Simultaneous recording of diurnal changes in leaf turgor pressure and stem water status of bread wheat reveal variation in hydraulic mechanisms in response to drought

Information about water relations within crop canopies is needed to improve our understanding of canopy resource distribution and crop productivity. In this study, we examined the dehydration/rehydration kinetics of different organs of wheat plants using ZIM-probes that continuously monitor water status non-destructively. ZIM-probes were clamped to the flag leaf and penultimate leaf of the same stem to monitor changes in turgor pressure, and a novel stem probe was clamped to the peduncle (just below the spike of the same stem) to monitor changes in stem water status. All organs behaved similarly under well-watered conditions, dehydrating and recovering at the same times of day. When water was withheld, the behaviour diverged, with the leaves showing gradual dehydration and incomplete recovery in leaf turgor pressure during the night, but the stem was affected to a lesser extent. Penultimate leaves were the most severely affected, reaching turgor loss point before the flag leaf. Upon rewatering, turgor pressure recovered but the output patch-pressure of the probes (Pp) oscillated at ~30 min periods in all organs of most plants (n = 4). Oscillations in Pp were attributed to oscillations in stomatal opening and appear to only occur above a threshold light intensity. The mechanisms identified in this study will be beneficial for crop productivity because the flag leaf is the source of most photoassimilates in developing grains, so the plant’s ability to maintain flag leaf hydration at the expense of older leaves should moderate the impact of drought on yield. Stomatal oscillations could increase water use efficiency as the plant attempts to rehydrate after drought.

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Effect of Water Regime and Nitrogen Fertilisation on Growth Dynamics, Water Status and Yield of Burley Tobacco (Nicotianatabacum L.)

Beiträge zur Tabakforschung International/Contributions to Tobacco Research ◽

10.2478/cttr-2013-0784 ◽

2004 ◽

Vol 21 (4) ◽

pp. 223-233

Author(s):

C Ruggiero ◽

G Angelino ◽

S Ascione ◽

A Napolitano

Keyword(s):

Plant Growth ◽

Nitrogen Fertilization ◽

Dry Matter ◽

Water Status ◽

Turgor Pressure ◽

Plant Water Status ◽

Plant Water ◽

Nitrogen Fertilisation ◽

Burley Tobacco ◽

Use Efficiency

AbstractThe results of a two-year research project into burley tobacco are reported and discussed. Three irrigation levels (40, 80 and 120% restitution of evapotranspiration (ET)) were factorially combined with four levels of nitrogen fertilisation (0, 80, 160 and 240 kg ha). Leaf area, leaf and stem dry matter and root development were measured. We monitored the water status of the 0-90 cm soil layer, the plants and stomatal resistance. Relations were also studied between leaf turgor pressure and plant growth, between the irrigation regime and plant water status, and between root and shoot development. Finally, water use efficiency (WUE) and quality and quantity of cured leaves yields were evaluated. Nitrogen fertilisation did not affect plant water status, although it promoted plant growth, both in terms of leaf area and leaf and stem dry matter, and induced a yield increase in quantity and quality. Our trial showed little interaction between nitrogen fertilization level and water regime. Under such agronomic condition, the margins for increasing plant growth with nitrogen fertilization are limited, which is why application of nitrogen rates in excess of 160 kg haappear inadvisable. The difference in irrigation volumes led to a different soil water content which affected plant water status, stomatal functioning, plant growth, both in the roots and shoots, yield and quality of the cured leaves. The latter did not vary with the increase in water volume, while yield increased. Water use efficiency increased as the irrigation volume decreased and varied during the cropping cycle, increasing until early bloom, then decreasing. Relations between leaf turgor pressure and plant growth highlighted the different response of plants subjected to water stress compared with non-stressed plants.

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Partial rootzone drying improves almond tree leaf-level water use efficiency and afternoon water status compared with regulated deficit irrigation

Functional Plant Biology ◽

10.1071/fp10247 ◽

2011 ◽

Vol 38 (5) ◽

pp. 372 ◽

Cited By ~ 24

Author(s):

Gregorio Egea ◽

Ian C. Dodd ◽

María M. González-Real ◽

Rafael Domingo ◽

Alain Baille

Keyword(s):

Gas Exchange ◽

Water Potential ◽

Leaf Gas Exchange ◽

Water Status ◽

Stem Water Potential ◽

Regulated Deficit Irrigation ◽

Leaf Level ◽

Use Efficiency ◽

Stem Water ◽

Partial Rootzone Drying

To determine whether partial rootzone drying (PRD) optimised leaf gas exchange and soil–plant water relations in almond (Prunus dulcis (Mill.) D.A. Webb) compared with regulated deficit irrigation (RDI), a 2 year trial was conducted on field-grown trees in a semiarid climate. Five irrigation treatments were established: full irrigation (FI) where the trees were irrigated at 100% of the standard crop evapotranspiration (ETc); three PRD treatments (PRD70, PRD50 and PRD30) that applied 70, 50 and 30% ETc, respectively; and a commercially practiced RDI treatment that applied 50% ETc during the kernel-filling stage and 100% ETc during the remainder of the growth season. Measurements of volumetric soil moisture content in the soil profile (0–100 cm), predawn leaf water potential (Ψpd), midday stem water potential (Ψms), midday leaf gas exchange and trunk diameter fluctuations (TDF) were made during two growing seasons. The diurnal patterns of leaf gas exchange and stem water potential (Ψs) were appraised during the kernel-filling stage in all irrigation regimes. When tree water relations were assessed at solar noon, PRD did not show differences in either leaf gas exchange or tree water status compared with RDI. At similar average soil moisture status (adjudged by similar Ψpd), PRD50 trees had higher water status than RDI trees in the afternoon, as confirmed by Ψs and TDF. Although irrigation placement showed no effects on diurnal stomatal regulation, diurnal leaf net photosynthesis (Al) was substantially less limited in PRD50 than in RDI trees, indicating that PRD improved leaf-level water use efficiency.

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Does predawn water potential discern between irrigation treatments in Galician white grapevine cultivars?

OENO One ◽

10.20870/oeno-one.2014.48.2.1566 ◽

2014 ◽

Vol 48 (2) ◽

pp. 123 ◽

Cited By ~ 3

Author(s):

José Manuel Mirás-Avalos ◽

Emiliano Trigo-Córdoba ◽

Yolanda Bouzas-Cid

Keyword(s):

Water Potential ◽

Leaf Water Potential ◽

Water Status ◽

Irrigation Management ◽

Growing Season ◽

Climatic Conditions ◽

Leaf Water ◽

Diurnal Changes ◽

Stem Water Potential ◽

Stem Water

Aims: To evaluate the usefulness of predawn water potential (Ψpd) to assess the water status of Galician grapevine cultivars for irrigation purposes.Methods and results: Three Galician white grapevine cultivars (Albariño, Godello and Treixadura) were subjected to rain-fed and irrigation conditions during the 2013 growing season. Diurnal changes in leaf water potential (Ψl) were measured using a pressure chamber on days with high evapotranspiration demand. Stem water potential (Ψs) was measured at midday. Ψpd was not able to discriminate between treatments, whereas Ψl and Ψs at midday were able to detect significant differences in water status among plants.Conclusion: Ψpd was not useful to evaluate vine water status under the Galician climatic conditions. In contrast, both Ψl and Ψs were effective for detecting differences between treatments and can thus be used for irrigation management purposes.Significance and impact of the study: This is the first study evaluating water status of Galician grapevine cultivars. It also provides useful information about the strategy for its control through measurements of midday Ψl or Ψs.

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Responses of Mungbean to Water Deficit, Water use Efficiency and Drought Resistance

Legume Research - An International Journal ◽

10.18805/lr-4344 ◽

2021 ◽

Author(s):

B. Sajitha ◽

R. Karthiyayini ◽

Samundeeswari .

Keyword(s):

Drought Stress ◽

Mung Bean ◽

Water Status ◽

Nitrate Assimilation ◽

Water Relation ◽

Cellular Level ◽

Protective Mechanism ◽

Agricultural Crop ◽

Use Efficiency ◽

The Impact

Backround: Legumes are the second important agricultural crop of great prominence to humans. Among 20000 legume species the mungbean is one of the most important grain cultivated in India. Drought is a major environmental stress that affects mungbean in the sub-humid, dry and intermediate zones of India. The present study records the response of mung bean varieties to water stress during its growth stage.Methods: The impact of drought stress imposed on the crop was evaluated by measuring the water relation parameters and the biochemical progresses like osmolyte accumulation, nitrate assimilation and antioxidant system in Mung bean during 2017-2018 in Avinashilingam Institute for Home Science and Higher Education for Women, Coimbatore.Result: Drought stress altered the water status of the crop by reducing the RWC, which was enhanced in drought susceptible varieties. Increased amount of proline denotes the osmoregulatory mechanism in the crop to bring about resistance and the elevated levels of antioxidant enzymes shows the protective mechanism in the crop at cellular level.

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Acidified Biochar as a Soil Amendment to Drought Stressed (Vicia faba L.) Plants: Influences on Growth and Productivity, Nutrient Status, and Water Use Efficiency

Agronomy ◽

10.3390/agronomy11071290 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1290

Author(s):

Taia A. Abd El-Mageed ◽

Eman E. Belal ◽

Mohamed O. A. Rady ◽

Shimaa A. Abd El-Mageed ◽

Elsayed Mansour ◽

...

Keyword(s):

Water Use Efficiency ◽

Soil Properties ◽

Water Use ◽

Seed Yield ◽

Soil Amendment ◽

Field Experiments ◽

Water Status ◽

Water Productivity ◽

Crop Productivity ◽

Use Efficiency

Drought is one of the major threats to global food security. Biochar use in agriculture has received much attention and improving it through chemical modification offers a potential approach for enhancing crop productivity. There is still limited knowledge on how acidified biochar influences soil properties, and consequently its influences on the agricultural productivity of drought stressed plants. The water use efficiency (I-WUE) of drought stressed faba beans was investigated through the effects of acidified biochar (ACBio) (a 3:100 (w:w) combination of citric acid and biochar) on soil properties, growth, productivity, nutrient uptake, water productivity (WP), and irrigation. Two field experiments (2016/2017 and 2017/2018) were conducted in saline soil (ECe, 7.2 dS m−1) on faba been plants grown under three irrigation regimes (i.e., 100, 80, and 60% of crop evapotranspiration (ETc)) combined with three levels of ACBio (0, 5, and 10 t ha−1). Plants exposed to water stress presented a significant decrease in plant height, dry matter, leave area, chlorophyll content (SPAD), the quantum efficiency of photosystem II (Fv/Fm, Fv/F0, and PI), water status (membrane stability index and relative water content), and seed yield. Acidified biochar soil incorporation improved soil properties (chemical and physical), plant growth, physiological responses, WP, I-WUE, and contents of N, P, K, and Ca. Results revealed that the application of ACBio at 10 t ha−1 and 5 t ha−1 significantly increased seed yield by 38.7 and 25.8%, respectively, compared to the control. Therefore, ACBio incorporation may find application in the future as a potential soil amendment for improving growth and productivity of faba bean plants under deficit irrigation.

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Rapid Equilibration of Leaf and Stem Water Potential under Field Conditions in Almonds, Walnuts, and Prunes

HortTechnology ◽

10.21273/horttech.11.4.609 ◽

2001 ◽

Vol 11 (4) ◽

pp. 609-615 ◽

Cited By ~ 36

Author(s):

Allan Fulton ◽

Richard Buchner ◽

Cyndi Gilles ◽

Bill Olson ◽

Nick Bertagna ◽

...

Keyword(s):

Sample Size ◽

Water Potential ◽

Water Status ◽

Irrigation Management ◽

Irrigation Scheduling ◽

Field Conditions ◽

Equilibration Time ◽

Diurnal Changes ◽

Stem Water Potential ◽

Stem Water

Covering a plant leaf with a reflective, water impervious bag ensures that equilibrium is reached between the nontranspiring leaf and the stem, and appears to improve the accuracy of determining plant water status under field conditions. However, the inconvenience of covering the leaf for 1 to 2 hours before measuring stem water potential (SWP) has constrained on-farm adoption of this irrigation management technique. A second constraint has been that the requirement of midafternoon determinations limits the area that can be monitored by one person with a pressure chamber. This paper reports findings from field studies in almonds (Prunus dulcis),prunes (P. domestica), and walnuts (Juglans regia) demonstrating modified procedures to measure midday SWP, making it a more convenient and practical tool for irrigation management. For routine monitoring and irrigation scheduling, an equilibration period of 10 min or longer appears to be suitable to provide accurate SWP measurements. Based on the large sample sizes in this study, we estimate that measurement error related to equilibration time for SWP can be reduced to an acceptable level [0.05 MPa (0.5 bar)] with a sample size of about 10 leaves when using a 10-min equilibration period. Under orchard conditions where tree growth and health appears uniform, a sample of one leaf per tree and 10 trees per irrigation management unit should give an accurate mean indicator of orchard water status. Under more variable orchard conditions a larger sample size may be needed. Midmorning and midday SWP both exhibited similar seasonal patterns and responded alike to irrigation events. On some occasions, midday SWP was accurately predicted from midmorning SWP and the change in air vapor pressure deficit (VPD) from midmorning to midday, but both over- and underestimate errors [to 0.3 MPa (3.0 bar)] appeared to be associated with unusually low or high diurnal changes in VPD, respectively. Hence, direct measurement of SWP under midday conditions (about 1300 to 1500 hr) is still recommended.

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The Fractionation of 2H and 18O in Leaf Water of Barley

Functional Plant Biology ◽

10.1071/pp9910411 ◽

1991 ◽

Vol 18 (4) ◽

pp. 411 ◽

Cited By ~ 18

Author(s):

CD Walker ◽

RCM Lance

Keyword(s):

Flag Leaf ◽

Leaf Water ◽

Plant Parts ◽

Barley Cultivars ◽

Isotopic Compositions ◽

Water Composition ◽

Use Efficiency ◽

Stem Water ◽

Glasshouse Experiment ◽

Almost All

Small changes in the natural abundance of hydrogen and oxygen isotopes in water occur as a result of transpiration. We considered whether these may be sufficient to study the differences in water relations of barley cultivars having different water-use efficiency (W). A range of cultivars of varying W were grown in the glasshouse and in the field in breeders' plots. Foliage water samples were taken from a specific leaf stage over the course of a day. Certain field-grown cultivars had consistently higher 2H and 18O compositions in foliage water than others at almost all sampling times, resulting in a consistent ranking of the cultivars. Some evidence of a consistent ranking of isotopic compositions was also present in the glasshouse experiment. Concurrent variations in 2H and 18O compositions of the stem and leaf water reflect the conditions under which transpiration is occurring. The composition of stem water remains steady over the course of such experiments. The slope of the line connecting the isotopic compositions of the stem water and leaf water varied with changes in leaf water composition. This variation in slope was more pronounced under the more humid conditions of the glasshouse experiment, as is predicted from theory. The 2H and 18O compositions of water in the other plant parts, atmosphere and soil were also examined and porometry measurements were made. These indicated that daily variations in the contributions of soil and leaf water to the atmosphere occurred. This involves a maximum in the proportion of soil evaporation in the middle of the day, and a converse maximum in flag leaf evaporation early and late in the solar day.

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Carbon input management in temperate rice paddies: implications for methane emissions and crop response

Italian Journal of Agronomy ◽

10.4081/ija.2020.1607 ◽

2020 ◽

Author(s):

Chiara Bertora ◽

Barbara Moretti ◽

Matteo Peyron ◽

Simone Pelissetti ◽

Cristina Lerda ◽

...

Keyword(s):

Flag Leaf ◽

Crop Productivity ◽

Leaf Length ◽

Organic Fertilizers ◽

Mineral N ◽

Organic Input ◽

Organic C ◽

Ch4 Emissions ◽

Straw Incorporation ◽

The Impact

Agriculture contributes to over 20% of global anthropogenic GHG emissions and irrigated paddy fields account for 5–10% of CH4 emissions. Main organic input providing methanogenesis substrate is straw. We hypothesized that removing rice straw can mitigate CH4 emissions, and that replacing its carbon (C) input with raw or solid digestate can be a valuable alternative both for crop, soil and emission responses. A mesocosm study was setup to follow crop growth, changes in soil pore water chemistry (dissolved Fe(II) and dissolved Organic C), and CH4 emissions over one cropping season on soil treated with the combination of two straw managements (removal or incorporation) and three fertilizations (mineral, raw digestate, solid digestate). Soils not receiving straw on average emitted 38 % less than soils after straw incorporation, while the two organic fertilizers did not increase emissions with respect to mineral N application. Furthermore, straw incorporation induced a yield depression independently from the fertilization strategy, probably as a result of N immobilization, especially in early stages. This was evidenced by early SPAD observations and flag leaf length, and both grain and straw final production. Moreover, the two organic fertilizers were not fully able to sustain crop N requirements with respect to the mineral fertilizer. Straw management was therefore decisive for determining both rice yield and CH4 emissions, while the impact of fertilization treatments was crucial only for crop productivity.

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Time-Series of Vegetation Indices (VNIR/SWIR) Derived from Sentinel-2 (A/B) to Assess Turgor Pressure in Kiwifruit

10.20944/preprints202009.0625.v1 ◽

2020 ◽

Author(s):

Alberto Jopia ◽

Francisco Zambrano ◽

Waldo Pérez-Martínez ◽

Paulina Vidal-Páez ◽

Julio Molina ◽

...

Keyword(s):

Crop Production ◽

Management Practices ◽

Water Status ◽

Vegetation Indices ◽

Turgor Pressure ◽

Security Risk ◽

Vegetative Development ◽

Water Sensor ◽

Use Efficiency ◽

Sentinel 2

For more than ten years, Central Chile faces drought conditions, which impact crop production and quality, increasing food security risk. Under this scenario, implementing management practices that allow increasing water use efficiency is urgent. The study was carried out in kiwifruit trees, located in the O’Higgins region, Chile; for season 2018-2019 and 2019-2020. We evaluate nine vegetation indices in the VNIR and SWIR regions derived from Sentinel-2 (A/B) satellites to know how much variability in the canopy water status could explain. Over the study's site were installed sensors that continuously measure the leaf's turgor pressure (Yara Water-Sensor). A strong correlation between turgor pressure and vegetation indices was obtained with the Spearman's rho coefficient ($\rho$). However, the NIR range's indices were influenced by the vegetative development of the crop rather than its water status. Red-edge showed better performance as the vegetative growth did not affect it. It is necessary to expand the study to consider higher variability in kiwifruit's water conditions and incorporate the sensitivity of different wavelengths.

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13C Labeling kinetics of sucrose in glumes indicates significant refixation of respiratory CO2 in the wheat ear

Functional Plant Biology ◽

10.1071/pp01072 ◽

2001 ◽

Vol 28 (10) ◽

pp. 1047 ◽

Cited By ~ 8

Author(s):

Thomas Gebbing ◽

Hans Schnyder

Keyword(s):

Isotope Composition ◽

Flag Leaf ◽

Triticum Aestivum L ◽

Sole Source ◽

Water Soluble ◽

Atmospheric Co2 ◽

Soluble Carbohydrates ◽

Diurnal Changes ◽

Flag Leaves ◽

Kinetics Of

Photosynthesis by the vegetative structures of the ear (i.e. glumes) of wheat (Triticum aestivum L.) may draw on two sources of CO2: atmospheric CO2 and CO2 originating from respiration within the ear. We exposed wheat plants to a changed C isotope composition (δ) of one of the two sources, atmospheric CO2, to assess the contributions of atmospheric and respiratory CO2 to ear photosynthesis by following the labeling kinetics of water-soluble carbohydrates (WSC; fructose, glucose, sucrose, fructan) in glumes. Experiments included sampling during diurnal cycles and after extended exposures (7 and 14 d). The labeling kinetics of sucrose in the flag leaf and grains was also determined. Significant diurnal changes in sucrose content (depletion during dark and accumulation during light periods) were observed in flag leaves and in glumes. In flag leaves (but not in glumes) the sucrose accumulating during the light period had a d that was close to the value expected if atmospheric CO2 (with changed δ) was the sole source of CO2 for photosynthesis. The δ of sucrose in glumes did not saturate after extended exposure to the labeling CO2 indicating the utilization of unlabeled (respiratory) CO2 for photosynthesis (i.e. refixation). Short-term labeling indicated that 73% of the sucrose accumulating in glumes after the start of labeling came from fixation of respiratory CO2. Stable C isotope discrimination during glume photosynthesis is discussed.

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