A Two-Big-Leaf Model for Canopy Temperature, Photosynthesis, and Stomatal Conductance

AbstractVariability in soil moisture on a steep slope near a ridge in a forested mountain range, Shikoku, Japan, was studied observationally and numerically. Vertically integrated soil moisture, from a depth of −60 cm to the surface, W, was introduced as a key indicator, and its seasonal variation was analysed on a daily basis from August 2011 to August 2012. The “bucket with a bottom hole” (BBH) model of Teshima et al. (2006) was improved to consider the forest environment in simulating the variation in W. A “big-leaf” model was incorporated into the modified BBH model to estimate transpiration and interception by trees. The simulated soil moisture agreed reasonably with observed values on a daily to inter-seasonal timescale.

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Evaluation of Water Stress on Yield, Its Components and Some Physiological Traits at Different Growth Stages in Grain Sorghum Genotypes

Notulae Scientia Biologicae ◽

10.15835/nsb829790 ◽

2016 ◽

Vol 8 (2) ◽

pp. 204-210

Author(s):

Ali AZARINASRABAD ◽

Seyyed Mohsen MOUSAVINIK ◽

Mohammad GALAVI ◽

Seyyed Alireza BEHESHTI ◽

Alireza SIROUSMEHR

Keyword(s):

Water Stress ◽

Stomatal Conductance ◽

Canopy Temperature ◽

Grain Sorghum ◽

Physiological Traits ◽

Stay Green ◽

Use Efficiency ◽

Chlorophyll Index ◽

Sorghum Genotypes ◽

Radiation Use

Investigation on yield improvement and development under drought condition using breeding techniques is difficult, due to the association with low heritability of specific traits. Even more, investigation of physiological indicators (stomatal conductance, chlorophyll index, relative water content, chlorophyll fluorescence, canopy temperature, radiation use efficiency, stay-green etc.) is of interest as they are more accessible, with a low cost, therefore these indicators of physiological traits can be used as good criteria in selecting valuable species. In order to evaluate the effects of water stress on grain yield, its components and some physiological traits of grain sorghum genotypes (Sorghum bicolor L.), a field experiment using split plot design with three replications was carried. The main plots included three water stress treatments: normal irrigation as control, halting irrigation at the stage of terminal leaf emergence and halting irrigation at the stage of 50% flowering. The sub-plots included 10 genotypes of sorghum (‘KGS29’, ‘MGS2’, ‘Sepideh’, ‘KGFS27’, ‘MGS5’, ‘KGFS5’, ‘KGFS17’, ‘KGFS13’ and ‘KGFS30’). Results showed that water stress significantly decreased grain yield and its components (1,000 seed weight, number of seed per panicle) and had various effects on physiological traits. The water stress increased canopy temperature and radiation use efficiency, while stomatal conductance, chlorophyll index (SPAD) and stay-green of genotypes were decreased; the maximum efficiency of photosystem II of photosynthesis remained unchanged between the treatments. Genotypes turned out to have significantly different responses to the drought treatments for all the studied traits, indicating the existence of a high variability among them. In general, physiological traits could be used as good indicators in water stress investigations and might provide comprehensive information as compared with morphological traits.

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Physiological Factors and their Relationship with the Productivity of Processing Tomato under Different Water Supplies

Water ◽

10.3390/w11030586 ◽

2019 ◽

Vol 11 (3) ◽

pp. 586 ◽

Cited By ~ 6

Author(s):

Eszter Nemeskéri ◽

András Neményi ◽

András Bőcs ◽

Zoltán Pék ◽

Lajos Helyes

Keyword(s):

Stomatal Conductance ◽

Significant Influence ◽

Water Status ◽

Canopy Temperature ◽

Irrigation Scheduling ◽

Fruit Weight ◽

Processing Tomato ◽

Spad Value ◽

Yield And Quality ◽

Fruit Setting

Measurement of physiological traits can be used to monitor plant water status, for irrigation scheduling or to predict the expected yield in open-field production of vegetables. This study evaluates the changes in stomatal conductance, chlorophyll fluorescence (Fv/Fm), relative chlorophyll content (SPAD), and canopy temperature at different stages of development of processing tomato to show their relationships with the yield and quality under well-irrigated, deficit irrigated, and non-irrigated conditions. Under non-irrigated conditions, during flowering with fruit setting and early fruit development the highest canopy temperature, lowest stomatal conductance, and Fv/Fm were measured, while the SPAD value was the highest. Under this condition, the correlation between the SPAD value, fruit weight, and marketing yield was positive, but it was negative with the total soluble solid (°Brix). During flowering with fruit setting, under deficit irrigation conditions a close significant positive correlation was found between the SPAD value and the fruit weight, marketing yield, and vitamin C content of fruits. During this period, under regularly irrigated conditions, the SPAD, Fv/Fm, and canopy temperature related to stomatal conductance. Stomatal conductance had significant influence on yield and quality under non-irrigated and well-irrigated conditions while the SPAD value and canopy temperature had significant influence on under deficit irrigated conditions.

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The behaviour of a mixed-layer model of the convective boundary layer coupled to a big leaf model of surface energy partitioning

Boundary-Layer Meteorology ◽

10.1023/a:1001110819090 ◽

1998 ◽

Vol 88 (1) ◽

pp. 87-101 ◽

Cited By ~ 35

Author(s):

C. Huntingford ◽

J. L. Monteith

Keyword(s):

Boundary Layer ◽

Surface Energy ◽

Mixed Layer ◽

Convective Boundary Layer ◽

Energy Partitioning ◽

Layer Model ◽

Convective Boundary ◽

Big Leaf Model ◽

Leaf Model ◽

Mixed Layer Model

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Canopy Temperature as a Key Physiological Trait to Improve Yield Prediction under Water Restrictions in Potato

Agronomy ◽

10.3390/agronomy11071436 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1436

Author(s):

Johan Ninanya ◽

David A. Ramírez ◽

Javier Rinza ◽

Cecilia Silva-Díaz ◽

Marcelo Cervantes ◽

...

Keyword(s):

Decision Support ◽

Stomatal Conductance ◽

Mean Squared Error ◽

Satellite Image ◽

Model Performance ◽

Canopy Temperature ◽

Coefficient Of Determination ◽

Yield Prediction ◽

Crop Models ◽

Water Treatments

Canopy temperature (CT) as a surrogate of stomatal conductance has been highlighted as an essential physiological indicator for optimizing irrigation timing in potatoes. However, assessing how this trait could help improve yield prediction will help develop future decision support tools. In this study, the incorporation of CT minus air temperature (dT) in a simple ecophysiological model was analyzed in three trials between 2017 and 2018, testing three water treatments under drip (DI) and furrow (FI) irrigations. Water treatments consisted of control (irrigated until field capacity) and two-timing irrigation based on physiological thresholds (CT and stomatal conductance). Two model perspectives were implemented based on soil water balance (P1) and using dT as the penalizing factor (P2), affecting the biomass dynamics and radiation use efficiency parameters. One of the trials was used for model calibration and the other two for validation. Statistical indicators of the model performance determined a better yield prediction at harvest for P2, especially under maximum stress conditions. The P1 and P2 perspectives showed their highest coefficient of determination (R2) and lowest root-mean-squared error (RMSE) under DI and FI, respectively. In the future, the incorporation of CT combining low-cost infrared devices/sensors with spatial crop models, satellite image information, and telemetry technologies, an adequate decision support system could be implemented for water requirement determination and yield prediction in potatoes.

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Effect of water supply on canopy temperature, stomatal conductance and yield quantity of processing tomato (Lycopersicon esculentum Mill.)

International Journal of Horticultural Science ◽

10.31421/ijhs/16/5/926 ◽

2010 ◽

Vol 16 (5) ◽

Cited By ~ 1

Author(s):

L. Helyes ◽

A. Bőcs ◽

Z. Pék

Keyword(s):

Stomatal Conductance ◽

Lycopersicon Esculentum ◽

Water Supply ◽

Canopy Temperature ◽

Tomato Plants ◽

Horticultural Crops ◽

Processing Tomato ◽

Lycopersicon Esculentum Mill ◽

Plant Stand ◽

Positive Effect

Tomato (Lycopersicon esculentum Mill.) is one of the most extensively cultivated horticultural crops in the world.Water supply is important for yield quantity and quality. The aims of the present study were 1) to evaluate the canopy temperature and the stomatal conductance on processing tomato substances with different water supply, 2) to investigate the effect of different water supply on yield quantity. There were two irrigated treatments, one of them was the reguralry irrigated plant stand which got 333 mm water during investigated period, including the precipitation and the other was the cut off substance which means the irrigation (drip) was stopped at the beginning of the ripening process and there was a control as well which got 189 mm precipitation. The canopy temperature was measured row by row with a Raytek MX 4 type infrared remote thermometer. The stomatal conductance was measured by Delta-T AP4 type porometer. There were significant differences between the control and irrigated plants according to the water supply which was formulated the canopy values. The plants with a deficient water supply were decreased the transpiration rate, therefore its cooling effect didn’t show up. The regularly irrigated tomato plants’ yield exceeded the unirrigated ones more than twice. It is emerged from the study that the irrigation has a positive effect on the amount of the harvestable yield in this year type.

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Scaling leaf photosynthesis to canopy in a mixed deciduous forest. II. A simulation study for two growing seasons

Silva Gandavensis ◽

10.21825/sg.v62i0.843 ◽

1997 ◽

Vol 62 ◽

Author(s):

R. Samson ◽

S. Follens ◽

R. Lemeur

Keyword(s):

Forest Canopy ◽

Deciduous Forest ◽

Growing Season ◽

Limiting Factor ◽

Canopy Photosynthesis ◽

Growing Seasons ◽

Mixed Deciduous Forest ◽

Leaf Level ◽

Big Leaf Model ◽

Leaf Model

The model as described in Samson et al. (1997) (FORUG model) is validated at the leaf level, and seems to simulate well the canopy rates for the different species and the different considered layers in the canopy. The highest instantaneous canopy photosynthesis rates are found for oak, the lowest for beech. The total amount of carbon assimilated during the growing season was highest for oak and ash and lower for beech and amounted respectively 10.9, 11.0 and 10.3 ton C ha-1 y-1 for the growing season 1996. The carbon uptake was higher during the growing season 1997 due to a higher mean daily temperature, and a higher amount of incoming PAR. For bole respiration the maximum rate for both growing seasons amounted 3.6 µmol m-2 S-1. Integrated over the growing season the total bole respiration amounted 4.5 and 4.3 ton C ha-1 y-1 for respectively the growing season 1997 and 1996. At high temperatures and high PPFD, temperature becomes a limiting factor for Net Canopy Photosynthesis (NCP). A total forest canopy has, just as leaves, a curvilinear reaction on PPFD. This finding allowed to construct a one-layer or 'big leaf' model which simulated-the NCP as well as did the multi-layer FORUG model. However a multi-layer model for simulating the NCP is preffered as it allows more simpler incorporation or adaptation of parameters.

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