Changes in leaf stomatal conductance, petiole hydraulics and vessel morphology in grapevine (Vitis vinifera cv. Chasselas) under different light and irrigation regimes

2017 ◽  
Vol 44 (7) ◽  
pp. 679 ◽  
Author(s):  
Silvina Dayer ◽  
Jorge Perez Peña ◽  
Katia Gindro ◽  
Laurent Torregrosa ◽  
Francine Voinesco ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Leaf Gas Exchange ◽  
Water Status ◽  
Growth And Yield ◽  
Research Station ◽  
The Sun ◽  
Vessel Morphology ◽  
Leaf Level ◽  
Sun And Shade ◽  
Effects Of Radiation

Hydraulic conductance and water transport in plants may be affected by environmental factors, which in turn regulate leaf gas exchange, plant growth and yield. In this study, we assessed the combined effects of radiation and water regimes on leaf stomatal conductance (gs), petiole specific hydraulic conductivity (Kpetiole) and anatomy (vessel number and size); and leaf aquaporin gene expression of field-grown grapevines at the Agroscope Research Station (Leytron, Switzerland). Chasselas vines were subjected to two radiation (sun and shade) levels combined with two water (irrigated and water-stressed) regimes. The sun and shade leaves received ~61.2 and 1.48 mol m–2 day–1 of photosynthetically active radiation, respectively, during a clear-sky day. The irrigated vines were watered weekly from bloom to veraison whereas the water-stressed vines did not receive any irrigation during the season. Water stress reduced gs and Kpetiole relative to irrigated vines throughout the season. The petioles from water-stressed vines showed fewer large-sized vessels than those from irrigated vines. The shaded leaves from the irrigated vines exhibited a higher Kpetiole than the sun leaves at the end of the season, which was partially explained by a higher number of vessels per petiole and possibly by the upregulation of some of the aquaporins measured in the leaf. These results suggest that not only plant water status but also the light environment at the leaf level affected leaf and petiole hydraulics.

Partial rootzone drying improves almond tree leaf-level water use efficiency and afternoon water status compared with regulated deficit irrigation

2011 ◽  
Vol 38 (5) ◽  
pp. 372 ◽  
Author(s):  
Gregorio Egea ◽  
Ian C. Dodd ◽  
María M. González-Real ◽  
Rafael Domingo ◽  
Alain Baille
Keyword(s):  
Gas Exchange ◽  
Water Potential ◽  
Leaf Gas Exchange ◽  
Water Status ◽  
Stem Water Potential ◽  
Regulated Deficit Irrigation ◽  
Leaf Level ◽  
Use Efficiency ◽  
Stem Water ◽  
Partial Rootzone Drying

To determine whether partial rootzone drying (PRD) optimised leaf gas exchange and soil–plant water relations in almond (Prunus dulcis (Mill.) D.A. Webb) compared with regulated deficit irrigation (RDI), a 2 year trial was conducted on field-grown trees in a semiarid climate. Five irrigation treatments were established: full irrigation (FI) where the trees were irrigated at 100% of the standard crop evapotranspiration (ETc); three PRD treatments (PRD70, PRD50 and PRD30) that applied 70, 50 and 30% ETc, respectively; and a commercially practiced RDI treatment that applied 50% ETc during the kernel-filling stage and 100% ETc during the remainder of the growth season. Measurements of volumetric soil moisture content in the soil profile (0–100 cm), predawn leaf water potential (Ψpd), midday stem water potential (Ψms), midday leaf gas exchange and trunk diameter fluctuations (TDF) were made during two growing seasons. The diurnal patterns of leaf gas exchange and stem water potential (Ψs) were appraised during the kernel-filling stage in all irrigation regimes. When tree water relations were assessed at solar noon, PRD did not show differences in either leaf gas exchange or tree water status compared with RDI. At similar average soil moisture status (adjudged by similar Ψpd), PRD50 trees had higher water status than RDI trees in the afternoon, as confirmed by Ψs and TDF. Although irrigation placement showed no effects on diurnal stomatal regulation, diurnal leaf net photosynthesis (Al) was substantially less limited in PRD50 than in RDI trees, indicating that PRD improved leaf-level water use efficiency.

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.

Exploring the sensitivity of thermal imaging for Plasmopara viticola pathogen detection in grapevines under different water status

2008 ◽  
Vol 35 (4) ◽  
pp. 281 ◽  
Author(s):  
Manfred Stoll ◽  
Hans R. Schultz ◽  
Beate Berkelmann-Loehnertz
Keyword(s):  
Stomatal Conductance ◽  
Pathogen Detection ◽  
Early Stage ◽  
Leaf Gas Exchange ◽  
Water Status ◽  
Plasmopara Viticola ◽  
Leaf Temperature ◽  
Vitis Vinifera L ◽  
Thermal Imagery ◽  
Stage Of Development

The effect on spatial variability of leaf temperature of inoculating grapevine leaves (Vitis vinifera L. cv. Riesling) with a fungal pathogen (Plasmopara viticola) was studied in either well irrigated or non-irrigated plants. The results from thermal imagery were compared with stomatal conductance measured by leaf gas exchange. The high sensitivity of leaf temperature to stomatal conductance means that infrared thermography can be used to monitor irregularities in temperature at an early stage of development after either infection or other stress-related changes affecting the amount of water transpired. Contrasting thermal effects due to the pathogen attack were found between measurements on well irrigated and water stressed plants. With irrigated vines, pathogen development caused an increase in leaf temperature at the point of infection. In contrast, under severe water stress, the inoculated plants showed a lower temperature at the sites of inoculation compared with the rest of the leaf. Analysis of the spatial and temporal sensitivity of the temperature profile, obtained from the deviation of individual pixels from the mean along a straight line, successfully distinguished between healthy and infected positions on the leaf irrespective of the plant water status. Under greenhouse conditions and for predefined areas of the leaf surface, evidence was also acquired for characteristic thermal responses to be apparent not later than 4 days past inoculation; that is, at least 3 days before visible symptoms appeared. Thus, early and remote detection using thermal imagery has the potential for pre-symptomatic diagnosis of biotic stress.

scholarly journals Coupled Gas-Exchange Model for C4 Leaves Comparing Stomatal Conductance Models

Plants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1358
Author(s):  
Kyungdahm Yun ◽  
Dennis Timlin ◽  
Soo-Hyung Kim
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Leaf Gas Exchange ◽  
Water Status ◽  
Simulation Models ◽  
Exchange Model ◽  
Modeling Framework ◽  
Wide Range ◽  
Plant Simulation ◽  
Gas Exchange Model

Plant simulation models are abstractions of plant physiological processes that are useful for investigating the responses of plants to changes in the environment. Because photosynthesis and transpiration are fundamental processes that drive plant growth and water relations, a leaf gas-exchange model that couples their interdependent relationship through stomatal control is a prerequisite for explanatory plant simulation models. Here, we present a coupled gas-exchange model for C4 leaves incorporating two widely used stomatal conductance submodels: Ball–Berry and Medlyn models. The output variables of the model includes steady-state values of CO2 assimilation rate, transpiration rate, stomatal conductance, leaf temperature, internal CO2 concentrations, and other leaf gas-exchange attributes in response to light, temperature, CO2, humidity, leaf nitrogen, and leaf water status. We test the model behavior and sensitivity, and discuss its applications and limitations. The model was implemented in Julia programming language using a novel modeling framework. Our testing and analyses indicate that the model behavior is reasonably sensitive and reliable in a wide range of environmental conditions. The behavior of the two model variants differing in stomatal conductance submodels deviated substantially from each other in low humidity conditions. The model was capable of replicating the behavior of transgenic C4 leaves under moderate temperatures as found in the literature. The coupled model, however, underestimated stomatal conductance in very high temperatures. This is likely an inherent limitation of the coupling approaches using Ball–Berry type models in which photosynthesis and stomatal conductance are recursively linked as an input of the other.

scholarly journals Physiological aspects of sun and shade leaves of Lithraea molleoides (Vell.) Engl. (Anacardiaceae)

2007 ◽  
Vol 50 (1) ◽  
pp. 91-99 ◽  
Author(s):  
Jaqueline Dias ◽  
José Antonio Pimenta ◽  
Moacyr Eurípedes Medri ◽  
Maria Regina Torres Boeger ◽  
Claudinei Toledo de Freitas
Keyword(s):  
Stomatal Conductance ◽  
Nutrient Concentration ◽  
Physiological Parameter ◽  
The Sun ◽  
Chlorophyll B ◽  
Sun And Shade Leaves ◽  
Lower Light ◽  
Sun And Shade ◽  
Shade Leaves ◽  
Sun Leaves

The aim of this work was to compare the physiological parameters of sun and shade leaves of a specimen of L. molleoides. The higher-positional leaves, classified as sun leaves, presented similar photosynthetic rate, lower chlorophyill contents (a, b and total), same a chlorophyll /b chlrorophyll rate, lower transpiratory rate, same stomatal conductance and intercellular concentration of CO2 as the lower-positional leaves, classified as shade leaves. Nutrient concentration, except for Ca and Mg, was the same for both sun and shade leaves.The physiological parameter responses indicated that although receiving lower light intensity, the shade leaves had the same capacity to grow and develop as the sun leaves.

scholarly journals Partial rootzone drying: regulation of stomatal aperture and carbon assimilation in field-grown grapevines (Vitis vinifera cv. Moscatel)

2003 ◽  
Vol 30 (6) ◽  
pp. 653 ◽  
Author(s):  
Claudia R. de Souza ◽  
João P. Maroco ◽  
Tiago P. dos Santos ◽  
M. Lucília Rodrigues ◽  
Carlos M. Lopes ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Vitis Vinifera ◽  
Isotope Composition ◽  
Leaf Gas Exchange ◽  
Water Status ◽  
Stomatal Closure ◽  
Carbon Assimilation ◽  
Quantum Yields ◽  
Vitis Vinifera L ◽  
Partial Rootzone Drying

The effects of 'partial rootzone drying' (PRD) irrigation compared with other irrigation systems, namely non-irrigated (NI), full irrigation (FI) and deficit irrigation (DI), on stomatal conductance and carbon assimilation were evaluated in field-grown grapevines (Vitis vinifera L. cv. Moscatel). At the end of the growing season, pre-dawn leaf water potential was highest in FI (–0.18 ± 0.01 MPa; mean ± s.e.), intermediate in PRD (–0.30�± 0.01 MPa) and DI (–0.36 ± 0.02 MPa), and lowest in NI vines (–0.64 ± 0.03 MPa). Stomatal conductance measured under controlled conditions of light and temperature was reduced in NI (ca 60%) and PRD (ca 30%) vines compared with DI and FI vines. Under ambient conditions, NI vines had lower rates of stomatal conductance (ca��26%), net CO2 assimilation (ca 28%) and light-adapted PSII quantum yields (ca 47%) than PRD, DI and FI vines. No significant differences were found among the three irrigated treatments. Both maximum electron transport rate (Jmax; ca 30%) and triose-phosphate utilization rates (TPU; ca 20%) were significantly lower in NI and PRD vines than in DI and FI vines. Carbon isotope composition (δ13C) of grape berries was highest in NI vines (–24.3‰), followed by PRD (–25.4‰) and DI (–25.8‰) and lowest in FI (–26.4‰) vines, suggesting a long-term increase in the efficiency of leaf gas exchange in NI compared with PRD, DI and FI vines. Sap-flow data and estimates of relative stomatal limitation are in accordance with the observed stomatal closure in PRD vines. In this study, we show that PRD irrigation was able to maintain a vine water status closed to FI, but with double water use efficiency, which was due to a reduction of stomatal conductance with no significant decrease in carbon assimilation.

Effect of intercrops on growth and yield of turmeric (Curcuma longa L.)

2017 ◽  
Vol 26 (1) ◽  
pp. 51
Author(s):  
R Chitra, P Hemalatha
Keyword(s):  
Short Duration ◽  
Agricultural Research ◽  
Curcuma Longa ◽  
Growth And Yield ◽  
Research Station ◽  
Initial Growth ◽  
Agricultural Research Station

The initial growth of turmeric is rather slow and takes about 4-5 months to cover the inter space. Therefore, the available space between the rows of turmeric could be effectively utilized by growing short duration crops like, vegetables, cereals etc. Hence, it is worthwhile to explore the possibilities of growing compatible crops with turmeric. With this background the experiment on effect of intercrops on growth and yield of turmeric was conducted at Agricultural Research Station, Bhavanisagar. Among the different intercrops, turmeric with cowpea recorded the maximum fresh rhizome yield per hectare (30.78 t ha-1) while turmeric + bhendi registered the maximum B:C ratio (2.68:1). Monocropping of turmeric recorded the lowest B:C ratio (1.67:1) among all the treatments.  

The Effects of Drought on Leaf Gas Exchange and Growth of Three Species of Herbaceous Perennials

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 540a-540
Author(s):  
K.J. Prevete ◽  
R.T. Fernandez
Keyword(s):  
Drought Stress ◽  
Stomatal Conductance ◽  
Gas Exchange ◽  
Drought Tolerance ◽  
Transpiration Rate ◽  
Leaf Gas Exchange ◽  
Gas Analysis ◽  
Herbaceous Perennials ◽  
Effects Of Drought ◽  
Analysis System

Three species of herbaceous perennials were tested on their ability to withstand and recover from drought stress periods of 2, 4, and 6 days. Eupatorium rugosum and Boltonia asteroides `Snowbank' were chosen because of their reported drought intolerance, while Rudbeckia triloba was chosen based on its reported drought tolerance. Drought stress began on 19 Sept. 1997. Plants were transplanted into the field the day following the end of each stress period. The effects of drought on transpiration rate, stomatal conductance, and net photosynthetic rate were measured during the stress and throughout recovery using an infrared gas analysis system. Leaf gas exchange measurements were taken through recovery until there were no differences between the stressed plants and the control plants. Transpiration, stomatal conductance, and photosynthesis of Rudbeckia and Boltonia were not affected until 4 days after the start of stress. Transpiration of Eupatorium decreased after 3 days of stress. After rewatering, leaf gas exchange of Boltonia and Rudbeckia returned to non-stressed levels quicker than Eupatorium. Growth measurements were taken every other day during stress, and then weekly following transplanting. Measurements were taken until a killing frost that occurred on 3 Nov. There were no differences in the growth between the stressed and non-stressed plants in any of the species. Plants will be monitored throughout the winter, spring, and summer to determine the effects of drought on overwintering capability and regrowth.

Effect of Integration of Fertilizers and FYM on Productivity and Soil Health of Rainfed Potato

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
S. K. YADAV ◽  
A. K. SRIVASTAVA ◽  
T. K. BAG
Keyword(s):  
Nutrient Management ◽  
Block Design ◽  
Soil Health ◽  
Growth And Yield ◽  
Recommended Dose ◽  
Research Station ◽  
Yield Attributes ◽  
Hill Region ◽  
North Eastern ◽  
Synthetic Fertilizers

A field trial was conducted during two consecutive summer seasons of2012 and 2013 at ICAR-Central Potato Research Station, Shillong, Meghalaya to evaluate the integration of nutrient sources on productivity and soil health under rainfed potato cultivation in north eastern hill region of India. There were six treatments of integrated nutrient management viz., 100% Recommended dose of fertilizers,75% RDF through synthetic fertilizers and 25% recommended dose of nitrogen (RDN) through FYM, 50% RDF and 50% RDN through FYM, 25% RDF and 75% RDN through FYM, 100% RDN through FYM and control (no application of any sources of nutrients). The experiment was laid out in randomized block design with four replications. Nutrient management practices showed the significant improvement on growth and yield attributes of potato over control plot. Highest productivity of potato tubers (t/ha) was noticed with application of 75% RDF through synthetic fertilizers along with 25% RDN through FYM. Similarly, the maximum net return was associated with application of 75% RDF and 25% RDN through FYM under investigation. Application of 75% Recommended dose of nutrients through synthetic fertilizers in combination with 25% Recommended dose of nitrogen through FYM was more profitable for sustainable production of potato in the north eastern hill region of India.

scholarly journals Do Camels (Camelus dromedarius) Need Shaded Areas? A Case Study of the Camel Market in Doha

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 480
Author(s):  
Martina Zappaterra ◽  
Laura Menchetti ◽  
Leonardo Nanni Costa ◽  
Barbara Padalino
Keyword(s):  
Ad Hoc ◽  
The Sun ◽  
Chi Square ◽  
Chi Square Test ◽  
Variable Space ◽  
Group 2 ◽  
Sun And Shade ◽  
Poor Welfare ◽  
Group 1

This study aimed at documenting whether dromedary camels have a preference for shade and how their behavior would change depending on the presence of shade and variable space allowance. A total of 421 animals kept in 76 pens (66 with shelter (Group 1), and 10 without shelter (Group 2)) at the camel market in Doha (Qatar) were recorded for 1 min around 11:00 a.m. when the temperature was above 40 °C. The number of animals in the sun and shade and their behaviors were analyzed using an ad libitum sampling method and an ad hoc ethogram. The results of a chi-square test indicated that camels in Group 1 had a clear preference for shade (p < 0.001). The majority of Group 1 camels were indeed observed in the shade (312/421; 74.11%). These camels spent more time in recumbency and ruminating, while standing, walking, and self-grooming were more commonly expressed by the camels in the sun (p < 0.001). Moreover, locomotory stereotypic behaviors (i.e., pacing) increased as space allowance decreased (p = 0.002). Based on the findings of this pilot study, camels demonstrated a preference for shade; shade seemed to promote positive welfare, while overcrowding seemed to trigger stereotypy and poor welfare. Overall, our preliminary results are novel and provide evidence that shaded areas are of paramount importance for camel welfare. Further research, involving designed studies at multiple locations is needed to confirm these results.

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