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 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.

scholarly journals Stem and leaf anatomical and physiological characteristics of ‘Colín V-33’ avocado seedlings

2021 ◽  
Vol 35 (2) ◽  
Author(s):  
Nora Virginia Useche-Carrillo ◽  
Alejandro Facundo Barrientos-Priego ◽  
Carlos Alberto Núñez-Colín ◽  
Eduardo Campos-Rojas ◽  
Juan Ayala-Arreola
Keyword(s):  
Stomatal Conductance ◽  
Early Stage ◽  
Stem Diameter ◽  
Improvement Program ◽  
Group 4 ◽  
Stage Of Development ◽  
Physiological Structure ◽  
Group 3 ◽  
Selection Parameters ◽  
Stem Leaf

The anatomical and physiological structure of the ‘Colín V-33’ avocado stem and leaf is described from samples from plants obtained from seed in order to identify genotypes and early selection parameters in a rootstock improvement program for avocado. Eighty-nine plants of 12 months of age were used, where a total of 25 anatomical variables of the stem, leaf, and physiological of leaf were evaluated. A cluster analysis was conducted that generated a hierarchical dendrogram that suggested six groups of plants. Furthermore, from the 25 variables, eight were selected as discriminant when performing a canonical discriminant analysis, the variables that most discriminated for the first canonical component were: stem diameter and density of xylem vessels, for the second: thickness of the stem epidermis, temperature of the stem leaf and stomata length, while for the third: thickness of the cambium, transpiration rate, and stomatal conductance. The genotypes showed a great variation between the groups, the characteristics of these indicated that the genotypes of Group 4 showed some that could be related to small or dwarf plants (smaller stem diameter, high density of xylem vessels, a higher rate of transpiration and stomatal conductance). In contrast to the genotypes of Group 3 which presented opposite characteristics in the previous variables, being able to associate with vigorous plants. The anatomical traits of the stem showed to be highly related to the behavior of the avocado plants. Associating genotypes with physiological and anatomical variables in leaf and stem can have great value for the selection of rootstocks at an early stage of development.

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 The Lanata trichome mutation increases stomatal conductance and reduces leaf temperature in tomato

2020 ◽  
Author(s):  
Karla Gasparini ◽  
Ana Carolina R. Souto ◽  
Mateus F. da Silva ◽  
Lucas C. Costa ◽  
Cássia Regina Fernandes Figueiredo ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Spectral Properties ◽  
Growth Parameters ◽  
Stomatal Density ◽  
Leaf Gas Exchange ◽  
Glandular Trichomes ◽  
Glandular Trichome ◽  
Leaf Temperature ◽  
Trichome Density

ABSTRACTBackground and aimsTrichomes are epidermal structures with an enormous variety of ecological functions and economic applications. Glandular trichomes produce a rich repertoire of secondary metabolites, whereas non-glandular trichomes create a physical barrier against biotic and abiotic stressors. Intense research is underway to understand trichome development and function and enable breeding of more resilient crops. However, little is known on how enhanced trichome density would impinge on leaf photosynthesis, gas exchange and energy balance.MethodsPrevious work has compared multiple species differing in trichome density, instead here we analyzed monogenic trichome mutants in a single tomato genetic background (cv. Micro-Tom). We determined growth parameters, leaf spectral properties, gas exchange and leaf temperature in the hairs absent (h), Lanata (Ln) and Woolly (Wo) trichome mutants.Key resultsShoot dry mass, leaf area, leaf spectral properties and cuticular conductance were not affected by the mutations. However, the Ln mutant showed increased carbon assimilation (A) possibly associated with higher stomatal conductance (gs), since there were no differences in stomatal density or stomatal index between genotypes. Leaf temperature was furthermore reduced in Ln in the early hours of the afternoon.ConclusionsWe show that a single monogenic mutation can increase glandular trichome density, a desirable trait for crop breeding, whilst concomitantly improving leaf gas exchange and reducing leaf temperature.HIGHLIGHTA monogenic mutation in tomato increases trichome density and optimizes gas exchange and leaf temperature

scholarly journals Effect of Genotype and Organic Fertilizer on Red:Far Red Ratio, Stomatal Conductance, Leaf Temperature, and Dry Weight of Amaranth

2014 ◽  
Vol 47 (3) ◽  
pp. 79-86
Author(s):  
Samson Baranzan Wayah ◽  
Ajit Singh ◽  
Peter Maitalata Waziri ◽  
Zheng-Yew Theng ◽  
Bruno Martins Nkem ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Water Status ◽  
Organic Fertilizer ◽  
Dry Weight ◽  
Leaf Temperature ◽  
Significant Interaction Effect ◽  
Strong Negative Correlation ◽  
Amaranthus Caudatus ◽  
Application Rates ◽  
Growth Indicators

Abstract Amaranth is a very important vegetable worldwide. Its leaves are consumed and the seeds are processed into various food products. Its production in the tropics is threatened by low yields which has a major impact on global production. A research aimed at improving the yield of this vegetable was carried out at lady bird organic farm Broga, 2.9450N 101.8740E, Semenyih, Selangor, Malaysia by studying the effect of genotype and organic fertilizer on the following growth indicators, red:far red ratio below canopy, stomatal conductance, leaf temperature, and dry weight. These growth indicators were monitored on a weekly basis over a period of six weeks. Three genotypes namely, Amaranthus caudatus, 3388 (green round leaf), Amaranthus caudatus, 3233 (green long leaf) and Amaranthus cruentus, 888 (red leaf) were grown on soils to which organic fertilizer was added at three different application rates (0 t/ha, 7.5 t/ha and 15 t/ha). There was no significant interaction effect of genotype and organic fertilizer on the growth indicators; however, each of these factors had significant effect on the growth of amaranth. A strong negative correlation occurred between dry weight and red:far red ratio below canopy likewise, between stomatal conductance and leaf temperature. Over a cultivation period of five weeks, the green long leaf genotype was superior showing that it is better adapted to growing in the rainforest agro ecological zone of Malaysia than the other two genotypes. Organic fertilizer application at a rate of 15 t/ha produced the lowest leaf temperature, after 4 weeks of cultivation implying better water status than 0 t/ha and 7.5 t/ha application rates. This study clearly shows that genotype and organic fertilizer have significant effect on the growth of amaranth. Therefore, these factors can be manipulated in order to enhance amaranth production.

scholarly journals A continuum of stomatal responses to water deficits among 17 wine grape cultivars (Vitis vinifera)

2020 ◽  
Vol 47 (1) ◽  
pp. 11 ◽  
Author(s):  
Alexander D. Levin ◽  
Larry E. Williams ◽  
Mark A. Matthews
Keyword(s):  
Stomatal Conductance ◽  
Vitis Vinifera ◽  
Water Status ◽  
Stomatal Closure ◽  
Vitis Vinifera L ◽  
Water Deficits ◽  
Stomatal Behaviour ◽  
Relationship Of ◽  
The Relationship ◽  
Maximum Stomatal Conductance

Vitis vinifera L. cultivars have been previously classified as isohydric, near-isohydric, anisohydric or isohydrodynamic, depending on the study. To test the hypothesis that V. vinifera cultivars’ stomatal behaviour can be separated into distinct classes, 17 cultivars grown in a replicated field trial were subjected to three irrigation treatments to manipulate vine water status across multiple years. Predawn (ΨPD) and midday (Ψl) leaf water potential and midday stomatal conductance (gs) were measured regularly throughout several seasons. The relationship of gs to Ψl was best modelled as a sigmoidal function and maximum stomatal conductance (gmax), water status at the onset of stomatal closure (Ψl95), sensitivity of closure (gsensitivity) and water status at the end of closure (Ψl25) were compared. There were no significant differences in gmax among cultivars. Cultivar-specific responses of gs to Ψl were broadly distributed along a continuum based on the relationship between Ψl95 and gsensitivity. Season-long cultivar mean Ψl values were positively related to Ψl25. In general, cultivars responded similarly to one another at high and low water status, but their stomatal behaviour differed at moderate water deficits. The results show that V. vinifera cultivars possess both iso- and anisohydric stomatal behaviours that depend on the intensity of water deficits, and call into question previous classifications assuming a single behaviour.

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.

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.

The influence of water stress on grapevine (Vitis vinifera L.) shoots in a cool, humid climate: growth, gas exchange and hydraulics

2016 ◽  
Vol 43 (9) ◽  
pp. 827 ◽  
Author(s):  
Vinay Pagay ◽  
Vivian Zufferey ◽  
Alan N. Lakso
Keyword(s):  
Soil Moisture ◽  
Water Stress ◽  
Gas Exchange ◽  
Vitis Vinifera ◽  
Leaf Gas Exchange ◽  
Water Status ◽  
Large Diameter ◽  
Vitis Vinifera L ◽  
Long Shoots ◽  
Short Shoots

Recent climatic trends of higher average temperatures and erratic precipitation patterns are resulting in decreased soil moisture availability and, consequently, periods of water stress. We studied the effects of seasonal water stress on grapevine (Vitis vinifera L. cv. Riesling grafted onto 101–14 (Vitis riparia Michx.×Vitis rupestris Scheele) rootstock) shoot growth, leaf gas exchange, xylem morphology and hydraulic performance in the cool-climate Finger Lakes region of New York. A plastic rain exclusion tarp was installed on the vineyard floor to create a soil moisture deficit and consequently induce vine water stress. Weekly measurements of predawn leaf and midday stem water potentials (Ψmd) were made, and two contrasting shoot length classes, long (length >2.0m) and short (length <1.0m), were monitored. Growth of both long and short shoots was positively correlated with Ψmd but no difference in water status was found between the two. Compared with rain-fed vines, water-stressed vines had lower photosynthesis and stomatal conductance later in the season when Ψmd dropped below –1.2MPa. Long shoots had three-fold higher xylem-specific hydraulic conductivity values than short shoots. Long shoots experiencing water stress were less vulnerable to xylem cavitation than shorter shoots even though they had more large-diameter vessels. The lower vulnerability to cavitation of long shoots may be attributed to less xylem intervessel pitting being found in long shoots, consistent with the air-seeding hypothesis, and suggests that a hydraulic advantage enables them to maintain superior growth and productivity under water stress.

scholarly journals Effects of natural clinoptilolite on physiology, water stress, sugar, and anthocyanin content in Sanforte (Vitis vinifera L.) young vineyard

2021 ◽  
pp. 1-12
Author(s):  
E. C. Cataldo ◽  
L. S. Salvi ◽  
F. P. Paoli ◽  
M. F. Fucile ◽  
G. M. Masciandaro ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Stress ◽  
Leaf Gas Exchange ◽  
Sugar Content ◽  
Climatic Conditions ◽  
Leaf Temperature ◽  
Vitis Vinifera L ◽  
Anthocyanin Content ◽  
Stem Water Potential ◽  
Technological Parameters

Abstract In the Mediterranea area, major effects of climate change are a modification in rainfall patterns, an increase in temperature with an intensify in tropical nights, and an increase in incoming radiations, especially UV-Bs. Despite the various adaptation strategies, grapevines are sensitive to altered climatic conditions. This paper aims to assess the benefits of applying a new sustainable product to the soil that can implement farmers’ resources to adapt to this changing situation. Zeowine was realized by combining the properties of zeolite, which has excellent potential in many sectors such as in agriculture, with the organic substance of a compost obtained on a company scale from the reuse of waste processing grapes, pomace and stalks. The effects of two different soil management (Z – Zeowine, 30 t/ha dose and C – Compost, 20 t/ha dose) on vine physiology and berry compositions in Sanforte grapevines (new plantation) were studied during the 2019–2020–2021 growing seasons in the San Miniato area, Italy. The following physiological parameters of grapevines were measured: leaf gas exchange, leaf temperature, stem water potential and chlorophyll fluorescence. The results showed that Z increased single leaf photosynthesis, reduced leaf temperature and water stress. In addition, phenolic and technological parameters were studied. The Z-treated vines had higher sugar content and total and extractable anthocyanin content as well as berry weight. These results suggested that the application of zeolites added to compost in the vineyard to the soil can be a valid tool to mitigate the effects of climate change.

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