The Effect of Water Shortage on Potted Peach Trees in Relation to Ecophysiological Parameters and Infra-red Thermometry

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 541b-541
Author(s):  
Rita Giuliani ◽  
James A. Flore
Keyword(s):  
Chlorophyll Fluorescence ◽  
Gas Exchange ◽  
Early Detection ◽  
Water Potential ◽  
Canopy Temperature ◽  
Water Shortage ◽  
Development Rate ◽  
Plant Water ◽  
Infra Red ◽  
Peach Trees

Potted peach trees grown outdoors during the 1997 season were subjected to drought and subsequent rewatering to evaluate their dynamic response to soil water content. The investigation was primarily focused on the early detection of plant water stress to prevent negative effects on the growth. Leaf chlorophyll fluorescence and canopy temperature estimates (by infra-red thermometry) were conducted. Drought effect on physiological processes were detected through by estimates of canopy development rate, leaf gas-exchange measurements; while leaf water potential was measured to characterize plant water status. A decrease in the canopy's development rate was found 1 week after irrigation was stopped, which also coincided with a more-negative leaf water potential, whereas a decrease of the gas-exchange activities occurred several days later. No significant differences between the stressed and control plants were recorded by the chlorophyll fluorescence parameters (Fo, Fm, Fv and the ratio Fv/Fm), whereas the infra-red estimates of canopy temperature detected a slight increase of the canopy surface temperature (connected to the change of leaf energy balance and in relation to partial stomatal closure) on the non-irrigated plants 1 week after the beginning of the trial. The use of infra-red thermometry for early detection of water shortage is discussed.

scholarly journals Microtensiometers Accurately Measure Stem Water Potential in Woody Perennials

Plants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2780
Author(s):  
Victor Blanco ◽  
Lee Kalcsits
Keyword(s):  
Water Potential ◽  
Leaf Gas Exchange ◽  
Water Status ◽  
Full Range ◽  
Canopy Temperature ◽  
Plant Water ◽  
Stem Water Potential ◽  
Woody Tissue ◽  
Woody Perennials ◽  
Stem Water

Stem water potential (Ψstem) is considered to be the standard measure of plant water status. However, it is measured with the pressure chamber (PC), an equipment that can neither provide continuous information nor be automated, limiting its use. Recent developments of microtensiometers (MT; FloraPulse sensors), which can continuously measure water tension in woody tissue of the trunk of the tree, can potentially highlight the dynamic nature of plant water relations. Thus, this study aimed to validate and assess the usefulness of the MT by comparing the Ψstem provided by MT with those same measurements from the PC. Here, two irrigation treatments (a control and a deficit treatment) were applied in a pear (Pyrus communis L.) orchard in Washington State (USA) to capture the full range of water potentials in this environment. Discrete measurements of leaf gas exchange, canopy temperature and Ψstem measured with PC and MT were made every two hours for four days from dawn to sunset. There were strong linear relationships between the Ψstem-MT and Ψstem-PC (R2 > 0.8) and with vapor pressure deficit (R2 > 0.7). However, Ψstem-MT was more variable and lower than Ψstem-PC when Ψstem-MT was below −1.5 MPa, especially during the evening. Minimum Ψstem-MT occurred later in the afternoon compared to Ψstem-PC. Ψstem showed similar sensitivity and coefficients of variation for both PC and MT acquired data. Overall, the promising results achieved indicated the potential for MT to be used to continuously assess tree water status.

scholarly journals Leaf Water Relations in Lime Trees Grown under Shade Netting and Open-Air

Plants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 510 ◽  
Author(s):  
Ana Belén Mira-García ◽  
Wenceslao Conejero ◽  
Juan Vera ◽  
María Carmen Ruiz-Sánchez
Keyword(s):  
Gas Exchange ◽  
Leaf Gas Exchange ◽  
Water Status ◽  
Canopy Temperature ◽  
Net Photosynthesis ◽  
Irrigation Scheduling ◽  
Plant Water Status ◽  
Plant Water ◽  
Stem Water Potential ◽  
Thermal Index

Physiological plant water status indicators are useful for managing precision irrigation in regions with limited water resources. The aim of this work was to evaluate the effect of shade netting on the diurnal and seasonal variations of several plant water status indicators in young lime trees (Citrus latifolia Tan., cv. Bearss), grown at the CEBAS-CSIC experimental station in Murcia, Spain. Stem water potential (Ψstem), leaf gas exchange (net photosynthesis (Pn) and stomatal conductance (gs)), and canopy temperature (Tc) were measured on representative days of winter and summer. The Ψstem daily pattern was quite similar in both seasons under both conditions. However, the circadian rhythm of leaf gas exchange was affected by shade conditions, especially in summer, when shaded leaves showed maximum gs values for a longer time, allowing higher net photosynthesis (37%). Canopy temperature behaved similarly in both conditions, nevertheless, lower values were recorded in open-air than in shaded trees in the two seasons. The canopy-to-air temperature difference (Tc − Ta), however, was lower in shaded trees during the daylight hours, indicating the higher degree of leaf cooling that was facilitated by high gs values. The possibility of continuously recording Tc makes it (or the proposed canopy thermal index, CTI) a promising index for precise irrigation scheduling. Shade netting was seen to favour gas exchange, suggesting that it may be considered alternative to open-air for use in semi-arid areas threatened by climate change.

Responses of functional traits to seven-year nitrogen addition in two tree species: coordination of hydraulics, gas exchange and carbon reserves

2020 ◽  
Author(s):  
Hongxia Zhang ◽  
Fenghui Yuan ◽  
Jiabing Wu ◽  
Changjie Jin ◽  
Alexandria L Pivovaroff ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Water Potential ◽  
Functional Traits ◽  
Tree Species ◽  
Soluble Sugars ◽  
Vessel Diameter ◽  
N Deposition ◽  
Plant Water ◽  
N Addition

Abstract Atmospheric nitrogen (N) deposition has been observed to impact plant structure and functional traits in terrestrial ecosystems. Although the effect of N deposition on plant water use has been well-evaluated in laboratories and in experimental forests, the linkages between water and carbon relations under N deposition are unclear. Here, we report on hydraulics, gas exchange and carbon reserves of two broad-leaved tree species (Quercus mongolica and Fraxinus mandshurica) in mature temperate forests after a seven-year experiment with different levels of N addition (control (CK), low (23 kg N ha−1 yr−1), medium (46 kg N ha−1 yr−1) and high (69 kg N ha−1 yr−1)). We investigated variation in hydraulic traits (xylem-specific hydraulic conductivity (Ks), native percentage loss of conductivity (PLC) and leaf water potential), xylem anatomy (vessel diameter and density), gas exchange (maximum net photosynthesis rate and stomatal conductance) and carbon reserves (soluble sugars, starch and total nonstructural carbohydrates (NSC)) with different N addition levels. We found that medium N addition significantly increased Ks and vessel diameter compared to control, but accompanied increasing PLC and decreasing leaf water potential, suggesting that N addition results in a greater hydraulic efficiency and higher risk of embolism. N addition promoted photosynthetic capacity via increasing foliar N concentration but did not change stomatal conductance. In addition, we found increase in foliar soluble sugar concentration and decrease in starch concentration with N addition, and positive correlations between hydraulic traits (vessel diameter and PLC) and soluble sugars. These coupled responses of tree hydraulics and carbon metabolism are consistent with a regulatory role of carbohydrates in maintaining hydraulic integrity. Our study provides an important insight into the relationship of plant water transport and carbon dynamics under increasing N deposition.

Diurnal Changes in Plant Water Potential and Canopy Temperature of Wheat as Affected by Drought 1

1978 ◽  
Vol 70 (6) ◽  
pp. 999-1004 ◽  
Author(s):  
W. L. Ehrler ◽  
S. B. Idso ◽  
R. D. Jackson ◽  
R. J. Reginato
Keyword(s):  
Water Potential ◽  
Canopy Temperature ◽  
Diurnal Changes ◽  
Plant Water ◽  
Plant Water Potential

scholarly journals 534 Use of Infrared Thermal Imagery for Ground-based and Real-time Detection of Water Deficit in Fruit Trees

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 487D-487
Author(s):  
Rita Giuliani ◽  
James A. Flore
Keyword(s):  
Real Time ◽  
Water Deficit ◽  
Early Recognition ◽  
Canopy Temperature ◽  
Fruit Trees ◽  
Water Shortage ◽  
Plant Water ◽  
Thermal Imagery ◽  
Thermal Signal ◽  
Plant Water Deficit

Ground-based infrared thermal imagery was applied for early detection of plant water deficit, i.e., before photosynthetic activity is depressed and before growth processes are negatively affected by water shortage. Remote and real-time sensing of radiative canopy surface temperature was performed in Michigan in Summer 1999 on peach and apple orchards, using a digital IR imaging radiometer. Still images and videos were acquired on single canopies of well-watered plants and plants subjected to water depletion. Atmospheric parameters were monitored simultaneously. On apple trees, the apparent canopy temperature showed a wider thermal dispersion [10 °C], compared to peach tree canopies [2–5 °C]. Central tendency and shape parameters describing the canopy thermal distribution could identify, even for apple canopies, the thermal signal [1–2 °C] of plant water deficit, before changes in leaf net photosynthetic rate and fruit diameter were observed. The results of this study support the application of digital infrared thermal imagery and image processing for early recognition of plant water deficit. The decrease of the cost of available thermographic cameras makes their use feasible.

Wheat Canopy Temperature: Relation to Plant Water Potential 1

1978 ◽  
Vol 70 (2) ◽  
pp. 251-256 ◽  
Author(s):  
W. L. Ehrler ◽  
S. B. Idso ◽  
R. D. Jackson ◽  
R. J. Reginato
Keyword(s):  
Water Potential ◽  
Canopy Temperature ◽  
Plant Water ◽  
Temperature Relation ◽  
Plant Water Potential
Sign in / Sign up

Export Citation Format

Share Document