scholarly journals Effect of vapour pressure deficit on gas exchange of field-grown cotton

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Katrina J. BROUGHTON ◽  
Paxton PAYTON ◽  
Daniel K. Y. TAN ◽  
David T. TISSUE ◽  
Michael P. BANGE
Keyword(s):  
Vapour Pressure ◽  
Water Status ◽  
Vapour Pressure Deficit ◽  
Potential Effect ◽  
Yield Response ◽  
Individual Plant ◽  
Environment Interaction ◽  
Climate Change Research ◽  
Leaf Level ◽  
The Impact

Abstract Background Plants respond to changes in vapour pressure deficit (VPD) between the leaf and the atmosphere through changes in stomatal response, which can consequently affect transpiration, photosynthesis, and leaf-level water use efficiencies. With projected warmer air temperatures, changes in rainfall distribution and altered VPD in future climates, it is important to understand the potential effect of VPD on leaf-level physiology of field-grown crops. The aim of this study was to assess the impact of altered VPD on leaf-level physiology of field-grown cotton to improve the current understanding of the plant-by-environment interaction, thereby contributing to validation and improvement of physiological and yield response models. Different VPD environments in the field were generated by planting cotton on three dates within the sowing window (early-season (S1) = 5th October 2011; mid-season (S2) = 9th November 2011; and late-season (S3) = 30th November 2011). VPD was also modified by altering crop irrigations. Results VPDL accounted for the largest proportion of the explained variation in both stomatal conductance (32%∼39%) and photosynthetic (16%∼29%) responses of cotton. Generally, smaller percentages of variation were attributed to other main factors such as the individual plant (Plant), and accumulated temperature stress hours (ASH; a measure of plant water status over time) and interactive factors, including leaf vapour pressure deficit (VPDL) × Plant and Plant × ASH; however, a proportion of variation was unexplained. In addition, the Asat/E (instantaneous transpiration efficiency, ITE) model developed based on cotton grown in the glasshouse was applied to cotton grown in the field. We found that the modelled Asat/E and field-measured Asat/E were very similar, suggesting that the mechanistic basis for ITE was similar in both environments. Conclusions This study highlights the importance of accounting for VPD in climate change research, given that stomata are highly responsive to changes in VPD. This experiment provides a basis for physiology and production models, particularly in terms of cotton response to projected climatic environments.

Seasonal changes in the water status of three woody legumes from the Atlantic forest, Caratinga, Brazil

2000 ◽  
Vol 16 (1) ◽  
pp. 21-32 ◽  
Author(s):  
J. P. Lemos Filho ◽  
C. V. Mendonça Filho
Keyword(s):  
Atlantic Forest ◽  
Vapour Pressure ◽  
Seasonal Changes ◽  
Water Status ◽  
Linear Equations ◽  
Canopy Cover ◽  
Correlation Coefficients ◽  
Vapour Pressure Deficit ◽  
Strong Relationship ◽  
Woody Legumes

The Atlantic forest of Brazil is considered to be a high priority for conservation in South America. Despite its importance, few phenological and ecophysiological data are available for plants of this area. In this study the seasonal changes in the water potentials (Ψ) and the phenological behaviour of three woody legumes are related to environmental conditions, particularly air vapour pressure deficit (VPD). The values of Ψ at predawn were greater than −0.75 MPa for all species even during the dry season (May–September). The minimal daily value of Ψ was −3.8 MPa. The maximum daily amplitude of Ψ (Δ parameter) was correlated with the air vapour pressure deficit, showing high correlation coefficients in linear equations. A high recovery rate of Ψ after rain (greater than 0.80) was registered for all species, suggesting a high hydraulic conductivity. The high values of Ψ at predawn during the year and the strong relationship between the daily amplitude of Ψ and VPD suggested that the changes in the canopy cover are related more to atmospheric drought than to soil water deficit.

An assessment of potato sap flow as affected by soil water status, solar radiation and vapour pressure deficit

1999 ◽  
Vol 79 (2) ◽  
pp. 245-253 ◽  
Author(s):  
R. Gordon ◽  
D. M. Brown ◽  
A. Madani ◽  
M. A. Dixon
Keyword(s):  
Soil Water ◽  
Water Use ◽  
Vapour Pressure ◽  
Sap Flow ◽  
Water Status ◽  
Vapour Pressure Deficit ◽  
Potato Cultivars ◽  
Rapid Decline ◽  
Plant Variation ◽  
Flow Monitoring

Water-use of three field-grown potato cultivars (Atlantic, Monona and Norchip) was examined using a commercially available sap flow monitoring system over three consecutive growing seasons. The objectives of the investigation were to utilize the sap flow system to assess the water use of three field-grown potato cultivars. This included an assessment of the relationship between environmental conditions, water status and measured sap flow including the plant-to-plant variation in sap flow and an evaluation of relative transpiration in relation to the soil water status.Each cultivar maintained daily sap flow close to the atmospheric potential transpiration until approximately 70% of the available water was depleted. Under conditions where the soil was drier (>70% depleted), Monona potato plants exhibited a more rapid decline in transpiration than Norchip and Atlantic.Hourly sap flow rates were closely related to solar irradiance, especially under well-watered conditions, with no apparent light saturation point. Vapour pressure deficit effects on sap flow were less pronounced, although maximum vapour pressure deficits encountered were only 2 kPa. Key words: Water use, sap flow, transpiration, potato

Low vapour pressure deficits: Historical frequency and effect on tomato yield in southwestern Ontario

1998 ◽  
Vol 78 (3) ◽  
pp. 473-475
Author(s):  
A. Liptay ◽  
C. S. Tan ◽  
R. Ramsey ◽  
C. F. Drury ◽  
D. W. A. Hunt ◽  
...  
Keyword(s):  
Vapour Pressure ◽  
High Frequency ◽  
Lake Erie ◽  
Historical Analysis ◽  
Vapour Pressure Deficit ◽  
Yield Response ◽  
Growing Seasons ◽  
Tomato Yield ◽  
June July ◽  
A Site

An historical analysis of vapour pressure deficit was done to determine the frequency of very low vapour pressure deficits during June, July and August of the growing seasons, in Harrow, Ontario. The impetus for the analysis was a lack of yield response of processing tomatoes to fertigation in 1995 compared to other years or sites. In the historical analysis, 2 years, 1964 and 1995, were identified as having a high frequency of very low daily vapour pressure deficits during the growing season. The site of the experiment where low VPD was recorded was about 5 km north from the shore of Lake Erie. A site 27 km away from Harrow, and about 10 km north of Lake Erie, near Leamington, Ontario, had a normal, increased yield response to the fertigation treatment. Key words: Relative humidity, vapour pressure deficit, yield, tomato

scholarly journals Mechanisms linking plant productivity and water status for a temperate Eucalyptus forest flux site: analysis over wet and dry years with a simple model

2008 ◽  
Vol 35 (6) ◽  
pp. 493 ◽  
Author(s):  
David A. Pepper ◽  
Ross E. McMurtrie ◽  
Belinda E. Medlyn ◽  
Heather Keith ◽  
Derek Eamus
Keyword(s):  
Soil Moisture ◽  
Water Availability ◽  
Vapour Pressure ◽  
Water Status ◽  
Vapour Pressure Deficit ◽  
Co2 Flux ◽  
Lower Sensitivity ◽  
Forest Site ◽  
Eucalyptus Forest ◽  
Dry Conditions

A simple process-based model was applied to a tall Eucalyptus forest site over consecutive wet and dry years to examine the importance of different mechanisms linking productivity and water availability. Measured soil moisture, gas flux (CO2, H2O) and meteorological records for the site were used. Similar levels of simulated H2O flux in ‘wet’ and ‘dry’ years were achieved when water availability was not confined to the first 1.20 m of the soil profile, but was allowed to exceed it. Although the simulated effects of low soil and atmospheric water content on CO2 flux, presumably via reduction in stomatal aperture, also acted on transpiration, they were offset in the dry year by a higher vapour-pressure deficit. A sensitivity analysis identified the processes that were important in wet versus dry years, and on an intra-annual timeframe. Light-limited productivity dominated in both years, except for the driest period in the dry year. Vapour-pressure deficit affected productivity across more of each year than soil moisture, but both effects were larger in the dry year. The introduction of a reduced leaf area tended to decrease sensitivity in the dry year. Plant hydraulic architecture that increases plant available water, maximises productivity per unit water use and achieves lower sensitivity to low soil moisture levels should minimise production losses during dry conditions.

Assessing the impact of agro-climatic factors on pod filling of grass pea

2018 ◽  
Author(s):  
Argha Ghosh
Keyword(s):  
Vapour Pressure ◽  
Field Experiments ◽  
Climatic Factors ◽  
Vapour Pressure Deficit ◽  
Grass Pea ◽  
Positive Correlation ◽  
Temperature Range ◽  
Sowing Dates ◽  
Soil Temperatures ◽  
The Impact

Field experiments were conducted for two successive years with grass pea (cv. ‘Prateek’) sown on nine dates at weekly interval at Instructional Farm (22°58´ N, 88°31´ E), Bidhan Chandra Krishi Viswavidyalaya, West Bengal, India to investigate the impact of agroclimatic factors on pod filling of grass pea. Results showed that pod filling percentage (PFP) increased with delay in sowing dates, attaining the highest value (96.7 %) in crop sown on 30th November, beyond which it decreased gradually with further delay in sowing. Maximum and minimum temperatures, morning and afternoon soil temperatures, recorded at 5, 15 and 30 cm soil depths, morning and afternoon vapour pressure deficits at pre-flowering phase exhibited negative association and contrarily, when prevailing during reproductive and pod development phases, these parameters demonstrated positive correlation with PFP. Temperature range during reproductive phase increased with delay in sowing dates and it exhibited significant positive correlation with PFP. As demonstrated by stepwise regression analysis, Accumulated photothermal unit (APTU) prevailing at maturity phase alone accounted for 67.4 % of the total variation in PFP and together with temperature range it explained 91.3 % variation. APTU, temperature range, afternoon vapour pressure deficit and afternoon soil temperature seem to be the critical agroclimatic variables influencing the pod filling percentage significantly.

scholarly journals The dependence of water potential in shoots of <i>Picea abies</i> on air and soil water status

1998 ◽  
Vol 16 (4) ◽  
pp. 470-476 ◽  
Author(s):  
A. Sellin
Keyword(s):  
Picea Abies ◽  
Water Potential ◽  
Soil Water ◽  
Vapour Pressure ◽  
Water Status ◽  
Vapour Pressure Deficit ◽  
Plant Ecology ◽  
Evaporative Demand ◽  
Leaf Water Status ◽  
Water Losses

Abstract. Where there is sufficient water storage in the soil the water potential (Ψx) in shoots of Norway spruce [Picea abies (L.) Karst.] is strongly governed by the vapour pressure deficit of the atmosphere, while the mean minimum values of Ψx usually do not drop below –1.5 MPa under meteorological conditions in Estonia. If the base water potential (Ψb) is above –0.62 MPa, the principal factor causing water deficiency in shoots of P. abies may be either limited soil water reserves or atmospheric evaporative demand depending on the current level of the vapour pressure deficit. As the soil dries the stomatal control becomes more efficient in preventing water losses from the foliage, and the leaf water status, in turn, less sensitive to atmospheric demand. Under drought conditions, if Ψb falls below –0.62 MPa, the trees' water stress is mainly caused by low soil water availability. Further declines in the shoot water potential (below –1.5 MPa) can be attributed primarily to further decreases in the soil water, i.e. to the static water stress.Key words. Hydrology (evapotranspiration · plant ecology · soil moisture).

Vapour pressure deficit aids the interpretation of cotton canopy temperature response to water deficit

2014 ◽  
Vol 41 (5) ◽  
pp. 535 ◽  
Author(s):  
Warren C. Conaty ◽  
James R. Mahan ◽  
James E. Neilsen ◽  
Greg A. Constable
Keyword(s):  
Water Stress ◽  
Soil Water ◽  
Vapour Pressure ◽  
Water Status ◽  
Canopy Temperature ◽  
Vapour Pressure Deficit ◽  
Irrigation Scheduling ◽  
Plant Water ◽  
Stress Detection ◽  
Water Fraction

Crop canopy temperature (Tc) is coupled with transpiration, which is a function of soil and atmospheric conditions and plant water status. Thus, Tc has been identified as a real-time, plant-based tool for crop water stress detection. Such plant-based methods theoretically integrate the water status of both the plant and its environment. However, previous studies have highlighted the limitations and difficulty of interpreting the Tc response to plant and soil water stress. This study investigates the links between cotton Tc, established measures of plant water relations and atmospheric vapour pressure deficit (VPDa). Concurrent measures of carbon assimilation (A), stomatal conductance (gs), leaf water potential (Ψl), soil water (fraction of transpirable soil water (FTSW)) and Tc were conducted in surface drip irrigated cotton over two growing seasons. Associations between A, gs, Ψl, FTSW and Tc are presented, which are significantly improved with the inclusion of VPDa. It was concluded that utilising the strong associations between Ψl, VPDa and Tc, an adjustment of 1.8°C for each unit of VPDa should be made to the critical Tc for irrigation. This will improve the precision of irrigation in Tc based irrigation scheduling protocols. Improved accuracy in water stress detection with Tc, and an understanding of the interaction the environment plays in this response, can potentially improve the efficiency of irrigation.

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