An Analysis of the Effects of Repeated Short-Term Soil Water Deficits on Stomatal Conductance to Carbon Dioxide and Leaf Photosynthesis by the Legume Macroptilium atropurpureum Cv. Siratro

1981 ◽  
Vol 8 (3) ◽  
pp. 347 ◽  
Author(s):  
MJ Fisher ◽  
DA Charles-Edwards ◽  
MM Ludlow
Keyword(s):  
Stomatal Conductance ◽  
Water Potential ◽  
Soil Water ◽  
Water Deficit ◽  
Leaf Water Potential ◽  
Leaf Water ◽  
Mathematical Function ◽  
Leaf Photosynthesis ◽  
Short Term ◽  
Macroptilium Atropurpureum

The response was measured of stomatal conductance and leaf photosynthesis to changing leaf water potential in the legume siratro subjected to a sequence of I-week cycles of increasing soil water deficit followed by watering. The response of stomatal conductance was described using a continuous mathematical function, which is more robust and accurate than the usual discontinuous linear function used to analyse such data. After seven successive cycles of water deficit, there was no apparent adjustment of the short-term response of leaf conductance to leaf water potential.

scholarly journals Water status and gas exchange of umbu plants (Spondias tuberosa Arr. Cam.) propagated by seeds and stem cuttings

2007 ◽  
Vol 29 (2) ◽  
pp. 355-358 ◽  
Author(s):  
José Moacir Pinheiro Lima Filho
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Water Potential ◽  
Soil Water ◽  
Water Deficit ◽  
Leaf Water Potential ◽  
Leaf Gas Exchange ◽  
Leaf Water ◽  
Soil Water Deficit ◽  
Stem Cuttings

The experiment was carried out at the Embrapa Semi-Árido, Petrolina-PE, Brazil, in order to study the physiological responses of umbu plants propagated by seeds and by stem cuttings under water stress conditions, based on leaf water potential and gas exchange measurements. Data were collected in one-year plants established in pots containing 30 kg of a sandy soil and submitted to twenty-day progressive soil water deficit. The evaluations were based on leaf water potential and gas exchange data collection using psychrometric chambers and a portable infra-red gas analyzer, respectively. Plants propagated by seeds maintained a significantly higher water potential, stomatal conductance, transpiration and photosynthesis under decreasing soil water availability. However, plants propagated by stem cuttings were unable to maintain a favorable internal water balance, reflecting negatively on stomatal conductance and leaf gas exchange. This fact is probably because umbu plants propagated by stem cuttings are not prone to formation of root tubers which are reservoirs for water and solutes. Thus, the establishing of umbu plants propagated by stem cuttings must be avoided in areas subjected to soil water deficit.

Relationship Between Root/Soil Hydraulic Properties and Stomatal Behaviour in Sugarcane

1989 ◽  
Vol 16 (3) ◽  
pp. 241 ◽  
Author(s):  
NZ Saliendra ◽  
FC Meinzer
Keyword(s):  
Stomatal Conductance ◽  
Water Potential ◽  
Soil Water ◽  
Leaf Water Potential ◽  
Water Status ◽  
Hydraulic Conductance ◽  
Leaf Water ◽  
Soil Drying ◽  
Root Hydraulic Conductance ◽  
High Soil Moisture

Stomatal conductance, leaf and soil water status, transpiration, and apparent root hydraulic conductance were measured during soil drying cycles for three sugarcane cultivars growing in containers in a greenhouse. At high soil moisture, transpiration and apparent root hydraulic conductance differed considerably among cultivars and were positively correlated, whereas leaf water potential was similar among cultivars. In drying soil, stomatal and apparent root hydraulic conductance approached zero over a narrow (0.1 MPa) range of soil water suction. Leaf water potential remained nearly constant during soil drying because the vapor phase conductance of the leaves and the apparent liquid phase conductance of the root system declined in parallel. The decline in apparent root hydraulic conductance with soil drying was manifested as a large increase in the hydrostatic pressure gradient between the soil and the root xylem. These results suggested that control of stomatal conductance in sugarcane plants exposed to drying soil was exerted primarily at the root rather than at the leaf level.

The recovery of leaf water potential following burning of two droughted tropical pasture species

1978 ◽  
Vol 18 (92) ◽  
pp. 423 ◽  
Author(s):  
MJ Fisher
Keyword(s):  
Stomatal Conductance ◽  
Water Potential ◽  
Soil Water ◽  
Leaf Water Potential ◽  
Management Practice ◽  
Leaf Water ◽  
Tropical Pasture ◽  
Native Pastures ◽  
Leaf Extension ◽  
Semi Arid

Following burning (day 0) of a water-stressed sward of green panic and siratro, measurements were made both on unburned plants and on regrowth of burned plants of leaf water potential (�s) and stomatal conductance (gs) at 1.00 p.m. and of leaf extension. In the unburned plants �s, remained low (-23 to -45 bar for green panic, and -14 to -18 bar for siratro), the stomata were closed and no growth occurred. In the burned plants of both species, however, �s on day 12 was -9 to -11 bars, the stomata were open and growth occurred, presumably because the complete defoliation allowed the plants to make use of a limited store of soil water at higher water potential. In green panic �s fell rapidly, and growth stopped after day 19, but �s and g, in siratro were still high on day 28. Burning of droughted native pastures is a common management practice in the semi-arid tropics of Australia. The data may explain how the pastures are able to make the new growth that frequently occurs.

A basis for improved soil and water management for irrigated pastures in northern Victoria

1988 ◽  
Vol 28 (3) ◽  
pp. 315 ◽  
Author(s):  
SJ Blaikie ◽  
FM Martin ◽  
WK Mason ◽  
DJ Connor
Keyword(s):  
Water Potential ◽  
Soil Water ◽  
Water Deficit ◽  
Leaf Water Potential ◽  
White Clover ◽  
Soil Profile ◽  
Leaf Water ◽  
Individual Species ◽  
Soil Water Deficit ◽  
Leaf Elongation

The water relations of white clover and paspalum as monocultures and components of a mixed pasture were studied on a normal and a modified soil profile during the interval between 2 successive irrigations. Responses of individual species were similar in monocultures and mixed pastures. On the normal profile white clover was the first species to react to soil water deficit when the rate of leaf elongation fell by 33% to about 10 mm/day after 30 mm of cumulative evaporation minus rainfall (E - R). This was followed by a reduction in dawn and midday leaf water potential at around 50 mm E - R. After 65 mm E - R, leaf elongation had ceased. In contrast, paspalum showed no signs of water shortage until 70-80 mm E - R. At this stage both the rate of leaf elongation and midday leaf water potential fell. After 90 mm E - R the dawn leaf water potential fell and by 120 mm E - R leaf elongation was negligible. Modification of the profile increased soil water availability by allowing more extraction of water at depth in the profile. This delayed the onset of water stress by about 40 mm E - R in both species. These observations show that the common irrigation interval of 60-90 mm E - R in northern Victoria is likely to restrict pasture yields because it causes a period of soil water deficit stress, especially for white clover, and the development of leaf area is impeded, increasing the time taken for canopies to recover maximum productivity after grazing. To overcome these limitations farmers will have to water more frequently or modify the soil profile to provide pastures with a better water supply.

scholarly journals SOIL AND LEAF WATER POTENTIAL OF QUERCUS SEMECARPIFOLIA AT PHULCHOWKI HILL, NEPAL

2014 ◽  
Vol 20 ◽  
pp. 115-121
Author(s):  
K. Poudyal
Keyword(s):  
Stomatal Conductance ◽  
Water Potential ◽  
Soil Water ◽  
Leaf Water Potential ◽  
Soil Water Potential ◽  
Adaptation Strategy ◽  
Leaf Water ◽  
Pure Stand ◽  
Natural Ecosystem ◽  
Quercus Semecarpifolia

Quercus semecarpifolia is a high altitude oak and dominant species of central Himalayan vegetation.In the central Himalaya, plants are subjected to a prolonged dry period, thus developing moisturestress. Soil water potential at 15 cm and 30 cm depth, predawn and midday leaf water potential andtheir relationship with stomatal conductance and phenological behaviour was studied at PhulchowkiHill, Kathmandu to evaluate the drought adaptation strategy of Q. semecarpifolia in a pure stand at2130 m elevation. The natural ecosystem of Himalayan region has a characteristic climatic pattern ofconcentrated rainfall and a prolonged dry season which have a strong effect on the adaptability of thisspecies. It maintained a high predawn leaf water potential (ΨL pd) and stomatal conductance (gw)despite low soil water Ψ and ΨL pd . Lowest Ψs and ΨL pd were observed in March 1999, when therewas almost no rain for five months. Mean ΨL pd and ΨL md were (–1.79 and –2.29 MPa, respectively).Patterns of ΨL pd and ΨL md correlated significantly with soil Ψ, and phenology as ΨL pd oftenincreased during leafing but not with gw.DOI: http://dx.doi.org/10.3126/eco.v20i0.11473ECOPRINT An International Journal of EcologyVol. 20, 2013page: 115-121

Potential role of soil moisture deficit in the distribution of Cakile edentula

1986 ◽  
Vol 64 (11) ◽  
pp. 2789-2791 ◽  
Author(s):  
R. Wayne Tyndall ◽  
Alan H. Teramura ◽  
Larry W. Douglass
Keyword(s):  
Stomatal Conductance ◽  
Water Potential ◽  
Soil Water ◽  
Leaf Water Potential ◽  
Soil Water Potential ◽  
Leaf Water ◽  
Moisture Deficit ◽  
Cakile Edentula ◽  
Survival And Growth

Soil water potential, leaf water potential, and stomatal conductance of Cakile edentula (Bigelow) Hooker were compared between beach and foredune habitats on Currituck Bank, North Carolina. All three variables were significantly lower on the foredune than on the beach. Low soil water potential on the foredune may contribute to low survival and growth inhibition by lowering leaf water potential and stomatal conductance.

Soybean (Glycine max) – Velvetleaf (Abutilon theophrasti) Interspecific Competition

Weed Science ◽  
1987 ◽  
Vol 35 (5) ◽  
pp. 647-653 ◽  
Author(s):  
Philip H. Munger ◽  
James M. Chandler ◽  
J. Tom Cothren ◽  
Frank M. Hons
Keyword(s):  
Glycine Max ◽  
Stomatal Conductance ◽  
Water Potential ◽  
Interspecific Competition ◽  
Soil Water ◽  
Leaf Water Potential ◽  
Abutilon Theophrasti ◽  
Leaf Water ◽  
Water Extraction ◽  
Soil Water Extraction

In a 2-yr field study conducted on a Weswood silt loam soil (Fluventic Ustochrepts), interspecific competition between soybeans [Glycine max(L.) Merr. ‘Hutton′] and velvetleaf (Abutilon theophrastiMedik. # ABUTH) resulted in greater than 40 and 50% reductions in soybean and velvetleaf seed yield, respectively. Leaf area index, number of mainstem nodes, total number of leaves, and plant dry weight of monocultured and intercropped velvetleaf differed significantly as early as 4 weeks after emergence. Interspecific competition had litttle or no effect on soybean morphology before 8 weeks after emergence. Soil water extraction occurred to 1-m depths in a monoculture of velvetleaf (five plants/m2) in 1984 and 1985. Monocultured soybeans (32.5 plants/m2) extracted water from a 1.5-m or greater depth of the soil profile during the same years. Soil water extraction in the intercropped plots resembled that of the monocultured velvetleaf treatment until soybeans attained R6, when soil water was extracted to a 1.5-m depth. The potential for interspecific competition for water existed early in the season before late-season soybean root development. Relative water content and leaf water potential (Ψw1) did not differ (0.05) between monocultured and intercropped soybeans in 1984 or 1985. In 1985, Ψw1differed between monocultured and intercropped velvetleaf during anthesis. Leaf water potential values in the youngest, fully expanded leaves were approximately 0.3 and 0.4 MPa lower during midmorning and midday hours, respectively, in intercropped and monocultured velvetleaf. Transpiration and stomatal conductance did not differ between monocultured and intercropped soybeans or velvetleaf at any time during 1984. Photosynthetic and transpiration rates, stomatal conductance, and Ψw1were lower in intercropped than in monocultured velvetleaf during anthesis in 1985, suggesting interspecific competition for soil water. Soybean water relations were not affected in either year. The data suggest that soybean yield reductions in soybean-velvetleaf interspecific competition are attributable to resource limitations other than water in south-central Texas.

scholarly journals Physiological effects of water deficit on two oil palm (Elaeis guineensis Jacq.) genotypes

2015 ◽  
Vol 33 (2) ◽  
pp. 164-173 ◽  
Author(s):  
Seyed Mehdi Jazayeri ◽  
Yurany Dayanna Rivera ◽  
Jhonatan Eduardo Camperos-Reyes ◽  
Hernán Mauricio Romero
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Water Potential ◽  
Water Deficit ◽  
Leaf Water Potential ◽  
Oil Palm ◽  
Photosynthetic Capacity ◽  
Elaeis Guineensis ◽  
Leaf Water ◽  
Physiological Effects

Water supply is the main limiting factor that affects oil palm (Elaeis guineensis Jacq.) yield. This study aimed to evaluate the gas exchange and photosynthetic capacity, determine the physiological effects and assess the tolerance potential of oil palm genotypes under water-deficit conditions. The two oil palm commercial genotypes IRHO1001 and IRHO7010 were exposed to soil water potentials of -0.042 MPa (field capacity or well-watered) or -1.5 MPa (drought-stressed). The leaf water potential and gas exchange parameters, including photosynthesis, stomatal conductance, transpiration and water use efficiency (WUE), as well as the photosynthesis reduction rate were monitored at 4 and 8 weeks after treatment. The IRHO7010 genotype showed fewer photosynthesis changes and a smaller photosynthetic reduction under the prolonged water deficit conditions of 23% at 4 weeks after the treatment as compared to 53% at 8 weeks after treatment, but the IRHO1001 genotype showed 46% and 74% reduction at the two sampling times. 'IRHO7010' had a higher stomatal conductance and transpiration potential than 'IRHO1001' during the water shortage. The WUE and leaf water potential were not different between the genotypes during dehydration. The data suggested that 'IRHO7010' had a higher photosynthetic capacity during the drought stress and was more drought-tolerant than 'IRHO1001'.

scholarly journals Effects of Water Deficits on Prosopis tamarugo Growth, Water Status and Stomata Functioning

Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 53
Author(s):  
Alson Time ◽  
Edmundo Acevedo
Keyword(s):  
Stomatal Conductance ◽  
Water Potential ◽  
Leaf Area ◽  
Water Deficit ◽  
Leaf Water Potential ◽  
Growth Parameters ◽  
Water Status ◽  
Co2 Assimilation ◽  
Leaf Water ◽  
Ww Ii

The effect of water deficit on growth, water status and stomatal functioning of Prosopis tamarugo was investigated under controlled water conditions. The study was done at the Antumapu Experiment Station of the University of Chile. Three levels of water stress were tested: (i) well-watered (WW), (ii) medium stress intensity (low-watered (LW)) and (iii) intense stress (non-watered (NW)), with 10 replicates each level. All growth parameters evaluated, such as twig growth, specific leaf area and apical dominance index, were significantly decreased under water deficit. Tamarugo twig growth decreased along with twig water potential. The stomatal conductance and CO2 assimilation decreased significantly under the water deficit condition. Tamarugo maintained a high stomatal conductance at low leaf water potential. In addition, tamarugo reduced its leaf area as a strategy to diminish the water demand. These results suggest that, despite a significant decrease in water status, tamarugo can maintain its growth at low leaf water potential and can tolerate intense water deficit due to a partial stomatal closing strategy that allows the sustaining of CO2 assimilation in the condition of reduced water availability.

Sign in / Sign up

Export Citation Format

Share Document