Water Relations of Laticifers in Nerium oleander

1981 ◽  
Vol 8 (3) ◽  
pp. 329 ◽  
Author(s):  
WJS Downton
Keyword(s):  
Water Potential ◽  
Water Relations ◽  
Osmotic Potential ◽  
Water Status ◽  
Turgor Pressure ◽  
Death Valley ◽  
Nerium Oleander ◽  
Laboratory Measurements ◽  
Hydrocarbon Sources ◽  
Daily Changes

The water relations of laticifers in N. oleander were examined for plants growing in Death Valley, California, USA. Osmotic potential of laticifers in well watered plants paralleled the daily changes in leaf water potential. The turgor pressure of laticifers was usually less than bulk leaf turgor. Laticifer turgor was maintained in the absence of positive leaf turgor in severely water stressed plants (Ψw ͭ6 -7.0 MPa) and latex exuded when leaves were cut. The recovery in water status of leaves and laticifers following watering of the plants is described. Laboratory measurements confirmed that laticifer turgor differed from bulk leaf turgor and that it was maintained over a range of water potentials. These observations may have relevance for some of the latex-bearing plants currently being considered as future hydrocarbon sources.

The Response of Cotton (Gossypium hirsutum) Water Relations to Smooth Pigweed (Amaranthus hybridus) Competition

Weed Science ◽  
1984 ◽  
Vol 32 (1) ◽  
pp. 126-132 ◽  
Author(s):  
Bryan L. Stuart ◽  
Steven K. Harrison ◽  
John R. Abernathy ◽  
Daniel R. Krieg ◽  
Charles W. Wendt
Keyword(s):  
Gossypium Hirsutum ◽  
Water Potential ◽  
Soil Water ◽  
Water Relations ◽  
Water Status ◽  
Turgor Pressure ◽  
Growing Season ◽  
Photon Flux ◽  
Amaranthus Hybridus ◽  
Smooth Pigweed

Field tests in 1980 and 1981 indicated that smooth pigweed (Amaranthus hybridusL.) competition affected cotton (Gossypium hirsutumL. ‘GSA 71′) water relations by reducing plant water status early in the season and by shading late in the season. Early in the growing season, cotton leaf water potential and turgor pressure reductions as great as 0.53 and 0.21 MPa, respectively, were measured at a smooth pigweed density of 2.5 plants m-2. Late in the 1981 growing season, smooth pigweed reduced the photon flux density reaching the cotton canopy by 90% at midday. The shaded conditions resulted in increased cotton water potential under low soil water conditions, but the inability to reduce solute potential lowered the turgor pressure of cotton, irrespective of soil water level. Comparisons of smooth pigweed and cotton water relations indicated that smooth pigweed had the capacity to maintain higher water potential and turgor pressure than cotton. The more favorable water status of smooth pigweed resulted in part from increased water extraction at lower depths in the soil profile and higher diffusive resistance, thereby reducing transpirational water loss.

Carbon dioxide enrichment and water stress interaction on growth of two tomato cultivars

1984 ◽  
Vol 102 (3) ◽  
pp. 687-693 ◽  
Author(s):  
Alejandra Paez ◽  
H. Hellmers ◽  
B. R. Strain
Keyword(s):  
Carbon Dioxide ◽  
Water Stress ◽  
Plant Growth ◽  
Water Potential ◽  
Leaf Water Potential ◽  
Osmotic Potential ◽  
Water Status ◽  
Carbon Dioxide Concentration ◽  
Leaf Water ◽  
Total Leaf

SummaryIf atmospheric carbon dioxide concentration continues to increase, plant growth and crop yield could be affected. New Yorker and Better Boy cultivars of tomato (Lycopersicon esculentum) were used to investigate possible intraspecific variation in the response of crop species to increased CO2. Because precipitation and temperature are predicted to change with the increasing atmospheric CO2 concentration, the response of the two cultivars to the interaction between CO2 and water stress was also examined. Seeds of the two cultivars were germinated and grown under controlled environmental conditions, in either 350 or 675 μ1 CO2/1.The plant water status of the two cultivars was inherently different but was little affected by the CO2 concentration when the plants were well watered. When water was withheld for 5 days the total leaf water potential and osmotic potential decreased in both CO2 treatments but less rapidly in high CO2 than in low. Under low CO2 total leaf water potential decreased to a lower value than osmotic potential. The differences were due, at least in part, to the reduced stomatal conductance and transpiration rate under high CO2.Increased CO2 ameliorated the detrimental effects of drought stress on plant growth. The results indicate that increased CO2 could differentially affect the relative drought resistance of species cultivars.

Salinity and drought stress effects on foliar ion concentration, water relations, and photosynthetic characteristics of orchard citrus

1988 ◽  
Vol 39 (4) ◽  
pp. 619 ◽  
Author(s):  
JP Syvertsen ◽  
J Lloyd ◽  
PE Kriedemann
Keyword(s):  
Drought Stress ◽  
Gas Exchange ◽  
Water Potential ◽  
Water Relations ◽  
Osmotic Potential ◽  
High Salinity ◽  
Leaf Water ◽  
Ion Concentration ◽  
Drought Treatment ◽  
Mature Leaves

Effects of salinity and drought stress on foliar ion concentration, water relations and net gas exchange were evaluated in mature Valencia orange trees (Citrus sinensis [L.] Osbeck) on Poncirus trifoliata L. Raf. (Tri) or sweet orange (C. sinensis, Swt) rootstocks at Dareton on the Murray River in New South Wales. Trees had been irrigated with river water which averaged 4 mol m-3 chloride (Cl-) or with river water plus NaCl to produce 10, 14 or 20 mol m-3 Cl- during the previous 3 years. Chloride concentrations in leaves of trees on Tri were significantly higher than those on Swt rootstock. Foliar sodium (Na+) and Cl- concentrations increased and potassium (K+) concentrations decreased as leaves aged, especially under irrigation with 20 mol m-3 Cl-. Leaf osmotic potential was reduced as leaves matured and also by high salinity so that reductions in leaf water potential were offset. Mature leaves had a lower stomatal conductances and higher water use efficiency than young leaves. After 2 months of withholding irrigation water, leaves of low salinity trees on Tri rootstock had higher rates of net gas exchange than those on Swt rootstock, indicating rootstock-affected drought tolerance. Previous treatment with 20 mol m-3 Cl- lowered leaf area index of all trees by more than 50%, and resulted in greater reserves of soil moisture under partially defoliated trees after the drought treatment. This was reflected in more rapid evening recovery of leaf water potential and less severe reductions in net gas exchange after drought treatment in high salinity trees on Swt rootstock. High salinity plus drought stress increased Na+ content of leaves on Swt, but not on Tri rootstocks. Drought stress had no additive effect, with high salinity on osmotic potential of mature leaves. Thus, the salinity-induced reduction in leaf area appeared to be independent of the Cl- exclusion capability of the rootstock and decreased the effects of subsequent drought stress on leaf water relations and net gas exchange.

Effects of sulfur dioxide on water relations of hybrid poplar foliage and bark

1982 ◽  
Vol 12 (3) ◽  
pp. 612-616 ◽  
Author(s):  
Alan R. Biggs ◽  
Donald D. Davis
Keyword(s):  
Sulfur Dioxide ◽  
Water Potential ◽  
Water Relations ◽  
Osmotic Potential ◽  
Hybrid Poplar ◽  
Leaf Conductance ◽  
Unexposed Control ◽  
Poplar Cuttings ◽  
Induced Changes

Hybrid poplar cuttings were exposed to 0.25 ppm SO2 for 72 h/week for 14 consecutive weeks in 1979. In 1980, a second set of cuttings was exposed to 0.12 ppm SO2 for 72 h/week for 6 consecutive weeks. Foliar and bark water potential, osmotic potential, and the pressure component, as well as leaf conductance, were determined during or following exposure and compared with data from unexposed control plants. Leaf conductance was stimulated during 72-h exposures to 0.25 ppm SO2. Six 72 h/week exposures to 0.12 ppm SO2 had no effect on conductance, but induced changes in foliar water potential and osmotic potential.

Divergence in plant water-use strategies in semiarid woody species

2017 ◽  
Vol 44 (11) ◽  
pp. 1134 ◽  
Author(s):  
Rachael H. Nolan ◽  
Kendal A. Fairweather ◽  
Tonantzin Tarin ◽  
Nadia S. Santini ◽  
James Cleverly ◽  
...  
Keyword(s):  
Water Potential ◽  
Leaf Area ◽  
Leaf Water Potential ◽  
Specific Leaf Area ◽  
Osmotic Potential ◽  
Water Status ◽  
Stomatal Closure ◽  
Woody Species ◽  
Leaf Water ◽  
Leaf Water Status

Partitioning of water resources amongst plant species within a single climate envelope is possible if the species differ in key hydraulic traits. We examined 11 bivariate trait relationships across nine woody species found in the Ti-Tree basin of central Australia. We found that species with limited access to soil moisture, evidenced by low pre-dawn leaf water potential, displayed anisohydric behaviour (e.g. large seasonal fluctuations in minimum leaf water potential), had greater sapwood density and lower osmotic potential at full turgor. Osmotic potential at full turgor was positively correlated with the leaf water potential at turgor loss, which was, in turn, positively correlated with the water potential at incipient stomatal closure. We also observed divergent behaviour in two species of Mulga, a complex of closely related Acacia species which range from tall shrubs to low trees and dominate large areas of arid and semiarid Australia. These Mulga species had much lower minimum leaf water potentials and lower specific leaf area compared with the other seven species. Finally, one species, Hakea macrocarpa A.Cunn ex.R.Br., had traits that may allow it to tolerate seasonal dryness (through possession of small specific leaf area and cavitation resistant xylem) despite exhibiting cellular water relations that were similar to groundwater-dependent species. We conclude that traits related to water transport and leaf water status differ across species that experience differences in soil water availability and that this enables a diversity of species to exist in this low rainfall environment.

scholarly journals POTENCIAL HÍDRICO FOLIAR E DESENVOLVIMENTO VEGETATIVO DO CAFEEIRO CONILON SOB DIFERENTES LÂMINAS DE IRRIGAÇÃO NA REGIÃO E CAMPOS DOS GOYTACAZES - RJ

Irriga ◽  
2021 ◽  
Vol 26 (1) ◽  
pp. 13-28
Author(s):  
Diego Albani Furlan ◽  
Elias Fernandes De Sousa ◽  
José Carlos Mendonça ◽  
Claudio Luiz Melo De Souza ◽  
Romildo Domingos Gottardo ◽  
...  
Keyword(s):  
Water Potential ◽  
Leaf Water Potential ◽  
Water Status ◽  
Turgor Pressure ◽  
Leaf Water ◽  
Vegetative Development ◽  
Crown Diameter ◽  
Biometric Parameters ◽  
The Moment ◽  
Water Supplementation

POTENCIAL HÍDRICO FOLIAR E DESENVOLVIMENTO VEGETATIVO DO CAFEEIRO CONILON SOB DIFERENTES LÂMINAS DE IRRIGAÇÃO NA REGIÃO E CAMPOS DOS GOYTACAZES - RJ     DIEGO ALBANI FURLAN1; ELIAS FERNANDES DE SOUSA2; JOSÉ CARLOS MENDONÇA3; CLAUDIO LUIZ MELO DE SOUZA4; ROMILDO DOMINGOS GOTTARDO 5 E RODOLLPHO ARTUR DE SOUSA LIMA6   1Laboratório de Engenharia Agrícola – LEAG, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Av. Alberto Laqmedo, 2000, Parque Califórnia, Campos dos Goytacazes, RJ, Brasil, [email protected] 2Laboratório de Engenharia Agrícola – LEAG, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Av. Alberto Laqmedo, 2000, Parque Califórnia, Campos dos Goytacazes, RJ, Brasil, [email protected]  3Laboratório de Engenharia Agrícola – LEAG, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Av. Alberto Laqmedo, 2000, Parque Califórnia, Campos dos Goytacazes, RJ, Brasil, [email protected]  4Laboratório de Engenharia Agrícola – LEAG, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Av. Alberto Laqmedo, 2000, Parque Califórnia, Campos dos Goytacazes, RJ, Brasil, [email protected]  5Laboratório de Engenharia Agrícola – LEAG, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Av. Alberto Laqmedo, 2000, Parque Califórnia, Campos dos Goytacazes, RJ, Brasil, [email protected]  6Laboratório de Engenharia Agrícola – LEAG, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Av. Alberto Laqmedo, 2000, Parque Califórnia, Campos dos Goytacazes, RJ, Brasil, [email protected]     1 RESUMO   Na atividade cafeeira, o Brasil se destaca como maior produtor mundial, porém verifica-se que a sua produtividade é afetada de forma negativa pela seca, o que torna a produção dependente de complementação hídrica. Este trabalho tem como objetivo determinar estresse hídrico e o desenvolvimento do café Conilon em diferentes lâminas de irrigação. O delineamento experimental foi constituído de blocos casualizados, com três repetições, distribuídos em cinco tratamentos, sendo estes as lâminas de água de 0, 25, 50, 100 e 125% da ET0­. Cada parcela foi constituída de seis plantas, sendo as duas primeiras plantas de cada bloco consideradas bordadura. O potencial hídrico foliar foi determinado pela  medição da pressão de turgescência da folha, utilizando a bomba de Scholander, em uma planta por bloco e por tratamento. A altura da planta, secção transversal do caule e diâmetro da copa foram avaliados em três plantas por bloco, utilizando régua e paquímetro graduados. Os valores para o potencial hídrico foliar realizado na antemanhã variaram ente –0,15 a -1,18 MPa e, ao meio dia, de -1,17 a -2,3 MPa. As lâminas de irrigação equivalentes a 100 e 125% da ET0 apresentaram maiores valores ao longo do desenvolvimento da cultura até o momento da avaliação.    Palavras-Chave: cafeeiro, bomba de Scholander, status hídrico, parâmetros biométricos.     FURLAN, D. A.; SOUSA, E.F.; MENDONÇA, J. C.; SOUZA, C. L. M.; GOTTARDO, R. D.  E LIMA, R. A. S. POTENTIAL LEAF WATER AND VEGETATIVE DEVELOPMENT OF COFFEE CONILON UNDER DIFFERENT IRRIGATION DEPTHS IN THE REGION OF CAMPOS DOS GOYTACAZES - RJ     2 ABSTRACT   In the coffee production, Brazil stands out as the world's largest producer, but its productivity is negatively affected by drought, which makes production dependent on water supplementation. This work aims to determine water stress and the development of Conilon coffee in different irrigation depths. The experimental design consisted of randomized blocks with three replicates, distributed in five treatments, the irrigation depths of 0, 25, 50, 100 and 125% of ET0 -. Each plot was constituted of six plants, being the first two plants of each block considered border. The leaf water potential was is determined by measuring leaf turgor pressure using the Scholander pump in a plant per block and by treatment. The plant height, stem cross-section and crown diameter were evaluated in three plants per block using a graduated ruler and pachymeter. The values ​​for leaf water potential performed in the morning ranged from -0.15 to -1.18 MPa and, for noon, from -1.17 to -2.3 MPa. The irrigation depths equivalent to 100 and 125% of the ET0 presented higher values ​​throughout the development of the culture until the moment of the evaluation.   Keywords: coffee, Scholander pump, water status, biometric parameters.

scholarly journals 275 Water Relations of Fruit Cracking in Single-truss Tomato Plants

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 489E-489
Author(s):  
Takashi Ikeda ◽  
Kunio Okano ◽  
Yuka Sakamoto ◽  
Shin-ichi Watanabe
Keyword(s):  
Water Potential ◽  
Water Relations ◽  
Water Status ◽  
Potential Gradient ◽  
Culture Solution ◽  
Tomato Plants ◽  
Fruit Flesh ◽  
Fruit Cracking ◽  
Fruit Skin ◽  
Water Potential Gradient

This study was undertaken to investigate the water relations of tomato (Lycopersicon esculentum Mill.) fruit cracking for single-truss tomato plants. The tomato plants were cultured on a closed hydroponic system in greenhouse. Water status of culture solution and plant tissues was measured with psychrometers. Water potential of the culture solution for the stressed plant was changed from -0.06 MPa (control plants) to -0.36 MPa at 24 days after anthesis. Hardness of the fruit skin was not different significantly between the stressed plants and the control plants. Fruit cracking occurred frequently in the control plants, but not in the stressed plants. Water potential gradient between the tissue of fruit flesh and water source for the control plants was bigger than that of the stressed plants. Turgors were increased at the tissues of fruit flesh and fruit skin at the control plants between predawn and morning but not at the stressed plants. These results indicated that the water potential gradient and the increased turgor in these tissues might be a trigger for the occurrence of fruit cracking on single-truss tomato plants.

scholarly journals Water Relations of Field-grown Quercus virginiana Mill. from Preharvest through Containerization and 1 Year into a Landscape

1994 ◽  
Vol 119 (2) ◽  
pp. 169-174 ◽  
Author(s):  
R.C. Beeson
Keyword(s):  
Growth Rate ◽  
Water Potential ◽  
Water Relations ◽  
Water Status ◽  
Root Pruning ◽  
Quercus Virginiana ◽  
Live Oak ◽  
Transplant Shock ◽  
Oak Trees ◽  
Landscape Water

Large (≈5 m high) Quercus virginiana Mill. (live oak) trees produced in 0.64-m-diameter in-ground fabric containers were root pruned or not root pruned inside containers before harvest. Harvested trees were grown in two sizes of polyethylene containers for 10 months, then transplanted into a landscape. Water potential (ψT) of small branches (<4 mm in diameter) was measured diurnally during containerization and for 1 year in the landscape. Root pruning had no influence on postharvest survival. Neither root pruning nor container size affected tree water status during containerization or in the landscape. All surviving trees recovered from transplant shock following harvest after 16 weeks in a container, independent of treatment. In the landscape, 35 weeks of daily irrigation were required before dusk ψT declined to within 0.1 MPa of predawn values, a result indicating alleviation of transplant shock. Trunk growth rate during containerization was highest in larger containers. However, in the landscape, root pruning and small containers were associated with higher trunk growth rate. Tree water status during containerization and in the landscape is discussed.

scholarly journals Water relations of field-grown grapevines in the São Francisco Valley, Brazil, under different rootstocks and irrigation strategies

2009 ◽  
Vol 66 (4) ◽  
pp. 436-446 ◽  
Author(s):  
Claudia Rita de Souza ◽  
Luís Henrique Bassoi ◽  
José Moacir Pinheiro Lima Filho ◽  
Fabrício Francisco Santos da Silva ◽  
Leandro Hespanhol Viana ◽  
...  
Keyword(s):  
Water Potential ◽  
Root System ◽  
Water Relations ◽  
Leaf Water Potential ◽  
Water Status ◽  
Irrigation Management ◽  
Leaf Water ◽  
Stem Water Potential ◽  
Area Index ◽  
Grape Quality

There is an increased demand for high quality winegrapes in the São Francisco Valley, a new wine producing area in Brazil. As the grape quality is closely linked to the soil water status, understanding the effects of rootstock and irrigation management on grapevine water relations is essential to optimize yield and quality. This study was carried out to investigate the effects of irrigation strategies and rootstocks on water relations and scion vigour of field-grown grapevines in Petrolina, Pernambuco state, Brazil. The cultivars used as scions are Moscato Canelli and Syrah, both grafted onto IAC 572 and 1103 Paulsen rootstocks. The following water treatments were used: deficit irrigation, with holding water after veraison; and partial root-zone drying, supplying (100% of crop evapotranspiration) of the water loss to only one side of the root system after fruit set, alternating the sides periodically (about 24 days). In general, all treatments had values of pre-dawn leaf water potential higher than -0.2 MPa, suggesting absence of water stress. The vine water status was more affected by rootstock type than irrigation strategies. Both cultivars grafted on IAC 572 had the highest values of midday leaf water potential and stem water potential, measured on non-transpiring leaves, which were bagged with both plastic sheet and aluminum foil at least 1 h before measurements. For both cultivars, the stomatal conductance (g s), transpiration (E) and leaf area index (LAI) were also more affected by roostsotck type than by irrigation strategies. The IAC 572 rootstock presented higher g s, E and LAI than the 1103 Paulsen. Differences in vegetative vigor of the scion grafted onto IAC 572 rootstocks were related to its higher leaf specific hydraulic conductance and deeper root system as compared to the 1103 Paulsen, which increased the water-extraction capability, resulting in a better vine water status.

Water relations and yield inAzospirillum-inoculated wheat exposed to drought in the field

2004 ◽  
Vol 82 (2) ◽  
pp. 273-281 ◽  
Author(s):  
Cecilia M Creus ◽  
Rolando J Sueldo ◽  
Carlos A Barassi
Keyword(s):  
Grain Yield ◽  
Water Potential ◽  
Water Content ◽  
Water Relations ◽  
Relative Water Content ◽  
Mineral Content ◽  
Water Status ◽  
Water Fraction ◽  
Relative Water ◽  
And Control

There are scarce data connecting water relations in Azospirillum-inoculated wheat suffering drought during anthesis with the yield and mineral content of grains. Azospirillum brasilense Sp245-inoculated seeds of Triticum aestivum 'Pro INTA Oasis' were sown in nonirrigated and control plots. Water potential, water content, and relative water content were determined on flag leaves. Plant water status was calculated from pressure–volume curves. At maturity, grain yield and its components were determined. P, Ca, Mg, K, Fe, Cu, and Zn were determined in dried grains. Even though the cultivar underwent osmotic adjustment, significantly higher water content, relative water content, water potential, apoplastic water fraction, and lower cell wall modulus of elasticity values were obtained in Azospirillum-inoculated plants suffering drought. Grain yield loss to drought was 26.5% and 14.1% in noninoculated and Azospirillum-inoculated plants, respectively. Grain Mg and K diminished in nonirrigated, noninoculated plots. However, grains harvested from Azospirillum-inoculated plants had significantly higher Mg, K, and Ca than noninoculated plants. Neither drought nor inoculation changed grain P, Cu, Fe, and Zn contents. A better water status and an additional "elastic adjustment" in Azospirillum-inoculated wheat plants could be crucial in promoting higher grain yield and mineral quality at harvest, particularly when drought strikes during anthesis.Key words: Azospirillum, wheat, drought, pressure–volume curves, yield, mineral content.

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