Towards a spatial understanding of water use of several land-cover classes: an examination of relationships amongst pre-dawn leaf water potential, vegetation water use, aridity and MODIS LAI

Ecohydrology ◽  
2009 ◽  
pp. n/a-n/a ◽  
Author(s):  
Anthony R. Palmer ◽  
Sigfredo Fuentes ◽  
Daniel Taylor ◽  
Cate Macinnis-Ng ◽  
Melanie Zeppel ◽  
...  
Keyword(s):  
Land Cover ◽  
Water Potential ◽  
Water Use ◽  
Leaf Water Potential ◽  
Leaf Water ◽  
Potential Vegetation ◽  
Spatial Understanding ◽  
Vegetation Water ◽  
Modis Lai

THE WATER RELATIONS AND IRRIGATION REQUIREMENTS OF COCONUT (Cocos nucifera): A REVIEW

2011 ◽  
Vol 47 (1) ◽  
pp. 27-51 ◽  
Author(s):  
M. K. V. CARR
Keyword(s):  
Water Potential ◽  
Water Use ◽  
Water Relations ◽  
Leaf Water Potential ◽  
Water Productivity ◽  
Chloride Ions ◽  
Leaf Water ◽  
Flower Initiation ◽  
Plant Water ◽  
Drought Mitigation

SUMMARYThe results of research on the water relations and irrigation needs of coconut are collated and summarized in an attempt to link fundamental studies on crop physiology to drought mitigation and irrigation practices. Background information on the centres of origin and production of coconut and on crop development processes is followed by reviews of plant water relations, crop water use and water productivity, including drought mitigation. The majority of the recent research published in the international literature has been conducted in Brazil, Kerala (South India) and Sri Lanka, and by CIRAD (France) in association with local research organizations in a number of countries, including the Ivory Coast. The unique vegetative structure of the palm (stem and leaves) together with the long interval between flower initiation and the harvesting of the mature fruit (44 months) mean that causal links between environmental factors (especially water) are difficult to establish. The stomata play an important role in controlling water loss, whilst the leaf water potential is a sensitive indicator of plant water status. Both stomatal conductance and leaf water potential are negatively correlated with the saturation deficit of the air. Although roots extend to depths >2 m and laterally >3 m, the density of roots is greatest in the top 0–1.0 m soil, and laterally within 1.0–1.5 m of the trunk. In general, dwarf cultivars are more susceptible to drought than tall ones. Methods of screening for drought tolerance based on physiological traits have been proposed. The best estimates of the actual water use (ETc) of mature palms indicate representative rates of about 3 mm d−1. Reported values for the crop coefficient (Kc) are variable but suggest that 0.7 is a reasonable estimate. Although the sensitivity of coconut to drought is well recognized, there is a limited amount of reliable data on actual yield responses to irrigation although annual yield increases (50%) of 20–40 nuts palm−1 (4–12 kg copra, cultivar dependent) have been reported. These are only realized in the third and subsequent years after the introduction of irrigation applied at a rate equivalent to about 2 mm d−1 (or 100 l palm−1 d−1) at intervals of up to one week. Irrigation increases female flower production and reduces premature nut fall. Basin irrigation, micro-sprinklers and drip irrigation are all suitable methods of applying water. Recommended methods of drought mitigation include the burial of husks in trenches adjacent to the plant, mulching and the application of common salt (chloride ions). An international approach to addressing the need for more information on water productivity is recommended.

scholarly journals The importance of cuticular permeance in assessing plant water–use strategies

2020 ◽  
Vol 40 (4) ◽  
pp. 425-432
Author(s):  
Matthew Lanning ◽  
Lixin Wang ◽  
Kimberly A Novick
Keyword(s):  
Water Stress ◽  
Water Potential ◽  
Water Use ◽  
Leaf Water Potential ◽  
Stress Responses ◽  
Leaf Water ◽  
Plant Water ◽  
Stomatal Control ◽  
Plant Water Use ◽  
The Impact

Abstract Accurate understanding of plant responses to water stress is increasingly important for quantification of ecosystem carbon and water cycling under future climates. Plant water-use strategies can be characterized across a spectrum of water stress responses, from tight stomatal control (isohydric) to distinctly less stomatal control (anisohydric). A recent and popular classification method of plant water-use strategies utilizes the regression slope of predawn and midday leaf water potentials, σ, to reflect the coupling of soil water availability (predawn leaf water potential) and stomatal dynamics (daily decline in leaf water potential). This type of classification is important in predicting ecosystem drought response and resiliency. However, it fails to explain the relative stomatal responses to drought of Acer sacharrum and Quercus alba, improperly ranking them on the spectrum of isohydricity. We argue this inconsistency may be in part due to the cuticular conductance of different species. We used empirical and modeling evidence to show that plants with more permeable cuticles are more often classified as anisohydric; the σ values of those species were very well correlated with measured cuticular permeance. Furthermore, we found that midday leaf water potential in species with more permeable cuticles would continue to decrease as soils become drier, but not in those with less permeable cuticles. We devised a diagnostic parameter, Γ, to identify circumstances where the impact of cuticular conductance could cause species misclassification. The results suggest that cuticular conductance needs to be considered to better understand plant water-use strategies and to accurately predict forest responses to water stress under future climate scenarios.

The combined effects of phosphorus and zinc on evapotranspiration, leaf water potential, water use efficiency and tuber attributes of potato under water deficit conditions

2013 ◽  
Vol 162 ◽  
pp. 31-38 ◽  
Author(s):  
R. Motalebifard ◽  
N. Najafi ◽  
S. Oustan ◽  
M.R. Nyshabouri ◽  
M. Valizadeh
Keyword(s):  
Water Use Efficiency ◽  
Water Potential ◽  
Water Deficit ◽  
Water Use ◽  
Leaf Water Potential ◽  
Leaf Water ◽  
Combined Effects ◽  
Use Efficiency

scholarly journals Impact of Kaolin Particle Film and Water Deficit on Wine Grape Water Use Efficiency and Plant Water Relations

HortScience ◽  
2010 ◽  
Vol 45 (8) ◽  
pp. 1178-1187 ◽  
Author(s):  
D. Michael Glenn ◽  
Nicola Cooley ◽  
Rob Walker ◽  
Peter Clingeleffer ◽  
Krista Shellie
Keyword(s):  
Water Use Efficiency ◽  
Water Potential ◽  
Water Use ◽  
Leaf Water Potential ◽  
Stomatal Closure ◽  
Canopy Temperature ◽  
Leaf Water ◽  
Film Treatment ◽  
Use Efficiency ◽  
Moisture Conditions

Water use efficiency (WUE) and response of grape vines (Vitis vinifera L. cvs. ‘Cabernet Sauvignon’, ‘Merlot’, and ‘Viognier’) to a particle film treatment (PFT) under varying levels of applied water were evaluated in Victoria, Australia, and southwestern Idaho. Vines that received the least amount of water had the warmest canopy or leaf surface temperature and the lowest (more negative) leaf water potential, stomatal conductance (gS), transpiration (E), and photosynthesis (A). Vines with plus-PFT had cooler leaf and canopy temperature than non-PFT vines; however, temperature difference resulting from irrigation was greater than that resulting from PFT. In well-watered vines, particle film application increased leaf water potential and lowered gS. Point-in-time measurements of WUE (A/E) and gS did not consistently correspond with seasonal estimates of WUE based on carbon isotope discrimination of leaf or shoot tissue. The response of vines with particle film to undergo stomatal closure and increase leaf water potential conserved water and enhanced WUE under non-limiting soil moisture conditions and the magnitude of response differed according to cultivar.

Water uptake depth is coordinated with leaf water potential, water‐use efficiency and drought vulnerability in karst vegetation

2020 ◽  
Vol 229 (3) ◽  
pp. 1339-1353
Author(s):  
Yali Ding ◽  
Yunpeng Nie ◽  
Hongsong Chen ◽  
Kelin Wang ◽  
José I. Querejeta
Keyword(s):  
Water Use Efficiency ◽  
Water Potential ◽  
Water Use ◽  
Water Uptake ◽  
Leaf Water Potential ◽  
Leaf Water ◽  
Drought Vulnerability ◽  
Use Efficiency

Vertical Wilting and Photosynthesis, Transpiration, and Water Use Efficiency of Sunflower Leaves

1979 ◽  
Vol 6 (1) ◽  
pp. 109 ◽  
Author(s):  
HM Rawson
Keyword(s):  
Water Use Efficiency ◽  
Water Potential ◽  
Water Use ◽  
Leaf Water Potential ◽  
Stomatal Closure ◽  
Net Photosynthesis ◽  
Leaf Water ◽  
Vertical Orientation ◽  
Use Efficiency ◽  
Node Position

Plants of two sunflower cultivars were exposed to a number of soil drying cycles and the gas exchange of young, fully expanded leaves at different nodes was measured continuously from when the leaves were turgid until when they were severely and vertically wilted. Peak rates of net photosynthesis increased with the height of leaf insertion but, regardless of node position, leaves at vertical wilting always had rates of net photosynthesis which were close to 50% of peak rates. Although the leaf water potential at which vertical wilting occurred ranged between - 1.3 and -2.2 MPa and varied even for a particular leaf position, there was a similar relationship between the rate of reduction in photosynthesis and the reduction in leaf water potential. No evidence was found for a threshold leaf water potential at which stomatal closure occurs. Water use efficiency improved when leaves changed from a horizontal to a vertical orientation, apparently through changes in leaf temperature but. by the stage of wilting, water use efficiency had already markedly improved over efficiencies of turgid leaves. Much of this improvement stemmed from changes in leaf conductances. No clear differences between cultivars were evident in any parameter measured. The likely effects that wilting will have on water use efficiency in the field and strategies for optimising water use on a diurnal basis are discussed.

scholarly journals Rootstock Genotypes Shape the Response of cv. Pinot gris to Water Deficit

Agronomy ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 75
Author(s):  
Michele Faralli ◽  
Pier Lugi Bianchedi ◽  
Massimo Bertamini ◽  
Claudio Varotto
Keyword(s):  
Water Stress ◽  
Water Potential ◽  
Leaf Area ◽  
Water Use ◽  
Leaf Water Potential ◽  
Water Availability ◽  
Leaf Water ◽  
Daily Water ◽  
Shallow Soils ◽  
Reduced Water

Understanding the physiological basis underlying the water stress responses in grapevine is becoming increasingly topical owing to the challenges that climate change will impose to grapevine agriculture. Here we used cv. Pinot gris (clone H1), grafted on a series of tolerant (1103Paulsen; P), sensitive (SO4) and recently selected (Georgikon28; G28, Georgikon121; G121, Zamor17; Z17) rootstocks. Plants were either subjected to reduced water availability (WS) or maintained at pot capacity (WW). Photosynthetic (light response curves), stomatal and in vivo gas exchange analysis were carried out as well as dynamics of daily water use (WU), leaf area accumulation with affordable RGB imaging pipelines and leaf water potential. Significant genotypic variation was recorded between rootstocks for most of the traits analyzed under optimal conditions with P and SO4 showing a more vigorous growth, higher CO2 assimilation rate, stomatal conductance and stomatal density per unit of leaf area than G28, G121, Z17 (p < 0.001). Under WS, rootstocks induced different water stress response in Pinot gris, with G28 and G121 showing a higher sensitivity of water use to reduced water availability (WS) (p = 0.021) and no variation for midday leaf water potential until severe WS. P, Z17 and to some extent SO4 induced a pronounced near-anisohydric response with a general WU maintenance followed by reduction in leaf water potential even at high levels of soil water content. In addition, G28 and G121 showed a less marked slope in the linear relationship between daily water use and VPD (p = 0.008) suggesting elevated sensitivity of transpiration to evaporative demand. This led to an insensitivity for total dry weight biomass of G28 and G121 under WS conditions (p < 0.001). This work provides: (i) an in-depth analysis for a series of preferable traits under WS in Pinot gris; (ii) a characterization of Pinot gris × rootstock interaction and a series of desirable traits under WS induced by several rootstocks; (iii) the potential benefit for the use a series of affordable methods (e.g., RGB imaging) to easily detect dynamic changes in biomass in grapevine and quickly phenotype genotypes with superior responses under WS. In conclusion, the near-isohydric and conservative behavior observed for G28 and G121 coupled with their low vigor suggest them as potential Pinot gris rootstock candidates for sustaining grapevine productivity in shallow soils likely to develop terminal stress conditions.

Agronomic and Physiological Responses of Soybean and Sorghum Crops to Water Deficits. IV. Photosynthesis, Transpiration and Water Use Efficiency in Leaves

1978 ◽  
Vol 5 (2) ◽  
pp. 195 ◽  
Author(s):  
HM Rawson ◽  
NC Turner ◽  
JE Begg
Keyword(s):  
Water Use Efficiency ◽  
Water Potential ◽  
Water Use ◽  
Leaf Water Potential ◽  
Flag Leaf ◽  
Grain Filling ◽  
Leaf Water ◽  
Water Deficits ◽  
Use Efficiency ◽  
Soybean Leaves

Detailed diurnal measurements of photosynthesis, transpiration and water use efficiency of leaves of sorghum and soybean were made during the reproductive growth of field plants. Photosynthesis was measured mainly by infrared gas techniques. The indication in well watered plants was that diurnal net carbon fixation per unit area of sorghum leaves was some 2.3 times greater than that of comparably illuminated soybean leaves while concurrent transpiration losses were less. Simple carbon budgets for the two crops over 24 h suggested that the assimilation by a leaf area equivalent to that of the flag leaf was required solely to sustain respiration by the sorghum head during mid- grain filling, while approximately 5 cm� of leaf was required to sustain respiration of each soybean pod. The comparisons made on a diurnal basis between plants of soybean exposed to different water deficits during grain filling demonstrated the increasing importance of early morning and late afternoon photosynthesis as water became less available. They also showed the rapidity with which plants can recover from stress once water is supplied. It is calculated that, for continuously clear conditions, as daily minimum leaf water potential fell from - 1 .5 to - 2.5 MPa, the integrated daily assimilation by leaves was reduced by about 9 % for every 0.1 MPa change; soybean leaves were not measured at leaf water potentials much below - 2.6 MPa. A ratio between gas phase and residual resistances remained relatively stable over the range of leaf water potential measured. However, the water use efficiency of single leaves was reduced with increasing soil water deficits because of changes in leaf temperature and leaf-to-air vapour pressure differences.

Effects of No-tillage and Ploughing on Efficiency of Water Use in Maize and Cowpea

1978 ◽  
Vol 14 (2) ◽  
pp. 113-119 ◽  
Author(s):  
R. Lal ◽  
P. R. Maurya ◽  
S. Osei-Yeboah
Keyword(s):  
Zea Mays ◽  
Water Use Efficiency ◽  
Water Potential ◽  
Water Use ◽  
Leaf Water Potential ◽  
Vigna Unguiculata ◽  
Sprinkler System ◽  
Leaf Water ◽  
No Tillage ◽  
Use Efficiency

SUMMARYWater use efficiency of maize (Zea mays) and cowpea (Vigna unguiculata) was investigated, with and without tillage, under four irrigation frequencies in which 12 mm of water was applied at 2, 4, 8 and 12 day intervals, using a sprinkler system. Both maize and cowpea under no-tillage yielded more than with conventional ploughing. Water use efficiency of maize without tillage was 18·3, 17·5, 57·8 and 100% greater than with tillage at irrigation frequencies of 2, 4, 8 and 12 days respectively. Whereas the leaf water potential of cowpea was not affected by tillage, that of maize was generally higher for no-tillage compared with conventional ploughing.

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