RELATIONSHIPS BETWEEN THE LEAF WATER STATUS OF BARLEY AND SOIL WATER

1970 ◽  
Vol 50 (4) ◽  
pp. 363-370 ◽  
Author(s):  
AGUSTIN A. MILLAR ◽  
MURRAY E. DUYSEN ◽  
ENOCH B. NORUM

Total water potential of barley (Hordeum vulgare L.) leaves from plants grown under greenhouse and growth chamber conditions was divided into pressure and osmotic potential components, and their relationship to leaf relative water content was determined. Pressure potential approached zero at a water potential of about −32 bars, and a relative water content of about 65%. A change in the elasticity of leaves occurred at about 2 bars pressure potential and about −12 bars water potential. First visible wilting was observed between 75 and 80% relative water content. Transpiration decreased as leaf relative water content decreased but transpiration was independent of soil water content until about 16% (0.6 bar soil suction). First visible wilting of barley leaves was observed at soil water content between 9 and 13% (1–5 bars soil suction). Water potential and leaf relative water content decreased as the soil matric potential decreased. There was a shift to lower relative water content and water potential values as plants became older when the soil matric potential decreased.

1984 ◽  
Vol 11 (1) ◽  
pp. 31-35 ◽  
Author(s):  
J. M. Bennett ◽  
K. J. Boote ◽  
L. C. Hammond

Abstract Limited data exist describing the physiological responses of peanut (Arachis hypogaea L.) plants to tissue water deficits. Detailed field experiments which accurately define the water status of both the plant and soil are required to better understand the effects of water stress on a peanut crop. The objectives of the present study were 1) to describe the changes in leaf water potential components during a drying cycle, and 2) to define the relationships among soil water content, leaf water potential, leaf turgor potential, relative water content, leaf-air temperature differential, and leaf diffusive resistance as water stress was imposed on a peanut crop. During a 28-day drying period where both rainfall and irrigation were withheld from peanut plants, midday measurements of the physiological parameters and volumetric soil water contents were taken concurrently. As soil drying progressed, water extraction from the upper soil depths was limited as soil moisture approached 0.04 m3m-3. Leaf water potentials and leaf turgor potentials of nonirrigated plants decreased to approximately −2.0 and 0 MPa, respectively, by the end of the experimental period. Leaf water potentials declined only gradually as the average volumetric soil water content in the upper 90 cm of soil decreased from 0.12 to 0.04 m3m-3. Further reductions in soil water content caused large reductions in leaf water potential. As volumetric soil moisture content decreased slightly below 0.04 m3m-3 in the upper 90 cm, leaf relative water content dropped to 86%, leaf water potential approached −1.6 MPa and leaf turgor potential decreased to 0 MPa. Concurrently, stomatal closure resulted and leaf temperature increased above air temperature. Osmotic potentials measured at 100% relative water content were similar for irrigated and nonirrigated plants, suggesting little or no osmotic regulation.


Author(s):  
Agustina Asri Rahmianna ◽  
Dan Joko Purnomo

Drought stress during generative stage affected pod yield, yield components, seed and pod qualities of groundnut (Arachis hypogaea L.). The reseach was carried out to assess the effect of drought stress at various soil water availabilities during generative stage on pod yield, pod and seed physical qualities. The experiment was conducted at Muneng Experimental Farm, Probolinggo District during July-October 2012. Five genotypes were arranged in a RCB design, with 3 replicates. The replications were nested into four treatments of soil water availability (0-100, 0-85, 0-70,0-55 days after sowing/DAS). The pods were harvested at 102 days after sowing. The result showed that the shorter the water availability, the lower the leaf relative water content, pod and seed water contents, number of mature pods, seed size, and intact seeds weight. Pod yield reduced when water was available upto 55 DAS only. Turangga variety had the highest pod yield (1.626 ton ha-1) with low pod and seed physical qualities. GH-51 yielded in 1.076 ton ha-1 with superior pod and seed physical qualities. Despite of its lowest pod yield (0.964 ton ha-1), J-11 produced the same pod and seed physical qualities as GH 51 did. ICGV 86590 was superior on its pod yield (1.338 ton ha-1) with low pod and seed physical qualities. Kancil variety did not perform any superiority.<br /><br />Keywords: intact seeds, leaf relative water content, pod moisture content, seed moisture content


1967 ◽  
Vol 20 (2) ◽  
pp. 349 ◽  
Author(s):  
J Warren Wilson

The relation between the relative water content (R) and the pressure potential can be expressed through the coefficient of enlargement (e). The assumption that e does not vary with R is for many leaves a useful first approximation even when R is so low that pressure potential is negative. e is estimated at between 7 and 84 bars for various leaf types.


Author(s):  
Edvaldo B. Santana Júnior ◽  
Eugênio F. Coelho ◽  
Karoline S. Gonçalves ◽  
Jailson L. Cruz

ABSTRACT The purpose of the study was to evaluate the effect of salinity levels of irrigation water on physiology and growth of banana cultivars during the vegetative stage. The experiment was carried out following a completely randomized design in split plots, with four levels of salinity in irrigation water (0.5, 2.0, 3.0 and 4.0 dS m-1) and four banana cultivars (Pacovan, Prata Anã, BRS Platina and Princesa) with three repetitions. Stomatal conductance, transpiration, relative water content, leaf water potential and proline concentration were evaluated at 150 days after transplanting (DAT), besides plant height, stem diameter and leaf area. All variables showed sensitivity to the increase of salinity level of irrigation water. The results of soil water extraction, relative water content in leaf (RWC), leaf water potential and proline content differed (p ≤ 0.05) among the cultivars. Prata Anã and BRS Platina cultivars were the ones with lowest sensitivity, while Pacovan and BRS Princesa cultivars showed larger variation of soil water extraction and RWC with the increase in irrigation water salinity (electrical conductivity), being considered the ones of highest sensitivity to salinity in this study. Banana crop growth as a consequence of physiological effects was inhibited by the increase in water salinity, mainly in “BRS Princesa” cultivar.


HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 634a-634
Author(s):  
Jennifer Marohnic ◽  
Robert Geneve ◽  
Jack W. Buxton

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.


1978 ◽  
Vol 5 (2) ◽  
pp. 179 ◽  
Author(s):  
NC Turner ◽  
JE Begg ◽  
HM Rawson ◽  
SD English ◽  
AB Hearn

Concurrent measurements of leaf water potential, leaf osmotic potential, leaf relative water content, quantum flux density, leaf conductance, 14CO2 photosynthesis, soluble and insoluble sugars, starch and potassium concentrations were made diurnally on six occasions between flowering and maturity on upper leaves of irrigated and rainfed crops of soybean (cvv. Ruse and Bragg) and a rainfed crop of sorghum (cv. TX 610). With adequate soil water, sorghum had lower values of leaf conductance than did soybeans at high light and yet had higher rates of photosynthesis. Stage of plant development had no effect on either leaf conductance or photosynthesis of the youngest fully expanded leaves of both sorghum and soybean, but starch accumulation in the leaf over the day was less at grain-filling than at flowering in the soybean. Starch and sugar levels in the leaf had no apparent effect on photosynthesis. The daily minimum leaf water potential decreased in Ruse soybean from - 1.5 to -2.7 MPa as soil water was depleted. Late in the drying cycle, the daily minimum leaf water potential was higher in Bragg than in Ruse. In both cultivars, stomatal closure and decrease in 14CO2 photosynthesis commenced at leaf water potentials below - 1.5 MPa. Thus, the effect of water deficits on leaf conductance and photosynthesis occurred later in the drying cycle in Bragg than Ruse. As photosynthesis decreased with the depletion of soil water, starch accumulation in leaves of both cultivars of soybean decreased; changes in soluble and insoluble sugars and in potassium were small. The relationships among leaf water potential, osmotic potential, turgor potential, and leaf relative water content did not change with season or soil water depletion. Bragg and Ruse soybeans showed a similar response and both approached zero turgor at the same relative water content (82-83 %) and the same leaf water potential (- 1.5 to - 1.7 MPa). No evidence ofr osmotic adjustment was found in either soybean cultivar.


2015 ◽  
Vol 10 (4) ◽  
pp. 208 ◽  
Author(s):  
Lorenzo Barbanti ◽  
Ahmad Sher ◽  
Giuseppe Di Girolamo ◽  
Elio Cirillo ◽  
Muhammad Ansar

A better understanding of plant mechanisms in response to drought is a strong premise to achieving high yields while saving unnecessary water. This is especially true in the case of biomass crops for non-food uses (energy, fibre and forage), grown with limited water supply. In this frame, we investigated growth and physiological response of two genotypes of biomass sorghum (<em>Sorghum bicolor</em> (L.) Moench) to contrasting levels of soil moisture in a pot experiment carried out in a greenhouse. Two water regimes (high and low water, corresponding to 70% and 30% field capacity) were applied to JS-2002 and Trudan-8 sorghum genotypes, respectively bred for dry sub-tropical and mild temperate conditions. Two harvests were carried out at 73 and 105 days after seeding. Physiological traits (transpiration, photosynthesis and stomatal conductance) were assessed in four dates during growth. Leaf water potential, its components and relative water content were determined at the two harvests. Low watering curbed plant height and aboveground biomass to a similar extent (ca. 􀀀70%) in both genotypes. JS-2002 exhibited a higher proportion of belowground to aboveground biomass, <em>i.e</em>., a morphology better suited to withstand drought. Despite this, JS-2002 was more affected by low water in terms of physiology: during the growing season, the average ratio in transpiration, photosynthesis and stomatal conductance between droughty and well watered plants was, respectively, 0.82, 0.80 and 0.79 in JS-2002; 1.05, 1.08 and 1.03 in Trudan-8. Hence Trudan-8 evidenced a ca. 20% advantage in the three traits. In addition, Trudan-8 could better exploit abundant moisture (70% field capacity), increasing aboveground biomass and water use efficiency. In both genotypes, drought led to very low levels of leaf water potential and relative water content, still supporting photosynthesis. Hence, both morphological and physiological characteristics of sorghum were involved in plant adaptation to drought, in accordance with previous results. Conversely, the common assumption that genotypes best performing under wet conditions are less suited to face drought was contradicted by the results of the two genotypes in our experiment. This discloses a potential to be further exploited in programmes of biomass utilization for various end uses, although further evidence at greenhouse and field level is needed to corroborate this finding.


Author(s):  
Erum F H Kazi ◽  
Dr. Satish Kulkarni

Air pollution is one of major concerns in Pune City currently. Study highlights increase in Particulate matter from Vehicular sources & Urbanization in Karaj area is having harmful impact on the trees in the area. Leaf of Plant species such as Peepal( Ficusreligiosa),, Tamarind(Tamarindusindica), Rain tree( Samaneasaman), Ashoka( Saracaasoca), Manago( Mangiferaindica), Almond( Terminaliacatappa) , Banyan tree(Ficusbenghalensis) were selected and it was found that Ashoka( Saracaasoca), Mango tree( Mangiferaindica) showed Intermediate APTI whereas Peepal, Tamarind, Rain tree, Almond, Banyan tree were found to be Sensitive to pollution. KEYWORDS: Air Pollutants, APTI of plants, Total Chlorophyll, Ascorbic acid, p H of leaf, Relative water Content ( RWC)


Irriga ◽  
2018 ◽  
Vol 1 (01) ◽  
pp. 246
Author(s):  
Lígia Borges Marinho ◽  
José Antonio Frizzone ◽  
João Batista Tolentino Júnior ◽  
Janaina Paulino ◽  
Danilton Luiz Flumigan ◽  
...  

DINÂMICA DA ÁGUA NO SISTEMA SOLO-PLANTA NO CULTIVO DA PIMENTA TABASCO SOB DÉFICIT HÍDRICO1  LÍGIA BORGES MARINHO2; JOSÉ ANTONIO FRIZZONE3; JOÃO BATISTA TOLENTINO JÚNIOR4; JANAÍNA PAULINO5; DANILTON LUIZ FLUMIGNAN6 E DIEGO BORTOLOTI GÓES3    (1) Artigo extraído da tese do primeiro autor (2) Departamento Tecnologia e Ciências Sociais, Universidade do Estado da Bahia, av. Edgard Chastinet, São Geraldo, CEP 48905-680, Juazeiro, BA. Fone (74) 3611-7363. E-mail: [email protected](3) Departamento de Engenharia de Biossistemas/Escola Superior de Agricultura “Luiz de Queiroz” USP, Av. Pádua Dias, 11, CEP 13.418-900, Piracicaba/SP, E-mail(s): [email protected], [email protected]; (4) Campus Curitibanos, Universidade Federal de Santa Catarina, Curitibanos, SC. [email protected] (5) Universidade Federal de Mato Grosso UFMT, campus Sinop, Avenida Alexandre Ferronato Nº 1.200. Bairro: Setor Industrial. CEP: 78.550-000,  Sinop-MT, Email: [email protected] (6) Empresa Brasileira de Pesquisa Agropecuária, Agropecuária Oeste. Rodovia BR 163, km 253, Zona Rural, 79804970 - Dourados, MS,  Email: [email protected]  1 RESUMO  O objetivo da pesquisa foi acompanhar a variação da condição hídrica do solo e da planta de pimenta ‘Tabasco’ em função dos manejos de déficits hídricos impostos e determinar seu coeficiente de estresse hídrico. O experimento foi conduzido em ambiente protegido, no Departamento de Engenharia de Biossistemas da ESALQ - USP, Piracicaba-SP, de setembro de 2009 a julho de 2010. O delineamento experimental foi blocos casualizados, com quatro repetições, utilizando-se lâminas de irrigação a 100, 80, 60 e 40% da evapotranspiração da cultura diferenciadas a partir da fase vegetativa e da fase reprodutiva. O potencial da água na folha e no solo foi aferido com a câmara de pressão e tensiômetros, respectivamente. Houve variação do potencial mátrico, da extração de água no solo e do potencial de água na folha em função das lâminas e das épocas de diferenciação. Menores potenciais mátricos foram verificados quando o déficit de irrigação foi inicializado na fase vegetativa da pimenta. Os valores de coeficiente de estresse hídrico e o potencial de água na folha, ao alvorecer, indicaram que as pimenteiras estavam sob estresse moderado e severo, sendo a época reprodutiva da pimenta Tabasco a mais sensível à restrição hídrica.Palavras-chave: Capsicum frutencens L, tensiômetro, potencial da água no solo.                                                        MARINHO, L. B.; FRIZZONE, J. A.; TOLENTINO JÚNIOR, J. B.; PAULINO, J.; FLUMIGNAN, D. L.; GÓES, D. B.WATER DYNAMICS IN SOIL-PLANT SYSTEM IN THE CULTIVATION OF PEPPER TABASCO UNDER WATER DEFICIT  2 ABSTRACT The objective of the research was to determine the change in soil water condition and in Tabasco pepper plant according to the managements of water deficits. The experiment was conducted in a greenhouse at the Department of Biosystems Engineering of ESALQ - USP, Piracicaba-SP, from September 2009 to July 2010. The experimental design was randomized blocks with four replications, using irrigation depths to 100, 80, 60 and 40% of crop evapotranspiration in the vegetative phase and reproductive phase. The soil matric potential was measured by tensiometers installed at 0-20 and 20-40 cm depth. The most negative values of matric potential occurred in treatments submitted to the greater water deficit treatments that had higher water restriction imposed by the vegetative phase. For these, greater increase in water extraction in the deepest layer (40 cm) were also found.There were differences in matric potential of the soil, in ground water extraction and in leaf water potential in relation to the water depths and differentiation phases. The deficit irrigation that started in the vegetative phase led to greater reduction in soil matric potential due to the accumulated water deficit. The pepper plants have moderate to severe sensitivity to water deficit in the soil, with a higher sensitivity of the plants when water restriction is imposed during reproductive stages than when it is imposed during growing stages. Keywords : Capsicum frutencens, tensiometer; soil water potential


Sign in / Sign up

Export Citation Format

Share Document