritional requirements of the blueberry are not sufficiently known, thus requiring further research on the management of mineral fertilization. In this perspective, this work aimed to evaluate physiological attributes of Southern Highbush blueberry plants cv. Biloxi as a function of nitrogen fertigation in Brasília-DF. The experiment was conducted from August 2018 to July 2019, in the Fruit Sector of the Experimental Biology Station of the University of Brasilia (UnB), Federal District. This experiment adopted a randomized block design, with four treatments: 10; 20; 30, and 40 g of N plant-1, 8 replications, and 5 plants per experimental plot. The following variables were measured: net photosynthesis rate (A), transpiration (E), stomatal conductance (gs), internal CO2 concentration (Ci), instantaneous water-use efficiency (WUE), carboxylation efficiency (CE), SPAD index (SPAD) and leaf nitrogen (N). There was an effect of the different nitrogen doses applied on the physiological attributes. The plants of the blueberry cultivar Biloxi increased their photosynthetic rates at doses up to 30 g of N plant-1. Nitrogen rates did not influence stomatal conductance nor did they provide improvements in the carboxylation efficiency of the blueberry plants. Under the conditions of the present work, the highest N leaf contents were obtained with the application of 30 g N plant-1, and values above this concentration did not correspond to higher net photosynthesis rates, transpiration, and CO2 concentration in the leaf mesophyll.

scholarly journals Determination of damaged leaf area and physiological responses of melon plants submitted to different infestation levels of Liriomyza sativae

2017 ◽  
Vol 35 (4) ◽  
pp. 571-575 ◽  
Author(s):  
Ewerton M Costa ◽  
Rômulo Magno O Freitas ◽  
Paolo Augustus F Silva ◽  
Elton Lucio Araujo
Keyword(s):  
Stomatal Conductance ◽  
Leaf Area ◽  
Physiological Responses ◽  
Co2 Concentration ◽  
Internal Co2 Concentration ◽  
Liriomyza Sativae ◽  
Leaf Transpiration ◽  
Rate Of Photosynthesis ◽  
Internal Co2

ABSTRACT The leafminer Liriomyza sativae (Diptera: Agromyzidae) is one of the main pests of melon crop (Cucumis melo) in the Brazilian semiarid. The aims of this study were to determine the damaged leaf area and assess the physiological responses of melon plants submitted to different levels of infestation per larvae of L. sativae. The study was carried out in a greenhouse, using plants of melon of the cultivar Iracema (yellow melon). The design utilized was completely randomized, with five treatments {control (no infestation in the leaves) and four infestation levels (1; 10; 20 and 30 larvae per leaf)} and 10 replications (melon plants). Initially we evaluated the physiological aspects: photosynthetic rate (µmol CO2/m2/s), stomatal conductance (mol H2O/m2/s) internal CO2 concentration (µmol CO2/m2) and leaf transpiration (mmol H2O/m2/s). After the measurements of physiological aspects, the evaluated leaves of each plant were cut close to the petiole and scanned individually with a measuring scale on the side, being the determination of the damaged leaf area performed with the aid of software for processing and analysis of images. The averages of damaged leaf area observed were of 1.2; 6.3; 19.6 and 40.8 cm2 for infestations of 1; 10; 20 and 30 larvae/leaf respectively. In relation to the physiological aspects, the rate of photosynthesis, stomatal conductance and transpiration significantly decreased with the increase of leafminer larvae per leaf. The internal CO2 concentration increased with the increase in the number of larvae per leaf.

scholarly journals Impact of dust accumulation on yield and yield components of soybean

2020 ◽  
Vol 116 (1) ◽  
pp. 145
Author(s):  
Sharife HABIBPOUR ◽  
Majid AMINI DAHAGHI ◽  
Mohammad-Eghbal GHOBADI ◽  
Alaeddin KORDENAEEJ
Keyword(s):  
Stomatal Conductance ◽  
Yield Components ◽  
Block Design ◽  
Seed Mass ◽  
Growth Cycle ◽  
Yield Component ◽  
Seed Formation ◽  
Time Of Application ◽  
Randomized Complete Block Design ◽  
Beginning Of Flowering

<p>This study aimed to characterize if dust sprayed on soybean foliage impacts its yield and yield component characteristics. In 2017 and 2018, soybean [<em>Glycine max</em> (L.) Merr.] was planted using a factorial randomized complete block design with three replicates. Plants were sprayed with a 20 g m<sup>-2</sup> of dust at four stages of the growth cycle, including third-node, the beginning of flowering, the beginning of podding, and the beginning of seed formation. Dust spraying was then continued twice weekly until the late full seed stage. Plant measurements included yield, yield components, stomatal conductance, peroxidase, and superoxide dismutase antioxidant enzymes activities. Results showed that depending on the time of application, the dust coverage created a range of yield loss in soybeans, most likely due to a reduction in stomatal conductance, grains plant<sup>-1</sup> and 100-seed mass. Therefore, soybean fields that are regularly exposed to dust might be subjected to reduced yield.</p>

scholarly journals Salt stress and exogenous application of hydrogen peroxide on photosynthetic parameters of soursop

2019 ◽  
Vol 23 (4) ◽  
pp. 257-263 ◽  
Author(s):  
André A. R. da Silva ◽  
Geovani S. de Lima ◽  
Carlos A. V. de Azevedo ◽  
Luana L. de S. A. Veloso ◽  
Hans R. Gheyi ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Salt Stress ◽  
Irrigation Water ◽  
Sandy Loam ◽  
Block Design ◽  
Co2 Concentration ◽  
Co2 Assimilation ◽  
Carboxylation Efficiency ◽  
Photosynthetic Parameters ◽  
Exogenous Application

ABSTRACT This study aimed to evaluate the gas exchanges and photosynthetic pigments of soursop seedlings cv. ‘Morada Nova’ irrigated with saline waters and subjected to exogenous application of hydrogen peroxide by seed soaking and foliar spraying. The study was carried out using plastic bags under greenhouse conditions at the Center of Technology and Natural Resources of the Federal University of Campina Grande, PB, Brazil, using a eutrophic Regolithic Neosol of sandy loam texture. Treatments were arranged in a randomized block design, in 5 x 5 factorial scheme, which consisted of five levels of electrical conductivity – ECw (0.7; 1.4; 2.1; 2.8 and 3.5 dS m-1) of irrigation water and five concentrations of hydrogen peroxide - H2O2 (0, 25, 50, 75 and 100 µM), with four replicates and three plants per plot. As the salt stress increased, there were reductions in internal CO2 concentration, instantaneous carboxylation efficiency and water use efficiency, and instantaneous carboxylation efficiency was the most sensitive variable. Hydrogen peroxide at concentrations of 25 and 50 µM attenuated the deleterious effects of water salinity on stomatal conductance, CO2 assimilation rate and chlorophyll a content, and the concentration of 25 µM was the most efficient. The content of chlorophyll b and carotenoids of soursop cv. ‘Morada Nova’ had the deleterious effects caused by the salinity of irrigation water mitigated by the exogenous application of hydrogen peroxide in the concentration of 25 μM.

scholarly journals Desempenho fisiológicos e crescimento do feijão-caupi, sob manejos de plantas daninhas

2017 ◽  
Vol 12 (2) ◽  
pp. 246
Author(s):  
Uriel Calisto Moura Pessôa ◽  
Kelder José Alves de Oliveira ◽  
Anielson Dos Santos Souza ◽  
Thiago Alves Pimenta ◽  
Rafael Vitor Da Silveira Muniz ◽  
...  
Keyword(s):  
Weed Management ◽  
Block Design ◽  
Co2 Assimilation ◽  
Food Science ◽  
Gas Analyzer ◽  
Gas Exchanges ◽  
Randomized Complete Block Design ◽  
Number Of Leaves ◽  
Infrared Gas Analyzer ◽  
Direct Reflection

<p>A interferência das plantas daninhas, afeta os parâmetros de fisiológicos da cultura do feijão-caupi, com reflexo direto no crescimento e na produtividade. Assim, objetivou-se avaliar a atuação de métodos de controle das plantas daninhas na cultura do feijão-caupi, identificando o mais eficiente, por meio do acompanhamento dos componentes de crescimento, sendo estes compostos de altura (cm), número de folhas, diâmetro do caule (mm) e os aspectos fisiológicos da cultura, pela coleta de dados da taxa de assimilação de CO<sub>2</sub> (μmol m<sup>-2</sup> s<sup>-1</sup>), transpiração (mmol de H<sub>2</sub>O m<sup>-2</sup> s<sup>-1</sup>), condutância estomática (mol de H<sub>2</sub>O m<sup>-2</sup> s<sup>-1</sup>) e concentração interna de CO<sub>2</sub>, com um analisador de gás infravermelho . O experimento foi realizado em condições de campo no Centro de Ciências e Tecnologia Agroalimentar da Universidade Federal de Campina Grande, Campus Pombal, Paraíba. O delineamento experimental utilizado foi o de blocos ao acaso com oito tratamentos e quatro repetições em esquema fatorial 2 x 4, sendo os fatores: dois cultivares de feijão-caupi (BRS Marataoã e BRS Rouxinol) e quatro manejos das plantas daninhas (mecânico, químico, físico e sem controle). Os manejos químico, mecânico e físico, mostram-se superiores nos componentes de crescimento, não afetando tais características, sendo as trocas gasosas severamente afetadas.</p><p align="center"><strong><em>Physiological performance and growth of cowpea under weed management</em></strong></p><p><strong>Abstract</strong><strong>: </strong>The interference of weeds affects the physiological parameters of cowpea culture, with direct reflection on growth and productivity. The objective of this study was to evaluate the performance of different weed control methods in cowpea culture in order to identify the most efficient by monitoring the growth components, being these compounds of height (cm), number of leaves and diameter of the stem (mm) and the physiological aspects of the culture, by collecting data: CO2 assimilation rate (μmol m-2 s-1), transpiration (mmol H<sub>2</sub>O m<sup>-2</sup> s<sup>-1</sup>), Stomatal conductance (mol of H<sub>2</sub>O m<sup>-2</sup> s<sup>-1</sup>) and internal CO<sub>2 </sub>concentration, with an infrared gas analyzer. The experiment was accomplished under field conditions at the Center for Agro-Food Science and Technology of the Federal University of Campina Grande, Campus Pombal, Paraíba . The experimental design was a randomized complete block design with eight treatments and four replications in a 2 x 4 factorial scheme, being these factors: two cultivars of cowpea (BRS Marataoã and BRS Rouxinol) and four weed management (mechanical, chemical , Physical and uncontrolled). Chemical, mechanical and physical management are shown to be superior in the growth components, not affecting these characteristics, being the gas exchanges severely affected.</p>

scholarly journals Gas exchange, chemical composition and productive characteristics of tropical grasses deferred II: cultivars BRS Paiaguás and BRS Piatã

2021 ◽  
Vol 22 ◽  
Author(s):  
Francisca Gisele Rodrigues dos SANTOS ◽  
Ricardo Alves de ARAÚJO ◽  
Magno José Duarte CÂNDIDO ◽  
Marcos Cláudio Pinheiro ROGÉRIO ◽  
Clésio dos Santos COSTA ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Rainy Season ◽  
Transition Period ◽  
Structural Characteristics ◽  
Block Design ◽  
Critical Periods ◽  
Pasture Grass ◽  
Leaf Transpiration ◽  
Randomized Complete Block Design ◽  
Urochloa Brizantha

ABSTRACT This study aimed to evaluate the physiological parameters, the productive characteristics, structural and chemical composition of Urochloa Brizantha cultivars BRS and BRS Piatã submitted to two deferment periods and three using times. The experimental design was randomized complete block design in a factorial scheme 2 x 2 x 3, being two grass cultivars (Paiaguás grass and Piatã grass), two deferment periods (rainy season and dry-rainy transition) and three sealing times (40, 80 and 120 days). It was observed that, in the rainy season, the grasses had higher leaf transpiration rate when used for 40 days of deferment (1.66 µmol m2/s). During the rainy season, the Stomatal conductance was detected only in the grasses used with shorter seal, with an average of 0.07 µmol m2/s. In contrast, in the period of transition, the concentration decreased to 0.02 µmol m2/s. In a general way, the BRS Paiaguás presented lower content of NDF. The shorter cycle provided greater biomass production of total forage during the period of rain, approximately 2.78 times more than the same pasture grass deferred during the transition period. Generally, the periods of deferment and moments of use cause effects on structural characteristics of pasture, being that the period of deferment of the transition period and used for 40 and 80 days may be a strategy for keeping animals in critical periods.

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