scholarly journals Influence of Water Regimes and Potassium Chlorate on Floral Induction, Leaf Photosynthesis and Leaf Water Potential in Longan

2013 ◽  
Vol 5 (6) ◽  
Author(s):  
Chiti Sritontip ◽  
Pimsiri Tiyayon ◽  
Korawan Sringam ◽  
Sanchai Pantachod ◽  
Darunee Naphrom ◽  
...  
Keyword(s):  
Water Potential ◽  
Leaf Water Potential ◽  
Floral Induction ◽  
Leaf Water ◽  
Potassium Chlorate ◽  
Leaf Photosynthesis ◽  
Water Regimes ◽  
Influence Of Water

Photosynthesis Response of Sunlit and Shade Pepper (Capsicum annuum) Leaves at Different Positions in the Canopy Under Two Water Regimes

1994 ◽  
Vol 21 (3) ◽  
pp. 377 ◽  
Author(s):  
A Alvino ◽  
M Centritto ◽  
FD Lorenzi
Keyword(s):  
Water Potential ◽  
Capsicum Annuum ◽  
Leaf Water Potential ◽  
Co2 Exchange ◽  
Leaf Water ◽  
Predawn Leaf Water Potential ◽  
Water Regimes ◽  
Water Potentials ◽  
Sun And Shade ◽  
Shade Leaves

Pepper (Capsicum annuum L.) plants were grown in 1 m2 lysimeters under two different water regimes in order to investigate differences in the spatial arrangements of the leaves and to relate this to daily assimilation rates of leaves of the canopy. The control regime (well-watered (W) treatment) was irrigated whenever the accumulated 'A' pan evaporation reached 4 cm, whereas the water-stressed (S) treatment was watered whenever the predawn leaf water potential fell below -1 MPa. During the growing cycle, equal numbers of sun and shade leaves were chosen from the apical, middle and basal parts of the canopy, corresponding to groups of leaves of increasing age. The CO2 exchange rate (CER) was measured at 0830, 1230 and 1530 hours on 8 days along the crop cycle, on leaves in their natural inclination and orientation. Leaf water potentials were measured on apical leaves before dawn and concurrently with gas exchange measurements. Control plants maintained predawn leaf water potential at -0.3 MPa, but S plants reached values lower than -1.2 MPa. Midday leaf water potentials were about twice as low in the S plants as in the controls. Water stress reduced LA1 during the period of crop growth, and dry matter production at harvest. Stressed apical leaves appeared to reduce stress by changing their inclination. They were paraheliotropic around midday and diaheliotropic at 0830 and 1530 hours. The CER values of the S treatment were significantly lower than those of the W treatment in apical and middle leaves, whereas the CER of basal leaves did not differ in either treatments. In the S treatment, reduction in the CER values of sunlit apical leaves was more evident in the afternoon than at midday or early in the morning, whereas basal leaves were less affected by water than basal stress leaves if sunlit, and negligibly in shaded conditions.

INFLUENCE OF WATER STRESS CONDITIONING ON PHOTOSYNTHETIC WATER STRESS RESPONSE OF SWITCHGRASS (PANICUM VIRGATUM L.) AND TALL FESCUE (FESTUCA ARUNDINACEA SCHREB.)

2001 ◽  
Vol 49 (1) ◽  
pp. 15-24 ◽  
Author(s):  
Z. Kiss ◽  
D. D. Wolf
Keyword(s):  
Water Stress ◽  
Water Potential ◽  
Leaf Water Potential ◽  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Panicum Virgatum ◽  
Leaf Water ◽  
Panicum Virgatum L ◽  
Influence Of Water ◽  
Stress Cycles

The objective of this study was to investigate the influence of water stress conditioning on the photosynthesis response of switchgrass (Panicum virgatum L.) and tall fescue (Festuca arundinacea Schreb.) to moisture deficiency. Tillers of the two species were grown in the same, controlled, environment and were subjected to three conditioning water stress cycles, or were kept well watered. After drought conditioning all plants were subjected to moisture deficiency while photosynthesis and leaf water potential were monitored. Measurements were taken between –0.8 and –4.0 MPa and the rate of water stress was 0.49 MPa/day. The conditioning of switchgrass produced a 26% reduction in the photosynthesis rate during drought, while that of tall fescue produced a 57% reduction in photosynthesis. Both species maintained elongation and photosynthesis down to lower leaf water potentials after drought conditioning than before conditioning. The conditioning water stress cycles decreased the leaf conductance, mesophyll resistance and transpiration of tall fescue plants after rewatering. The leaf water potential of conditioned switchgrass plants was lower upon rewatering after three conditioning water stress cycles than the leaf water potential of non-conditioned plants, while the leaf conductance, mesophyll resistance and transpiration of conditioned and non-conditioned tillers were equal. These data indicate an improvement in the drought tolerance of tall fescue and switchgrass plants, emphasize the importance of knowing the previous water stress history of the plants in moisture deficiency experiments, and help to choose proper irrigation management for switchgrass and tall fescue.

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.

CHANGES IN LEAF WATER POTENTIAL, OSMOTIC ADJUSTMENT, AND PROLINE METABOLISM IN MULBERRY DURING WATER STRESS

1996 ◽  
Vol 44 (2-3) ◽  
pp. 135-141 ◽  
Author(s):  
B.D. Ranjitha Kumari ◽  
K. Veeranjaneyulu
Keyword(s):  
Water Stress ◽  
Amino Acid ◽  
Water Potential ◽  
Leaf Water Potential ◽  
Amino Acid Content ◽  
Leaf Water ◽  
Proline Metabolism ◽  
Proline Oxidase ◽  
Influence Of Water ◽  
Four Levels

The influence of water stress on amino acid content and proline metabolism was studied in 3-month-old mulberry plants at four levels of water stress. Leaf water potential and osmotic potential were significantly decreased in all stress treatments. Though leaf area and relative water content decreased, significantly, a marked decrease was observed only in severe stress treatment. Accumulation of total amino acids and proline was observed both in roots and leaves in stress treatments, with amino acid accumulation greater in leaves than in roots. In contrast, proline accumulation was greater in roots than in leaves. Activities of proline dehydrogenase and proline oxidase were inhibited under stress conditions. Inhibition of proline oxidase was greater in roots than in leaves.

scholarly journals ARABICA COFFEE CULTIVARS IN DIFFERENT WATER REGIMES IN THE CENTRAL CERRADO REGION

2019 ◽  
Vol 14 (3) ◽  
pp. 349
Author(s):  
Adriano Delly Veiga ◽  
Gustavo Costa Rodrigues ◽  
Omar Cruz Rocha ◽  
Gabriel Ferreira Bartholo ◽  
Antônio Fernando Guerra ◽  
...  
Keyword(s):  
Water Stress ◽  
Plant Growth ◽  
Grain Yield ◽  
Water Potential ◽  
Leaf Water Potential ◽  
Leaf Water ◽  
High Yield ◽  
Phenotypic Characterization ◽  
Arabica Coffee ◽  
Water Regimes

Phenotypic characterization of coffee cultivars under an irrigation system, as well as adaptability to controlled water stress, aiming at flowering uniformity, high yield and grain quality, plays an important role in coffee production in the cerrado areas. A field trial was carried out aiming to evaluate the agronomic performance of arabica coffee cultivars under different water regimes, using center pivot irrigation: irrigation throughout the year (WR1); suspended at the end of June for 40 days until leaf water potential reached -1.5 MPa (WR2); suspended at the end of June for 70 days until leaf water potential reached -2.3 MPa (WR3); suspended at the end of June for 100 days until leaf water potential reached -3.4 MPa (WR4); and a non-irrigated regime (WR5). The following traits were analyzed: plant height, stem diameter, canopy projection, number of plagiotropic branches, coffee grain yield, percentage of fruit in the cherry stage, and sieve retention percentages. Higher yield, plant growth, and percentage of fruit in the cherry stage are observed in the water regime with seventy days of controlled water stress (WR3). The Obatã IAC 1669-20 cultivar exhibits high yield and plant growth values in an irrigated system, and Catuaí Amarelo IAC 86 stands out in the non-irrigated system. For these genotypes, the coffee grain yield is most highly correlated with number of reproductive branches.

scholarly journals Leaf water potential meaning of different modalities of measurements

OENO One ◽  
2004 ◽  
Vol 38 (1) ◽  
pp. 15
Author(s):  
Alain Carbonneau ◽  
Alain Deloire ◽  
Pietro Costanza
Keyword(s):  
Water Potential ◽  
Leaf Water Potential ◽  
Leaf Water ◽  
Field Observations ◽  
Water Regimes ◽  
Water Potential Measurements

<p style="text-align: justify;">An experiment on Syrah in the Ecotron design of the AGRO Montpellier/INRA campus vineyard, with the control of different water regimes, allowed to test the physiological meaning and the field of application of different modalities of leaf water potential measurements : predawn and daily potential for leaves in a normal micro-environment (which keep all of their interest and generality), « stem » potential (which must be called differently and reserved to particular conditions) for shadow enveloped leaves. Field observations on Syrah and Merlot confirm the interest of some methods.</p>

High vapour pressure deficit results in a rapid decline of leaf water potential and photosynthesis of carrots grown on free-draining, sandy soils

2000 ◽  
Vol 51 (7) ◽  
pp. 839 ◽  
Author(s):  
Mark R. Gibberd ◽  
Neil C. Turner ◽  
Brian R. Loveys
Keyword(s):  
Water Potential ◽  
Water Content ◽  
Soil Water Content ◽  
Leaf Water Potential ◽  
Vapour Pressure ◽  
Warm Season ◽  
Vapour Pressure Deficit ◽  
Leaf Water ◽  
Leaf Photosynthesis ◽  
Growing Conditions

Two carrot (Daucus carota L.) genotypes (Nantes and Imperator) were grown in the field on a coarse-textured, sandy soil. Experiments were conducted over 2 consecutive seasons, one providing cool growing conditions and the other much warmer growing conditions during which the vapour pressure deficit was up to 2-fold higher than in the first season. Changes in growth, soil water content, and environmental conditions were monitored for both seasons, and diurnal measurements of leaf water potential and leaf photosynthesis were taken near maturity. Frequent irrigation maintained bulk soil water content above, or near, field capacity, with the sum of rainfall and irrigation exceeding potential evaporation by 1.4- and 1.3-fold during the cool and warm seasons, respectively. Even under such well-watered conditions, a large diurnal variation in leaf water potential (1200 and 1800 kPa for the cool- and warm-season crops, respectively) was recorded. During the cool season, withholding irrigation for up to 60 h resulted in further reductions in midday leaf water potential. However, there was no effect of withholding irrigation on leaf water potential during the warm season. During both seasons, leaf photosynthetic rate of well-watered plants peaked at around 20 µmol/m2.s in the early morning (0900 hours) and then decreased throughout the day, with the magnitude of the decline associated with the prevailing vapour pressure deficit. Under well-watered conditions, leaf water potential and photosynthesis were both negatively correlated with vapour pressure deficit, for both genotypes. Leaf water potential and photosynthesis were positively correlated with each other and we conclude that a high hydraulic resistance in the plant or soil results in a vapour pressure deficit-induced reduction in leaf water potential, which in turn reduces the rate of leaf photosynthesis.

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