Night-time sap flow is parabolically linked to midday water potential for field-grown almond trees

SUMMARYAlmond trees (Amygdalus communis L. cvs Garrigues and Ramillete) were grown in the field under non-irrigated conditions in Murcia, Spain. Seasonal variations in leaf water potential components were studied in 1989. Predawn leaf water potential showed high values in both cultivars, due to the absence of soil water stress. Pressure-volume curve analysis indicated that the leaf osmotic potential at full saturation (Ψo(sat)) for cv. Garrigues remained fairly constant throughout the season. Bulk modulus of elasticity (E) showed, in both cultivars, a tendency to decrease as the season progressed. E values were higher in Ramillete than in Garrigues. The relative water content at the turgor loss point (RWCtlp) seemed to be controlled by E values. The larger relative apoplastic water content (RWCa found in Ramillete might have allowed it to retain more water at low leaf water potentials than Garrigues. These facts would support the suggestion that Ramillete is a more drought-resistant cultivar than Garrigues.

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Water potential and sap flow rate in adult trees with moist and dry soil as used for the assessment of root system depth

Biologia Plantarum ◽

10.1007/bf02878125 ◽

1980 ◽

Vol 22 (1) ◽

pp. 34-41 ◽

Cited By ~ 28

Author(s):

J. Čermák ◽

J. Huzulák ◽

M. Penka

Keyword(s):

Water Potential ◽

Root System ◽

Flow Rate ◽

Sap Flow ◽

Adult Trees ◽

Dry Soil

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Relationships Between Climatic Variables and Sap Flow, Stem Water Potential and Maximum Daily Trunk Shrinkage in Lemon Trees

Plant and Soil ◽

10.1007/s11104-005-1302-z ◽

2006 ◽

Vol 279 (1-2) ◽

pp. 229-242 ◽

Cited By ~ 57

Author(s):

M. F. Ortuño ◽

Y. García-Orellana ◽

W. Conejero ◽

M. C. Ruiz-Sánchez ◽

O. Mounzer ◽

...

Keyword(s):

Water Potential ◽

Sap Flow ◽

Climatic Variables ◽

Stem Water Potential ◽

Stem Water

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INFLUENCE OF PREHARVEST IRRIGATION CUTOFF DURATION AND POSTHARVEST WATER DEPRIVATION IN ALMOND

HortScience ◽

10.21273/hortsci.25.9.1172b ◽

1990 ◽

Vol 25 (9) ◽

pp. 1172b-1172

Author(s):

David Goldhamer ◽

Mario Viveros ◽

Ken Shackel

Keyword(s):

Water Potential ◽

Water Deprivation ◽

Sandy Loam ◽

Prunus Dulcis ◽

Rooting Depth ◽

Kernel Size ◽

Predawn Leaf Water Potential ◽

Almond Trees ◽

Loam Soil ◽

Kernel Yield

Previously well irrigated mature `Nonpareil' almond trees (Prunus dulcis) were subjected to varying periods of water deprivation prior to harvest and then to either full or no postharvest irrigation. Eight preharvest water deprivation (PWD) lengths ranging from 14 to 63 days were evaluated on a sandy loam soil with a rooting depth of about 1.5 m.Development of tree water deficits occurred rapidly following PWD. Predawn leaf water potential decreased to about -1.8 and -3.1 MPa after 10 and 20 days, respectively. Defoliation began about 30 days after PWD and trees subjected to more than 50 days completely defoliated. The rate of hull split was directly related to the PWD duration. With early cutoffs, the size of the hull split-arrested nuts at harvest was large compared with the same nut type in later cutoffs suggesting that as nuts develop, large nuts are preferential sinks for assimilates. Kernel size was only mildly reduced by PWD during the first study year. There was a trend toward lower total kernel yield with longer PWD as a result of smaller kernel girth but yield differences were not significant. The number of nuts remaining in the tree after shaking was not related to PWD. Bark strength increased after PWD with 10 to 14 days required to prevent shaker damage. Postharvest irrigation resulted in late season defoliation but no rebloom. Bloom density reductions in 1990 were related more to the lack of 1989 postharvest irrigation than to early PWD.

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Tree water relations trigger monoterpene emissions from Scots pine stem during spring recovery

Biogeosciences Discussions ◽

10.5194/bgd-12-7783-2015 ◽

2015 ◽

Vol 12 (10) ◽

pp. 7783-7814 ◽

Cited By ~ 1

Author(s):

A. Vanhatalo ◽

T. Chan ◽

J. Aalto ◽

J. F. Korhonen ◽

P. Kolari ◽

...

Keyword(s):

Organic Compounds ◽

Scots Pine ◽

Sap Flow ◽

Environmental Drivers ◽

Diurnal Pattern ◽

Night Time ◽

Tree Diameter ◽

Tree Canopies ◽

Volatile Organic ◽

Winter Time

Abstract. Tree canopies are known to emit large amounts of VOCs (volatile organic compounds) such as monoterpenes to the surrounding air. The main source for these is considered to be the green biomass, i.e. foliage, but emissions from the woody compartments have not been quantified. A VOC emission anomaly has been observed during transition from winter to summer activity. We analyzed if non-foliar components could partially explain the anomaly. We measured the VOC emissions from Scots pine (Pinus sylvestris L.) stems and shoots during the dehardening phase of trees in field conditions in two consecutive springs. We observed a large, transient monoterpene burst from stems, while the shoot monoterpene emissions and transpiration remained low. The burst lasted about 12 h. Simultaneously, an unusual night-time sap flow and an anomalous diurnal pattern of tree diameter were detected. Hence, we suggest that the monoterpene burst was a consequence of the recovery of the stem from winter-time. This indicates that the dominant processes and environmental drivers triggering the monoterpene emissions are different between stems and foliage.

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Water Relations of Acer rubrum in Response to Summer Digging

HortScience ◽

10.21273/hortsci.32.4.595c ◽

1997 ◽

Vol 32 (4) ◽

pp. 595C-595

Author(s):

P.R. Knight ◽

J.R. Harris ◽

J.K. Fanelli ◽

M.P. Kelting

Keyword(s):

Stomatal Conductance ◽

Water Potential ◽

Water Relations ◽

Leaf Water Potential ◽

Sap Flow ◽

Acer Rubrum ◽

Leaf Water ◽

Xylem Embolism ◽

Ball Diameter ◽

Old Trees

Two experiments were conducted on Acer rubrum L. to determine the influence of root severance on sap flow, stomatal conductance, leaf water potential (ψ), and stem xylem embolism. Experiment 1 utilized 3-year-old trees, and experiment 2 utilized 2-year-old trees. Sixteenmm sap flow gauges were installed on both groups. Trees for experiment 1 were harvested on 31 May 1996 with a root ball diameter of 30.5 cm. Sap flow was reduced within one day after plants were harvested and was still lower 1 week after harvest. On 7 June 1996, harvested trees had lower stomatal conductance measurements, compared to not-harvested trees, but ψ were similar. A second experiment was initiated on 20 Aug. 1996, using the same protocol as in experiment 1. Sap flow was reduced within 2 h after harvest for harvested trees compared to not-harvested trees. Leaf stomatal conductances were reduced within 4 h of harvest. Leaf water potentials were not influenced on the day that the trees were harvested. Embolism levels were increased by harvest within 24 h. These results indicate that transplant stress begins shortly after harvest and not at the actual time of transplant.

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