Within-crown variation in leaf conductance of Norway spruce: 
effects of irradiance, vapour pressure deficit, leaf water status 
and plant hydraulic constraints

Application of a low-relative-humidity treatment (LHT) to seedlings can reduce water stress on cuttings harvested from the seedlings, after the cuttings are planted. Effects of illumination during LHT and LHT duration on leaf water potential and leaf conductance in cucumber (Cucumis sativus L.) seedlings used as the model plant material and on growth of harvested cuttings were investigated to determine optimal LHT conditions. The seedlings received LHT for 12 or 24 h in a lighted or dark growth chamber at air temperatures of 28 to 31 °C and relative humidity of 12% to 25%. Cuttings including a foliage leaf and two cotyledons were harvested by cutting the hypocotyl of the seedlings immediately after the treatment, and then the cuttings were planted in vermiculite medium. Four days after planting, the total fresh weight of the cuttings from seedlings that had received LHT in the lighted chamber was 2.2 times that of cuttings from seedlings that had not received LHT, whereas the total fresh weight of those that had received LHT in the dark increased by 1.3 to 1.8 times. Significant effects of illumination during LHT were also observed in the transpiration rate and growth of the cuttings, harvested following the treatment, after they were planted. By varying LHT duration, it was also found that leaf water potential and leaf conductance of the seedlings decreased as LHT duration increased up to 18 h. Thus, illumination during LHT increased the growth of cuttings taken following the treatment, and optimal treatment duration of around 18 h was estimated from the seedlings' leaf conductance and leaf water potential.

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Leaf Conductance and Leaf Water Status of Sesame Strains in Hot, Dry Climates 1

Crop Science ◽

10.2135/cropsci1975.0011183x001500060015x ◽

1975 ◽

Vol 15 (6) ◽

pp. 789-793 ◽

Cited By ~ 3

Author(s):

A. E. Hall ◽

D. M. Yermanos

Keyword(s):

Water Status ◽

Leaf Conductance ◽

Leaf Water ◽

Leaf Water Status ◽

Dry Climates

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Drought Effects on Transpiration and Leaf Water Status of Cowpea in Controlled Environments

Functional Plant Biology ◽

10.1071/pp9800141 ◽

1980 ◽

Vol 7 (2) ◽

pp. 141 ◽

Cited By ~ 19

Author(s):

AE Hall ◽

E Schulze

Keyword(s):

Leaf Area ◽

Water Status ◽

Vapour Pressure Deficit ◽

Pressure Chamber ◽

Leaf Water ◽

Drought Treatment ◽

Leaf Water Status ◽

Unit Leaf ◽

Drought Avoidance ◽

Controlled Environments

The factors responsible for the extreme drought avoidance of cowpeas [Vigna unguiculata (L.) Walp.] previously observed in several field environments were investigated. Drought avoidance is defined as the extent to which high plant water potentials are maintained in the presence of environmental drought. Cowpeas were grown in controlled environments and subjected to either frequent irrigation or progressive drought. Plants in the drought treatment were grown for up to 2 months on 2-2.5 litres per plant of available water supplied 5 days after emergence. Transpiration of whole plants was determined by pot weighing, and leaf water status was determined with a pressure chamber. Well watered cowpeas avoided drought by two mechanisms: by avoiding water loss, because at constant air temperature transpiration increased only slightly with increases in vapour pressure deficit from 20 to 40 mbar; and due to an efficient water transport system which resulted in only small decreases in pressure chamber values with increases in transpiration at high rates of transpiration. Non-irrigated cowpeas avoided drought by maintaining low transpiration rates due to reduced leaf area and reduced transpiration per unit leaf area compared with irrigated plants.

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The dependence of water potential in shoots of <i>Picea abies</i> on air and soil water status

Annales Geophysicae ◽

10.1007/s00585-998-0470-6 ◽

1998 ◽

Vol 16 (4) ◽

pp. 470-476 ◽

Cited By ~ 6

Author(s):

A. Sellin

Keyword(s):

Picea Abies ◽

Water Potential ◽

Soil Water ◽

Vapour Pressure ◽

Water Status ◽

Vapour Pressure Deficit ◽

Plant Ecology ◽

Evaporative Demand ◽

Leaf Water Status ◽

Water Losses

Abstract. Where there is sufficient water storage in the soil the water potential (Ψx) in shoots of Norway spruce [Picea abies (L.) Karst.] is strongly governed by the vapour pressure deficit of the atmosphere, while the mean minimum values of Ψx usually do not drop below –1.5 MPa under meteorological conditions in Estonia. If the base water potential (Ψb) is above –0.62 MPa, the principal factor causing water deficiency in shoots of P. abies may be either limited soil water reserves or atmospheric evaporative demand depending on the current level of the vapour pressure deficit. As the soil dries the stomatal control becomes more efficient in preventing water losses from the foliage, and the leaf water status, in turn, less sensitive to atmospheric demand. Under drought conditions, if Ψb falls below –0.62 MPa, the trees' water stress is mainly caused by low soil water availability. Further declines in the shoot water potential (below –1.5 MPa) can be attributed primarily to further decreases in the soil water, i.e. to the static water stress.Key words. Hydrology (evapotranspiration · plant ecology · soil moisture).

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Employment of artificial neural networks for non-invasive estimation of leaf water status using color features: a case study in Spathiphyllum wallisii

Acta Physiologiae Plantarum ◽

10.1007/s11738-021-03244-y ◽

2021 ◽

Vol 43 (5) ◽

Author(s):

Amin Taheri-Garavand ◽

Abdolhossein Rezaei Nejad ◽

Dimitrios Fanourakis ◽

Soodabeh Fatahi ◽

Masoumeh Ahmadi Majd

Keyword(s):

Neural Networks ◽

Artificial Neural Networks ◽

Water Status ◽

Leaf Water ◽

Leaf Water Status ◽

Non Invasive ◽

Color Features ◽

Artificial Neural

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Visual estimation of plant water status in cereals

The Journal of Agricultural Science ◽

10.1017/s0021859600060524 ◽

1979 ◽

Vol 92 (1) ◽

pp. 83-89 ◽

Cited By ~ 13

Author(s):

H. G. Jones

Keyword(s):

Spring Wheat ◽

Water Status ◽

Plant Morphology ◽

Leaf Water ◽

Plant Water Status ◽

Plant Water ◽

Visual Estimation ◽

Leaf Water Status ◽

Visual Scoring ◽

Breeding Programmes

SummaryThe potential offered for plant breeding programmes by visual scoring techniques for plant water status was investigated in rice and spring wheat. It was found that differing plant morphology could seriously bias visual estimates of leaf water potential, particularly in spring wheat. In spite of this problem, it was found that at least for rice, this type of approach may have potential in future breeding programmes where an estimate of leaf water status is required, such as those for drought tolerance, so long as a high intensity of selection is not necessary.

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