scholarly journals Effect of fertigation with potassium and nitrogen on gas exchange and biomass accumulation in eggplant1

2017 ◽  
Vol 47 (3) ◽  
pp. 345-352
Author(s):  
Álvaro Henrique Cândido de Souza ◽  
Roberto Rezende ◽  
Marcelo Zolin Lorenzoni ◽  
Fernando André Silva Santos ◽  
André Maller
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Water Use ◽  
Biomass Accumulation ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Co2 Concentration ◽  
Internal Co2 ◽  
Use Efficiency ◽  
Total Dry Weight

ABSTRACT Adequate crop fertilization is one of the challenges for agriculture. Measuring gas exchange and biomass accumulation may be used to adjust crop management. The effect of fertigation with potassium (0 kg ha-1, 54 kg ha-1, 108 kg ha-1 and 216 kg ha-1) and nitrogen (0 kg ha-1, 67 kg ha-1, 134 kg ha-1 and 268 kg ha-1) on gas exchange and biomass accumulation in eggplant was assessed under greenhouse conditions. The net photosynthesis, stomatal conductance, transpiration, internal CO2 concentration, instantaneous carboxylation efficiency, water-use efficiency and total dry weight were evaluated. With the exception of K for water-use efficiency and N for internal CO2 concentration, all the other gas exchange parameters were significantly affected by the K and N doses. There was an interaction between N and K doses for net photosynthesis, stomatal conductance, transpiration and instantaneous carboxylation efficiency. The highest values for net photosynthesis, stomatal conductance, transpiration rate, carboxylation instantaneous efficiency and total dry weight were found in the range of 125-185 kg ha-1 of K and 215-268 kg ha-1 of N.

scholarly journals Gas exchanges and water-use efficiency of Nopalea cochenillifera intercropped under edaphic practices

2020 ◽  
Vol 11 ◽  
pp. e3035
Author(s):  
José Thyago Aires Souza ◽  
João Everthon da Silva Ribeiro ◽  
Jucilene Silva Araújo ◽  
João Paulo de Farias Ramos ◽  
José Pereira do Nascimento ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Agricultural Research ◽  
Net Photosynthesis ◽  
Co2 Concentration ◽  
Gas Exchanges ◽  
Intrinsic Water Use Efficiency ◽  
Internal Co2 ◽  
Use Efficiency ◽  
Nopalea Cochenillifera

The Nopalea forage cactus (Nopalea cochenillifera) is the main xerophilic species cultivated in Brazil, highlighted as a compatible biological element with the semiarid environment. However, studies on its physiological aspects are still scarce. In this context, an experiment was performed in the Pendência Experimental Station, belonging to the State Company of Agricultural Research of Paraíba (EMEPA-PB), municipality of Soledade, state of Paraíba, Brazil, aiming to evaluate the gas exchanges and the water-use efficiency of intercropped Nopalea Cochenillifera plants in the soil under different edaphic managements. The treatments were distributed in randomized blocks, with three replications in a 2 × 5 factorial scheme, corresponding to the soil without and with mulch and five types of cultivation of Nopalea forage cactus, in monoculture and intercropped with forage watermelon, millet, sorghum, and buffelgrass. The analyzed variables were: stomatal conductance, transpiration rate, net photosynthesis rate, and internal CO2 concentration, besides the instantaneous water-use efficiency, intrinsic water-use efficiency, and instantaneous carboxylation efficiency. The use of soil mulch satisfactorily increased the photosynthetic rate of the forage cactus; this type of practice can aid in the productive development of the crop in semiarid zones, whereas the intercropping with buffelgrass and forage watermelon stimulated photosynthesis and the water-use efficiency.

Boron Supply and Water Deficit Consequences in Young Paricá (Schizolobium parahyba var. amazonicum) Plants

2016 ◽  
Vol 44 (1) ◽  
pp. 250-256 ◽  
Author(s):  
Bianca do Carmo SILVA ◽  
Pêola Reis de SOUZA ◽  
Daihany Moraes CALLEGARI ◽  
Vanessa Ferreira ALVES ◽  
Allan Klynger da Silva LOBATO ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Stomatal Conductance ◽  
Gas Exchange ◽  
Water Use Efficiency ◽  
Water Deficit ◽  
Water Use ◽  
Electrolyte Leakage ◽  
Tolerance Mechanism ◽  
Schizolobium Parahyba ◽  
Use Efficiency

Boron (B) is a very important nutrient required by forest plants; when supplied in adequate amounts, plants can ameliorate the negative effects of abiotic stresses. The objective of this study was to (i) investigate gas exchange, (ii) measure oxidant and antioxidant compounds, and (iii) respond how B supply acts on tolerance mechanism to water deficit in young Schizolobium parahyba plants. The experiment employed a factorial that was entirely randomised, with two boron levels (25 and 250 µmol L-1, simulating conditions of sufficient B and high B, respectively) and two water conditions (control and water deficit). Water deficit induced negative modifications on net photosynthetic rate, stomatal conductance and water use efficiency, while B high promoted intensification of the effects on stomatal conductance and water use efficiency. Hydrogen peroxide and electrolyte leakage of both tissues suffered non-significant increases after B high and when applied water deficit. Ascorbate levels presented increases after water deficit and B high to leaf and root. Our results suggested that the tolerance mechanism to water deficit in young Schizolobium parahyba plants is coupled to increases in total glutathione and ascorbate aiming to control the overproduction of hydrogen peroxide and alleviates the negative consequences on electrolyte leakage and gas exchange. In relation to B supply, this study proved that sufficient level promoted better responses under control and water deficit conditions.

scholarly journals Gas exchanges and photosynthetic efficiency in sub-forest species from Atlantic Forest

2020 ◽  
Vol 9 (5) ◽  
pp. e43952870
Author(s):  
Magnólia Martins Alves ◽  
Manoel Bandeira de Albuquerque ◽  
Renata Ranielly Pedroza Cruz ◽  
Mário Luiz Farias Cavalcanti
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Water Use ◽  
Co2 Concentration ◽  
Time Of Day ◽  
Forest Understory ◽  
Forest Species ◽  
Gas Exchanges ◽  
Endogenous Factors ◽  
Intrinsic Efficiency

The availability of light is one of the factors that most limits the photosynthesis of juvenile trees in the understory of the forest. The study was carried out in the Mata do Pau-Ferro State Park, located in the city of Areia, PB. The objective of this study was to evaluate how gas exchanges occur in individuals of Psychotria colorata (Willd. Ex Roem & Schult.), Senna georgica Irwin & Barneby, Himatanthus phagedaenicus (Mart.) Woodson, Solanum swartzianum Roem. & Schult, Psychotria carthagenensis Jacq.e Psychotria hoffmannseggiana (Willd. ex Schult.) in the understory of a remnant of Mata Atlântica. The rate of photosynthesis (A), transpiration (E), stomatal conductance (Gs), internal CO2 concentration (Ci) leaf temperature-air temperature (°C), and internal carbon (Ci), instantaneous efficiency of water use (EUA) (A/E), Intrinsic efficiency of water use (EiUC) (A/Gs) and the intrinsic efficiency of carboxylation (ratio A/Ci). The rates of maximum photosynthesis (A), photosynthesis (E) and stomatal conductance (Gs) were shown to be influenced by the time of day, as there was no interference of external factors in the diurnal patterns of gas exchange, variations are due to endogenous factors, probably due to the circadian rhythm. The parameter of the gas exchange of sub-forest species responds differently, in the small variations in the luminosity levels of the forest understory

scholarly journals Development, Physiology and Productivity of the Common Bean Under Different Nitrogen Doses

2018 ◽  
Vol 10 (6) ◽  
pp. 171
Author(s):  
João Everthon da Silva Ribeiro ◽  
Arliston Pereira Leite ◽  
José Eldo Costa ◽  
Manoel Bandeira de Albuquerque ◽  
Fábio Mielezrski
Keyword(s):  
Gas Exchange ◽  
Common Bean ◽  
Co2 Concentration ◽  
Fluorescence Maximum ◽  
Internal Co2 ◽  
Common Bean Cultivar ◽  
Number Of Leaves ◽  
Use Efficiency ◽  
The Common ◽  
Pod Number

Among nutrients, nitrogen is required in the greatest quantities by bean culture. The objective of this work was to evaluate growth, physiological responses and productivity of the common bean cultivar, ‘IAC Imperador’ under varying nitrogen doses in Brejo Paraibano. The experiment was carried out at Fazenda Experimental Chã-de-Jardim (Chã-de-Jardim Experimental Farm), of the Centro de Ciências Agrárias of the Universidade Federal da Paraíba, in the municipality of Areia, state of Paraíba. The treatments comprised 0, 50, 100, 150 and 200 kg of nitrogen ha-1, applied in coverage at 35 days after sowing. To assess growth, plant height, stem diameter and number of leaves were evaluated. For gas exchange, photosynthesis rate, internal CO2 concentration, transpiration, stomatal conductance, instantaneous water use efficiency and instantaneous carboxylation efficiency were evaluated. For chlorophyll “a” fluorescence, minimum leaf fluorescence, maximum leaf fluorescence, variable maximum fluorescence, potential quantum efficiency of PSII (Photosystem II) and ratio (Fv/F0) were evaluated. For the components of primary productivity, the height of insertion of the first pod, number of pods per plant and the number of grains per pod were evaluated. Nitrogen fertilization in coverage significantly affected most of the growth, gas exchange and productivity variables, with the dose of 200 kg ha-1 being responsible for the highest values (p < 0.05). Chlorophyll fluorescence showed no significant differences among the nitrogen doses. The nitrogen doses influenced the growth, gas exchange and productivity of the common bean in the region of Brejo Paraibano. 

scholarly journals Variability among Young Table Grape Cultivars in Response to Water Deficit and Water Use Efficiency

Agronomy ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 135 ◽  
Author(s):  
Carolin Weiler ◽  
Nikolaus Merkt ◽  
Jens Hartung ◽  
Simone Graeff-Hönninger
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Water Deficit ◽  
Water Use ◽  
Dry Mass ◽  
Table Grape ◽  
Water Limitation ◽  
Use Efficiency ◽  
Response To Water ◽  
Grape Cultivars

Climate change will lead to higher frequencies and durations of water limitations during the growing season, which may affect table grape yield. The aim of this experiment was to determine the variability among 3-year old table grape cultivars under the influence of prolonged water deficit during fruit development on gas exchange, growth, and water use efficiency. Six own rooted, potted table grape cultivars (cv. ‘Muscat Bleu’, ‘Fanny’, ‘Nero’, ‘Palatina’, ‘Crimson Seedless’ and ‘Thompson Seedless’) were subjected to three water deficit treatments (Control treatment with daily irrigation to 75% of available water capacity (AWC), moderate (50% AWC), and severe water deficit treatment (25% AWC)) for three consecutive years during vegetative growth/fruit development. Water deficit reduced assimilation, stomatal conductance, and transpiration, and increased water use efficiencies (WUE) with severity of water limitation. While leaf area and number of leaves were not affected by treatments in any of the tested cultivars, the response of specific leaf area to water deficit depended on the cultivar. Plant dry mass decreased with increasing water limitation. Overall, high variability of cultivars to gas exchange and water use efficiencies in response to water limitation was observed. ’Palatina’ was the cultivar having a high productivity (high net assimilation) and low water use (low stomatal conductance) and the cultivar ‘Fanny’ was characterized by the highest amount of total annual dry mass as well as the highest total dry mass production per water supplied during the experiment (WUEDM). Hence, ‘Fanny’ and ‘Palatina’ have shown to be cultivars able to cope with water limiting conditions and should be extensively tested in further studies.

Effects of substrate acidity and UV-B radiation on photosynthesis of radishes

2011 ◽  
Vol 6 (4) ◽  
pp. 624-631
Author(s):  
Irena Januskaitiene
Keyword(s):  
Gas Exchange ◽  
Water Use ◽  
Raphanus Sativus ◽  
Net Photosynthesis ◽  
Enzymatic Reactions ◽  
Growth Substrate ◽  
Gas Exchange Parameters ◽  
Raphanus Sativus L ◽  
Use Efficiency ◽  
Exchange Parameters

AbstractThe aim of this study was to assess the combined effect of substrate acidity (pH 4.8; pH 3.8) and 1 kJm−2d−1 UV-B radiation on photosynthesis and growth of radishes (Raphanus sativus L.). Radishes were sown in a neutral pH 6.5 peat substrate. When the second true leaf unfolded, the growth substrate was acidified using different concentration of H2SO4 and exposed to UV-B radiation for a period of ten days. Gas exchange parameters were measured with the LI-6400 portable photosynthesis system. Content of chlorophyll was evaluated spectrophotometrically. The results showed that the greatest inhibition of net photosynthesis was observed when radishes were grown in an acidified pH 3.8 substrate. The decrease of the photosynthesis of radish plants treated with both investigated factors (substrate acidity and UV-B) were lower compared to the effect of substrate acidity alone. UV-B radiation stimulated both enzymatic reactions of photosynthesis and water use efficiency of radish plants grown in acidified peat substrates. Also, investigated factors had higher impact on biomass of tuber than biomass of foliage.

Physiological acclimation of Pinus flexilis to drought stress on contrasting slope aspects in Waterton Lakes National Park, Alberta, Canada

2009 ◽  
Vol 39 (3) ◽  
pp. 629-641 ◽  
Author(s):  
Matthew G. Letts ◽  
Kevin N. Nakonechny ◽  
K. Eric Van Gaalen ◽  
Cyndi M. Smith
Keyword(s):  
Gas Exchange ◽  
Water Use ◽  
Isotope Composition ◽  
Stable Carbon Isotope ◽  
Vapour Pressure Deficit ◽  
Net Photosynthesis ◽  
Pinus Flexilis ◽  
Limber Pine ◽  
Use Efficiency ◽  
Physiological Acclimation

Photosynthetic gas-exchange characteristics were measured in Pinus flexilis James (limber pine) during two drought years in a xeric, subalpine ecosystem of the Rocky Mountains. Limber pine exhibited conservative water-use traits, including low specific leaf area, leaf nitrogen, stomatal conductance, transpiration (E), and light-saturated net photosynthesis (Amax), but exhibited high needle longevity, water-use efficiency (Amax/E), and stable carbon isotope composition. Net photosynthesis declined strongly with leaf-to-air vapour pressure deficit, resulting in a bimodal seasonal pattern of Amax. Although very little gas exchange was observed in late summer, photosynthetic activity extended into October. The avoidance of gas exchange during high atmospheric demand maximized whole-season water-use efficiency. Leaf temperature and leaf-to-air vapour pressure deficit were higher on south-facing slopes during both moderate (2006) and severe (2007) drought. Severe drought caused lower stomatal conductance and E on the southeast-facing slope, but neither Amax nor canopy reflectance indices differed among slope aspects. Although Amax was lower in 2007 than 2006, branch-length increment did not differ. Foliar stable carbon isotope composition was higher in needles produced in dry years but did not vary among slope aspects. These results indicate that physiological acclimation to water stress prevented among-aspect differences in Amax and that shoulder-season photosynthesis may become increasingly important in a warmer climate.

scholarly journals Leaf gas exchange and chlorophyll index in guava fertirrigated with bovine biofertilizer and nitrogen

2020 ◽  
Vol 9 (9) ◽  
pp. e588997606
Author(s):  
Elisson Alves Santana ◽  
Francisco Eduardo dos Santos Gomes ◽  
Jackson Teixeira Lobo ◽  
Alberto de Andrade Soares Filho ◽  
Ítalo Herbert Lucena Cavalcante ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Leaf Gas Exchange ◽  
Net Photosynthesis ◽  
Co2 Concentration ◽  
Psidium Guajava ◽  
N Fertilization ◽  
Chl A ◽  
Internal Co2 ◽  
Chlorophyll Index ◽  
Photosynthetic Responses

The objective of this work was to evaluate the influence of fertirrigation with nitrogen and liquid bovine biofertilizer on gas exchange and leaf chlorophyll index of 'paluma' guava (Psidium guajava L.). The experimental design was randomized blocks with treatments distributed in a factorial arrangement (2 × 4) referring to mineral fertilizing with N (50% and 100% of N recommended) and biofertilizer concentrations (0, 2.5, 5.0 and 7.5% of the fertirrigated volume). Variables evaluated were chlorophyll a (Chl a), chlorophyll b (Chl b), total chlorophyll indexes (Chltotal), internal CO2 concentration (Ci), stomatal conductance (gs), transpiration (E), net photosynthesis (A), instant carboxylation efficiency (iCE) and water use efficiency (WUE). The biofertilizer significantly affected Chl a, Chl b, Chltotal, A, gs and E, with quadratic polynomial adjustment of the results. However, there was no effect of N fertilization and interaction between the factors. Maximum index of Chltotal was 32.31 obtained with the estimated dose of 3.8% of the biofertilizer; while A, gs and E presented maximum responses of 19.09 µmol of CO2 m-2 s-1, 0.28 mol of H2O m-2 s-1 and 4.93 mmol of H2O m-2 s-1, with estimated doses of 3.6%, 3.6%, and 3.7%, respectively. Generally, liquid bovine biofertilizer applied via fertirrigation affects positively the photosynthetic responses in 'paluma' guava, however, with decreasing effects for doses above 3.8%.

Another View of Gas Exchange Model: Reflection of Leaf Surface Air to Stomatal Conductance

2010 ◽  
Vol 113-116 ◽  
pp. 14-17
Author(s):  
Meng Hu ◽  
Shao Zhong Kang ◽  
Tai Sheng Du ◽  
Ling Tong
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Leaf Surface ◽  
Leaf Gas Exchange ◽  
Exchange Process ◽  
Negative Relationship ◽  
Co2 Concentration ◽  
Reflection Function ◽  
Use Efficiency ◽  
Gas Exchange Process

A reflection function was established, based on leaf gas exchange process and tested with experimental data of eight kinds of plants, i.e. tomato, muskmelon, capsicum, maize, grape, onion, Haloxylon Ammodendron Bunge and Caragana Karshiskii Kom, with multifarious biological characteristic, water and growing status. The function indicated that the leaf stomatal conductance could be linearly reflected by the ratio of humidity and CO2 concentration at leaf surface, and the behaviour of its slope could be recognized as an indicator of leaf gas exchange efficiency, which had a negative relationship with leaf water use efficiency (WUE). The results maybe increase our understanding of potential influences of leaf stomatal conductance on photosynthetic and transpiration gas exchange and leaf WUE.

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