Correlations of Leaf Relative Water Content, Canopy Temperature, and Spectral Reflectance in Perennial Ryegrass Under Water Deficit Conditions

Accurate, rapid, and nondestructive estimates of turfgrass leaf water status are important for site-specific irrigation and drought stress management. The objective of this study was to identify changes and correlations among the canopy reflectance, canopy temperature, and leaf relative water content (RWC) of perennial ryegrass (Lolium perenne L.) under water deficit conditions. Six cultivars of perennial ryegrass were subjected to dry-downs in the field from May to Aug. 2007 and from June to Aug. 2008. Turf quality was positively correlated with soil moisture (SM), RWC, and normalized difference vegetation index (NDVI), but negatively correlated with canopy and ambient temperature differentials (ΔT). ΔT was well correlated with RWC (r = –0.77 to –0.78) and SM (r = –0.66 to –0.74), whereas SM was correlated with RWC (r = 0.64 to 0.74) across seasons in both years. When a wide range of stress symptoms occurred in July and Aug., RWCs became highly correlated with ΔT (r = –0.80 to –0.89) and NDVI (r = 0.77 to 0.81), whereas ΔT was correlated with NDVI (r = –0.70 to –0.80) in both years. SM was well correlated with RWC (r = 0.71 to 0.80), NDVI (r = 0.70 to 0.73), and ΔT (r = –0.76 to –0.78) in July and August in both years. These results suggest that changes in ΔT can be used to predict well the leaf water and soil moisture content of perennial ryegrass under water deficit conditions. Combined with NDVI, the correlations can be used for direct mapping of the variability in grass water status, thus improving irrigation management.

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PENGARUH CEKAMAN KURANG AIR TERHADAP BEBERAPA KARAKTER FISIOLOGIS TANAMAN NILAM (Pogostemon cablin Benth)

Jurnal Penelitian Tanaman Industri ◽

10.21082/jlittri.v19n3.2013.108-116 ◽

2020 ◽

Vol 19 (3) ◽

pp. 108

Author(s):

SETIAWAN SETIAWAN ◽

TOHARI TOHARI ◽

DJA’FAR SHIDDIEQ

Keyword(s):

Soil Moisture ◽

Moisture Content ◽

Water Content ◽

Water Deficit ◽

Relative Water Content ◽

Soil Moisture Content ◽

Block Design ◽

Leaf Water ◽

Pogostemon Cablin ◽

Relative Water

ABSTRAK Nilam (Pogostemon cablin Benth) merupakan salah satu tanaman penghasil minyak atsiri yang dikenal dengan minyak nilam (patchouli oil). Salah satu kendala dalam pengembangan tanaman nilam adalah peka terhadap kekurangan air. Perubahan iklim cenderung menyebabkan lebih sering terjadi kekeringan di sejumlah wilayah termasuk Indonesia sehingga dalam pengembangan tanaman nilam diperlukan varietas toleran terhadap cekaman kurang air. Terdapat tiga varietas unggul nilam (Tapaktuan, Sidikalang, dan Lhokseumawe) dengan produksi minyak (290-375 kg/ha) dengan kadar patchouli alkohol 32–33%. Penelitian bertujuan untuk mengevaluasi respon fisiologis 4 varietas/aksesi tanaman nilam terhadap cekaman kurang air. Penelitian dilaksanakan di rumah kaca di Bogor pada tahun 2012. Penelitian menggunakan RAK faktorial dengan tiga ulangan. Faktor pertama 4 varietas/aksesi nilam (V) yaitu Sidikalang, Lhokseumawe, Tapaktuan, dan Bio-4. Faktor kedua empat interval penyiraman (W) yaitu 1, 3, 6, dan 9 hari sekali. Evaluasi pengaruh cekaman kurang air dilakukan terhadap beberapa karakter fisiologi tanaman nilam. Pengamatan dilakukan antara lain terhadap peubah kadar lengas tanah, konduktivitas stomata (Gs), laju transpirasi (Tr), kandungan air nisbi (KAN), potensial air daun (PAD) dan kandungan prolin daun. Hasil penelitian menunjukkan bahwa terjadi penurunan kadar lengas tanah, konduktivitas stomata, laju transpirasi, dan KAN pada semua varietas, sedangkan PAD dan kadar prolin meningkat seiring dengan semakin lamanya interval penyiraman. Kadar prolin tertinggi pada interval 9 hari sekali pada varietas Sidikalang. Tidak terdapat perbedaan respon varietas/aksesi nilam yang diuji. Kata kunci: Pogostemon cablin Benth, cekaman kurang air, karakter fisiologis.ABSTRACT Patchouli (Pogostemon cablin Benth) is one of plant that produces patchouli oil call patchouli oil. However, patchouli is susceptible to drought. The effect of global warming which changes rainfall pattern caused droughts in several regions including Indonesia. Therefore, it is important to find patchouli variety which is relatively tolerant to drought. Tapaktuan, Sidikalang, dan Lhokseumawe are three varieties of patchouli which produce high essential oil (290-375 kg/ha) with high patchouli alcohol content (32–33%). The objective of this research was to evaluate the physiological responses of four varieties/clone of patchouli to drought. The experiment was conducted at greenhouse at Cimanggu, Bogor from February to July 2012. The research was designed in randomized factorial block design (RBD) with three replications. The first factor was four varieties/clone of patchouli (V) Sidikalang, Lhokseumawe, Tapaktuan, and Bio-4. The second factor was four watering intervals (W) every 1, 3, 6 and 9 days of watering. Parameters evaluated were physiological characteristics, soil moisture content, stomatal conductance, transpiration rate (Tr), leaf water potential, relative water content, and proline content of leaf. The results showed that soil moisture content, stomatal conductivity, transpiration rate and relative water content decreased, while leaf water potential and proline levels increased along with the increase of watering intervals. The highest proline level was at interval of nine days watering treatment on Sidikalang varieties. However, all varieties/clone have not different responses to water deficit. Key words: Pogostemon cablin Benth,water deficit, physiological characteristics

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Reliability of leaf relative water content (RWC) measurements after storage: consequences for in situ measurements

Botany ◽

10.1139/cjb-2015-0065 ◽

2015 ◽

Vol 93 (9) ◽

pp. 535-541 ◽

Cited By ~ 17

Author(s):

Fallon M. Tanentzap ◽

Alexandra Stempel ◽

Peter Ryser

Keyword(s):

Water Content ◽

Relative Water Content ◽

Storage Temperature ◽

Water Status ◽

Plastic Bags ◽

Duration Of Storage ◽

Relative Water ◽

Leaf Relative Water Content ◽

Species Specific

Relative water content (RWC) is widely used to describe plant water status, and is commonly measured gravimetrically. The ephemeral nature of leaf fresh mass poses severe constraints for such measurements in field-grown plants. These constraints can be overcome by transporting the leaves in waterproof containers into the lab. However, even then, leaves lose water, and other changes may happen. The effects of a delay on the measurement of RWC have not been quantified so far. In this study, the influence of duration of storage up to 96 h and storage temperature on RWC and its components was investigated for four species. Alnus incana subsp. rugosa (Du Roi) R.T. Clausen, Impatiens capensis Meerb., and Scirpus microcarpus J.Presl & C.Presl leaves were stored in plastic bags, whereas those of Comptonia peregrina (L.) J.M.Coult. were stored in plastic vials. RWC remained within 5% of the initial value during 24 h cool storage, but after that, larger changes were observed. The effects of storage were species specific, being most pronounced in species poorly protected against desiccation, and under warm conditions. The effects of storage were not only limited to water loss, but also included cellular degradation. In general, storage at 10 °C for 24 h enables measurement of RWC for field-grown plants with accuracy of a few percent, but care has to be taken with species vulnerable to desiccation, possibly requiring faster measurement and a cooler storage temperature.

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Assessment of flag leaf water status as drought tolerance discriminating trait in durum wheat (Triticum turgidum var durum L.)

10.30574/msarr.2021.2.1.0026 ◽

2021 ◽

Vol 2 (1) ◽

pp. 016-027

Author(s):

Hadda Mebarki ◽

Ouassila Ziane ◽

Hadjer Merbah ◽

Hamenna Bouzerzour

Keyword(s):

Water Content ◽

Water Loss ◽

Relative Water Content ◽

Water Saturation ◽

Water Status ◽

Leaf Water ◽

Leaf Water Status ◽

Water Saturation Deficit ◽

Saturation Deficit ◽

Relative Water

Drought is a prominent limiting factor that impacts negatively durum wheat grain yield. Ten durum wheat breeding lines were evaluated under rainfall conditions at the Field Crop Institute Agricultural Experimental Station of Setif, Algeria, during the 2016/2017 cropping season. The investigation aimed to study the ability of flag leaf water status to discriminate among varieties for drought tolerance trait. Significant variability was observed among the tested varieties for leaf dry, wilted and turgid weights, leaf relative water content, water saturation deficit and excised water loss, after three wilting periods of 30, 60 and 90 minutes dehydration at 40°C. The assessed breeding lines were differentially categorized as drought tolerant and drought sensitive based on either relative water content or water saturation deficit or excised leaf water loss genotypic mean values. Correlation, principal components and cluster analyses indicated an unwanted significant association between excised leaf water loss and relative water content and water saturation deficit and classified the assessed entries into three clusters (CI, C2 and C3). Cluster C1 had high relative water content, low water saturation deficit but high excised water loss, while C3 had low relative water content, low excised leaf water but high-water saturation deficit, C2 being intermediate. Crosses between distant clusters (C1 vs C3) are proposed to generate more variability of the targeted traits in progeny population and to break undesirable linkage between alleles controlling leaf water status, allowing to select efficiently drought tolerant genotypes.

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Towards Estimation of Seasonal Water Dynamics of Winter Wheat from Ground-Based L-Band Radiometry

10.5194/bg-2021-71 ◽

2021 ◽

Author(s):

Thomas Jagdhuber ◽

François Jonard ◽

Anke Fluhrer ◽

David Chaparro ◽

Martin J. Baur ◽

...

Keyword(s):

Soil Moisture ◽

Water Content ◽

Relative Water Content ◽

Water Status ◽

Water Dynamics ◽

Relative Water ◽

L Band ◽

The Difference ◽

Vegetation Water ◽

Flow Resistances

Abstract. The vegetation optical depth (VOD) parameter contains information on plant water content and biomass, and can be estimated alongside soil moisture from currently operating satellite radiometer missions, such as SMOS (ESA) and SMAP (NASA). The estimation of water fluxes, such as plant water uptake (PWU) and transpiration rate (TR), from these Earth system parameters (VOD, soil moisture) requires assessing potential (suction tension) gradients of water and flow resistances in the soil, the vegetation and the atmosphere, yet it remains an elusive challenge especially on global scale. Here, we used a field-scale experiment to test mechanistic models for the estimation of seasonal water fluxes (PWU and TR) of a winter wheat stand including measurements of soil moisture, VOD, and relative air humidity (RH) under a controlled environment. We utilized microwave L-band observations from a tower-based radiometer to estimate VOD of a wheat stand during the 2017 growing season at the Selhausen laboratory in Germany. From VOD, we first extracted the gravimetric moisture of vegetation and then determined subsequently the relative water content (RWC) and the vegetation water potential (VWP) of the wheat field. Although the relative water content could directly be estimated from VOD, our results indicate this may be problematic for the phenological phases, when rapid biomass and plant structure development take place in the wheat canopy. The water uptake from the soil to the wheat plants was estimated from the difference between the soil and vegetation potentials divided by flow resistance from soil into wheat plants. The transpiration rate from the wheat plants into the atmosphere was obtained from the difference between the vegetation and atmosphere potentials divided by flow resistances from plants to the atmosphere. For this, the required soil matric potential (SMP), the vapor pressure deficit and the flow resistances were obtained from on-site observations of soil, plant and atmosphere and simple mechanistic models. This pathfinder study shows that the L-band microwave radiation contains valuable information on vegetation water status that enables the estimation of water dynamics (up to fluxes) from the soil via wheat plants into the atmosphere, when combined with additional information of soil and atmosphere water content. Still, assumptions when estimating the vegetation water potential from relative water content as well as when estimating the water flow resistances between soil, wheat plants and atmosphere had to be made. Moreover, validation of water flux estimates for assessing their absolute accuracy could not be performed due to a lack of in situ PWU and TR measurements. Nonetheless, our estimates of water status, potentials and fluxes show the expected temporal dynamics and intercompare reasonably well in absolute terms, providing confidence in further developing the proposed approach. Our findings support that passive microwave remote sensing techniques allow for the estimation of vegetation water dynamics next to traditionally measured stand-scale or plot-scale techniques. This might shed light on the potential capabilities of monitoring water dynamics in the soil-plant-atmosphere system using wide-area, remote sensing-based Earth observation data.

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Physiological Mechanism and Genotypic Variation in Drought Tolerance of Processing Carrots

HortScience ◽

10.21273/hortsci.39.4.855c ◽

2004 ◽

Vol 39 (4) ◽

pp. 855C-855 ◽

Cited By ~ 1

Author(s):

Rajasekaran Lada* ◽

Azure Stiles ◽

Christine Pettipas

Keyword(s):

Soil Moisture ◽

Drought Tolerance ◽

Water Content ◽

Water Deficit ◽

Relative Water Content ◽

Stem Elongation ◽

Physiological Mechanism ◽

Membrane Function ◽

Xylem Pressure Potential ◽

Relative Water

Processing carrots are mainly grown under rain-fed conditions in Nova Scotia, and thus become vulnerable to frequent periods of drought. Prolonged drought results in significant reductions in the yield and quality of carrot crops. Resistance to water deficit is gene controlled and it is essential to identify the genotypes that withstand water stress. It is equally important to understand the physiological mechanism(s) that contribute to drought tolerance. Physiological measurements were made on eight carrot varieties exposed to natural drought in a controlled greenhouse. Measurements were made on net photosynthesis, soil moisture, relative water content, membrane injury index, xylem pressure potential, and stem elongation. Overall, the slicer variety Bergen sustained normal plant functions under drought stress better than any of the other varieties. Bergen maintained stem elongation, photosynthetic activity, membrane function, and relative water content under droughted conditions. Another study was conducted to identify carrot varieties that are naturally resistant to drought. A mass screening of 85 slicer, dicer, and cut and peel varieties was conducted under greenhouse conditions. Two-week-old seedlings were exposed to gradual water deficit and observed for visual symptoms of wilting each day as soil moisture declined. Each variety was assigned a wilting score based upon the number of days it withstood drought (min = 1, max = 5). The dicer variety, Prodigy, was the only variety to score a 5 indicating the most drought resistance. Other varieties that withstood drought well were `Caropak', `Interceptor', `Oranza', and `Berlanda'. Varieties such as KC713126, Cello712113, and Cello711411 were more sensitive to water deficit and began to wilt 8 days after drought was imposed.

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Capillary Mats Modify Media Moisture Content during Mist Propagation of Chrysanthemum Cuttings

HortScience ◽

10.21273/hortsci.31.4.634a ◽

1996 ◽

Vol 31 (4) ◽

pp. 634a-634

Author(s):

Jennifer Marohnic ◽

Robert Geneve ◽

Jack W. Buxton

Keyword(s):

Water Potential ◽

Water Content ◽

Leaf Water Potential ◽

Relative Water Content ◽

Dry Weight ◽

Leaf Water ◽

Root Numbers ◽

Relative Water ◽

Leaf Relative Water Content ◽

Initial Root

Capillary mats were used to vary the water content in oasis blocks during mist propagation of chrysanthemum cuttings. Mats placed on the surface of the propagation bench extended over the edge of the bench and downward a distance of either 0 or 20 cm. Oasis blocks with chrysanthemum cuttings `Boaloi' and `Salmon Charm' were placed on mats under intermittent mist (10 seconds every 5 minutes) between 5 am and 8 pm. Relative water content, mL of water/gram oasis, and leaf water potential were measured at noon every 5 days. After 26 days number of roots per cutting was evaluated. Water content in the oasis block was reduced by 49% (450 to 219 mL/g dry weight of oasis) by hanging the capillary mat 20 cm over the edge of the bench compared to 0 cm treatment. Cuttings showed an increase in leaf relative water content from 49% and 51% at day 1 to 65% and 71% by day 11 for `Boaloi' and `Salmon Charm', respectively. Following initial root formation, leaf relative water content increased to 85%. Over the course of the experiment `Boaloi' and `Salmon Charm' showed an average reduction in leaf water potential of 0.14 and 0.08 MPA, respectively. `Boaloi' showed overall higher root numbers than `Salmon Charm'; however, no difference in rooting between mat treatments was observed.

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Short communication: Physiological response to drought in North Sulawesi (Indonesia) local rice (Oryza sativa) cultivars at the tissue level in hydroponic culture

Biodiversitas Journal of Biological Diversity ◽

10.13057/biodiv/d220108 ◽

2020 ◽

Vol 22 (1) ◽

Author(s):

Song Ai Nio ◽

RISA JUNITA MEREH ◽

DANIEL PETER MANTILEN LUDONG

Keyword(s):

Water Content ◽

Water Deficit ◽

Relative Water Content ◽

Physiological Response ◽

Tissue Level ◽

Hydroponic Culture ◽

North Sulawesi ◽

Relative Water ◽

Leaf Relative Water Content ◽

Peg 8000

Abstract. Nio SA, Mereh RJ, Ludong DPM. 2021. Short communication: Physiological response to drought in North Sulawesi (Indonesia) local rice (Oryza sativa) cultivars at the tissue level in hydroponic culture. Biodiversitas 22: 58-64. Water availability influenced the metabolism processes in the plants and this condition could change water balance in the cells as well as restricting the growth and production of crops. This study aimed to evaluate the effect of in vitro polyethylene glycol (PEG) 8000-induced water deficit on the relative water content and chlorophylls (total, a, and b) concentration as physiological response in leaf segments of North Sulawesi (Indonesia) local rice cultivars (cvs. Superwin, Ombong, Burungan, and Temo). The rice leaves were cut into 1 cm x 1 cm segments and were treated under both control (0 MPa) and water deficit (-0.25 and -0.5 MPa) using PEG 8000 as osmoticum. The experiment was factorial completely randomized block design with 4 sampling times (0, 4, 8, and 12 hours) and three replicates. Interaction of water deficit duration and PEG 8000 treatment resulted in a significant difference in leaf relative water content. The leaf relative water content at PEG -0.5 MPa after 8 and 12 hours of treatments was lower than at control (PEG 0 MPa) when the treatment commenced (0 hour). The concentration of chlorophylls (total, a, and b) were significant differences among cultivars and water deficit durations. This study showed that leaf relative water content was a potential physiological indicator of PEG 8000-induced water deficit in North Sulawesi local rice at the tissue level in hydroponic culture.

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Relationship between leaf relative water content during reproductive stage water deficit and grain formation in rice

Field Crops Research ◽

10.1016/s0378-4290(02)00037-0 ◽

2002 ◽

Vol 76 (2-3) ◽

pp. 165-174 ◽

Cited By ~ 44

Author(s):

R. Lafitte

Keyword(s):

Water Content ◽

Water Deficit ◽

Relative Water Content ◽

Reproductive Stage ◽

Grain Formation ◽

Relative Water ◽

Leaf Relative Water Content

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The Method of Plant Water Status Measurement in Sweet Potato (Ipomoea Batatas (L) Lam.)

Beccariana Botanical Research Bulletin ◽

10.30862/bbrp.v7i1.274 ◽

2010 ◽

Vol 7 (1) ◽

Author(s):

Saraswati Prabawardani

Keyword(s):

Water Content ◽

Sweet Potato ◽

Relative Water Content ◽

Water Status ◽

Plant Water Status ◽

Equilibration Time ◽

Plant Water ◽

Font Size ◽

Potato Leaf ◽

Relative Water

The measurement of plant water status such as leaf water potential (LWP) and leaf relative water content (RWC) is important part of understanding plant physiology and biomass production. Preliminary study was made to determine the optimum amount of leaf abrasion and equilibration time of sweet potato leaf inside the thermocouple psychrometer chambers. Based on the trial, the standard equilibration time curve of a Peltier thermocouple for sweet potato leaf was between 2 and 3 hours. To increase the water vapour conductance across the leaf epidermis the waxy leaf cuticle should be removed or broken by abrasion. The result showed that 4 times leaf rubbings was accepted as the most effective way to increase leaf vapour conductance of sweet potato in the psychrometer chambers. In calculating the leaf relative water content, unstressed water of sweet potato leaves require 4 hours imbibition, whereas water stressed of sweet potato leaves require 5 to 6 hours to reach the saturation time. Either leaf water potential or relative water content can be used as a parameter for plant water status in sweet potato.

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