Changes in stomatal conductance and net photosynthesis during phenological development in spring wheat: implications for gas exchange modelling

2006 ◽  
Vol 51 (1) ◽  
pp. 37-48 ◽  
Author(s):  
Johan Uddling ◽  
Håkan Pleijel
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Spring Wheat ◽  
Net Photosynthesis

scholarly journals Physiological responses of beet plants irrigated with saline water and silicon application

2020 ◽  
Vol 11 ◽  
pp. E3113
Author(s):  
José Sebastião de Melo Filho ◽  
Toshik Iarley da Silva ◽  
Anderson Carlos de Melo Gonçalves ◽  
Leonardo Vieira de Sousa ◽  
Mario Leno Martins Véras ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Carbon Concentration ◽  
Saline Water ◽  
Block Design ◽  
Essential Element ◽  
Net Photosynthesis ◽  
Crop Productivity ◽  
Experimental Unit ◽  
Randomized Block Design

Although not considered an essential element, silicon can be used to increase crop productivity, especially under stress conditions. In this sense, the objective was to evaluate the gas exchange of beet plants irrigated with saline water depending on the application of silicon. The experiment was conducted in a randomized block design, in a 5 x 5 factorial, referring to five levels of electrical conductivity of irrigation water (ECw): (0.5; 1.3; 3.25; 5.2 and 6.0 dS m-1) and five doses of silicon (0.00; 2.64; 9.08; 15.52 and 18.16 mL L-1), with six beet plants as an experimental unit. The effect of treatments on beet culture was evaluated at 30 and 60 days after irrigation with saline water from measurements of internal carbon concentration, stomatal conductance, net photosynthesis rate, instantaneous water use efficiency and instantaneous carboxylation efficiency using the LCpro+Sistem infrared gas analyzer (IRGA). Irrigation with saline water reduced the gas exchange of beet plants at 60 days after irrigation, but at 30 days after irrigation, the use of saline water increased stomatal conductance, transpiration rate and internal carbon concentration. The application of silicon decreased stomatal conductance, internal carbon concentration and efficiency in the use of water, but increased the rate of net photosynthesis, the rate of transpiration and instantaneous efficiency of carboxylation at 30 and 60 days after irrigation.

The impact of kaolin clay sprays on leaf gas exchange of Ginger Gold apple trees in New Brunswick

2006 ◽  
Vol 86 (Special Issue) ◽  
pp. 1377-1381 ◽  
Author(s):  
J. P. Privé ◽  
L. Russell ◽  
A. LeBlanc
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
New Brunswick ◽  
Leaf Gas Exchange ◽  
Net Photosynthesis ◽  
Apple Orchard ◽  
Kaolin Clay ◽  
Gas Exchange Parameters ◽  
Leaf Physiology ◽  
The Impact

A field trial was conducted over two growing seasons in a Ginger Gold apple orchard in Bouctouche, New Brunswick, Canada to examine the impact of Surround (95% kaolin clay) on leaf gas exchange [net photosynthesis (Pn), stomatal conductance (gs), intercellular CO2 (Ci) and transpiration (E)]. In 2004, a greater rate of Pn and gs was achieved at the higher than at the lower frequency of Surround applications. This was particularly notable at leaf temperatures exceeding 35°C. In 2005, no significant (P ≤ 0.05) differences among leaf residue groupings [Trace (< 0.5 g m-2), Low (0.5 to 2 g m-2), and High (≥ 2 g m-2)] were found for the four leaf gas exchange parameters at leaf temperatures ranging from 25 to 40°C. It would appear that under New Brunswick commercial orchard conditions, the application of Surround favours or has no effect on leaf gas exchange. Key words: Surround, particle film, leaf physiology, photosynthesis, stomatal conductance, intercellular CO2, transpiration

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 Parameterization of a coupled CO<sub>2</sub> and H<sub>2</sub>O gas exchange model at the leaf scale of <i>Populus euphratica</i>

2010 ◽  
Vol 14 (3) ◽  
pp. 419-431 ◽  
Author(s):  
G. F. Zhu ◽  
X. Li ◽  
Y. H. Su ◽  
C. L. Huang
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Electron Transport Rate ◽  
Populus Euphratica ◽  
Coupled Model ◽  
Net Photosynthesis ◽  
Combined Model ◽  
Validation Data ◽  
Bisphosphate Carboxylase ◽  
Diurnal Patterns

Abstract. The following two models were combined to simultaneously predict CO2 and H2O gas exchange at the leaf scale of Populus euphratica: a Farquhar et al. type biochemical sub-model of photosynthesis (Farquhar et al., 1980) and a Ball et al. type stomatal conductance sub-model (Ball et al., 1987). The photosynthesis parameters [including maximum carboxylation rate allowed by ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) carboxylation rate (Vcmax), potential light-saturated electron transport rate (Jmax), triose phosphate utilization (TPU) and day respiration (Rd)] were determined by using the genetic algorithm (GA) method based on A/Ci data. Values of Vcmax and Jmax standardized at 25 °C were 75.09±1.36 (mean ± standard error), 117.27±2.47, respectively. The stomatal conductance sub-model was calibrated independently. Prediction of net photosynthesis by the coupled model agreed well with the validation data, but the model tended to underestimate transpiration rates. Overall, the combined model generally captured the diurnal patterns of CO2 and H2O exchange resulting from variation in temperature and irradiation.

scholarly journals Gas exchange, leaf and root dry mass in Bell Pepper under fertigation with nitrogen and potassium

2018 ◽  
Vol 39 (2) ◽  
pp. 511 ◽  
Author(s):  
Marcelo Zolin Lorenzoni ◽  
Roberto Rezende ◽  
Álvaro Henrique Cândido de Souza ◽  
Fernando André Silva Santos ◽  
Cláudia Salim Lozano ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Carbon Concentration ◽  
Crop Production ◽  
Interactive Effect ◽  
Net Photosynthesis ◽  
Dry Mass ◽  
Bell Pepper ◽  
Carboxylation Efficiency ◽  
Physiological Variables

Bell pepper is a vegetable-fruit of great economic importance in Brazil. Crop production demands adequate water supply, nutrients, and light. The objective of this study was to evaluate gas exchange (net photosynthesis, stomatal conductance, transpiration, internal carbon concentration and instantaneous carboxylation efficiency) and dry mass accumulation in leaves and roots under fertigation with nitrogen and potassium. The experiment was conducted in a completely randomized design in a factorial scheme (4 × 4) with four replications and a total of 64 experimental units. Treatments consisted of a combination of four nitrogen doses (0; 73.4; 146.8 and 293.6 kg ha-1 of N) with four doses of potassium (0; 53.3; 106.7 and 213.4 kg ha-1 of K). An infrared gas analyzer (IRGA) coupled with a light source (irradiation of 600 µmol m-2 s-1) was used for the evaluation of gas exchange. There was a significant interactive effect of N and K on net photosynthesis and leaf and root dry mass. Root dry mass was the variable that best expressed this interaction. Physiological variables measured were more responsive to nitrogen fertilization than to K fertilization. The optimum values of stomatal conductance, transpiration, internal carbon concentration and carboxylation efficiency were obtained with the application of nitrogen doses between 147 and 294 kg ha-1.

Responses of Chlorophyll Fluorescence, Stomatal Conductance, and Net Photosynthesis Rates of Four Rubber (Hevea brasiliensis) Genotypes to Drought

2013 ◽  
Vol 844 ◽  
pp. 11-14
Author(s):  
Aidil Azhar ◽  
Jate Sathornkich ◽  
Ratchanee Rattanawong ◽  
Poonpipope Kasemsap
Keyword(s):  
Chlorophyll Fluorescence ◽  
Stomatal Conductance ◽  
Gas Exchange ◽  
Leaf Gas Exchange ◽  
Net Photosynthesis ◽  
Partial Recovery ◽  
Gas Exchange Parameters ◽  
Leaf Chlorophyll ◽  
Drought Conditions ◽  
Leaf Chlorophyll Fluorescence

This experiment aimed to evaluate the leaf chlorophyll fluorescence and gas exchange response to drought conditions of young rubber plants with different scions. Buds from four genotypes of a progeny derived from crossed clones of RRIM600 x RRII105 from Nongkhai Rubber Research Center, T187, T186, T149 and T172, were grafted to RRIM 600 rootstocks. Eight-month old plants with two flushes were used in this study. Two levels of water treatment were used, drought condition (W1) and well-watered as control (W0). Leaf chlorophyll fluorescence, stomatal conductance (gs) and net photosynthesis rate (Pn) were investigated in three phases: before drought, during drought and after re-watering. Leaf gas exchange parameters were measured using Li-6400 (LiCor Inc.). Leaf chlorophyll fluorescence was measured using FluorPen FP 100 (Photon Systems Instruments). Before drought, genotype T186 had the greatest net photosynthesis rates followed by T172, T187 and T149; there was no difference in maximum quantum yield of photosystem II (Fv/Fm) and performance index on absorption basis (PIABS). Drought conditions caused reduction in stomatal conductance, net photosynthesis rates, and leaf chlorophyll fluorescence in all genotypes. In re-watering conditions, genotype T186 and T172 experienced quick recovery while the others showed partial recovery but the values of all parameters did not reach previous levels before treatment.

scholarly journals Parameterization of the coupling CO<sub>2</sub> and H<sub>2</sub>O gas exchange model at the leaf scale of <i>Populus euphratica</i> tree

2009 ◽  
Vol 6 (5) ◽  
pp. 6503-6534
Author(s):  
G. Zhu ◽  
X. Li ◽  
Y. Su ◽  
C. Huang
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Populus Euphratica ◽  
Coupled Model ◽  
Net Photosynthesis ◽  
Data Sets ◽  
Validation Data ◽  
Bisphosphate Carboxylase ◽  
Diurnal Patterns ◽  
Ribulose 1

Abstract. The following two models were combined to predict simultaneously CO2 and H2O gas exchange at the leaf scale of Populus euphratica: a Farquhar et al. type biochemical sub-model of photosynthesis (Farquhar et al., 1980) and a Ball et al. type stomatal conductance sub-model (Ball et al., 1987). The photosynthesis parameters, Vcmax, Jmax, TPU, and Rd (maximum carboxylation rate allowed by ribulose 1·5-bisphosphate carboxylase/oxygenase (Rubisco), rate of phosynthetic electron transport, triose phosphate use, and day respiration) at the measurement temperature were determined by using the genetic algorithm (GA) method based on A/Ci data sets. The stomatal conductance sub-model was calibrated independently. Prediction of net photosynthesis by the coupled model agreed well with the validation data, but the model tended to underestimate rates of transpiration. Overall, the combined model generally captured the diurnal patterns of CO2and H2O exchange resulting from variation in temperature and irradiation.

scholarly journals Zinc Deficiency Inhibits Chlorophyll Synthesis and Gas Exchange in `Stuart' Pecan

HortScience ◽  
1991 ◽  
Vol 26 (3) ◽  
pp. 267-268 ◽  
Author(s):  
Hening Hu ◽  
Darrell Sparks
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Chlorophyll Content ◽  
Net Photosynthesis ◽  
Chlorophyll Synthesis ◽  
Zn Deficiency ◽  
Carya Illinoensis ◽  
Physiological Indicators ◽  
Leaf Chlorophyll ◽  
Zn Concentration

Leaves of `Stuart' pecan [Carya illinoensis (Wangenh.) C. Koch] with various levels of Zn deficiency were analyzed for physiological indicators of leaf vigor. Leaf chlorophyll content, stomatal conductance, and net photosynthesis were adversely affected by Zn deficiency. In leaves with severe Zn deficiency, each of these indicators increased 3- to 5-fold with a doubling of leaf Zn concentration, but stabilized as leaf Zn approached the sufficiency range (14 μg·g-1). High intercellular CO2 associated with low net photosynthesis indicates that stomatal aperture was not the cause of the reduction of net photosynthesis under Zn deficiency.

Water relations and gas exchange of tropical saplings during a prolonged drought in a Bornean heath forest, with reference to root architecture

2000 ◽  
Vol 16 (1) ◽  
pp. 101-116 ◽  
Author(s):  
Kun-fang Cao
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Water Status ◽  
Net Photosynthesis ◽  
Leaf Water ◽  
Deep Roots ◽  
Lower Maximum ◽  
Osmotic Acclimation ◽  
Heath Forest ◽  
Osmotic Potentials

Leaf water and osmotic potentials and gas exchange were monitored during a prolonged El Niño drought in 1998 for saplings of seven species in a Bornean heath forest and compared with measurements taken during a subsequent wet period. The four dipterocarp species maintained reasonably good water status throughout the drought, especially Dipterocarpus borneensis which had thick and deep tap roots. In contrast, two of three non-dipterocarp species, Cleistanthus baramicus and Tristaniopsis obovata displayed predawn leaf water potentials approaching their turgor-loss points. During the drought, all species except D. borneensis displayed strongly reduced stomatal conductance after a brief exposure to sun, and all displayed lower maximum rates of stomatal conductance and net photosynthesis than during the wet period. Only Cotylelobium burckii displayed significant osmotic acclimation to the drought. T. obovata possessing a superficial root system suffered a high mortality due to the drought, but recovered faster after the first rains than the other species all of which had tap roots. Deep roots and strong stomatal control favour trees in tropical heath forests where water deficits probably occur regularly.

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