Water transport and leaf water relations in winter wheat crops
Leaf water potential (psiL) in winter wheat (Triticum aestivum L cv Huntsman) was related to crop evaporation rate and soil water potential. During the day psiL responded primarily to changes in evaporation, whereas seasonal changes in psiL resulted from changes in soil water potential. Hysteresis i...
| Main Author: | |
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| Format: | Thesis (University of Nottingham only) |
| Language: | English |
| Published: |
1978
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| Online Access: | https://eprints.nottingham.ac.uk/12599/ |
| _version_ | 1848791536890806272 |
|---|---|
| author | Wallace, James S. |
| author_facet | Wallace, James S. |
| author_sort | Wallace, James S. |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | Leaf water potential (psiL) in winter wheat (Triticum aestivum L cv Huntsman) was related to crop evaporation rate and soil water potential. During the day psiL responded primarily to changes in evaporation, whereas seasonal changes in psiL resulted from changes in soil water potential.
Hysteresis in the relation between psiL and the flow of water through the plants was attributed to changes in water storage in the soil-plant system. Modelling this gave estimates of the hydraulic resistance (R) and capacitance (C) of the soil-plant system which agreed with independent estimates.
Components of R and C were also estimated. Then the soil water potential (psiS) was high, the largest hydraulic resistance could be atrributed to the soil-root system, the stem resistance was half of this. Resistance to water flow in the soil-root system increased when psiS was low, and there was evidence of large water potential gradients in the soil around the roots.
There was a systematic decrease in leaf osmotic potential (psiPi) and increase in leaf turgor potential (psiP, ) from the bottom to the top of the stem. When psiL in the youngest leaves decreased so did psiPi, apparently by a combination of dehydration and solute accumulation in the leaves. Osmotic adaptation therefore tended to maintain psiP during water stress. Maintenance of psiP was important since stomatal conductance was reduced at low-leaf turgor potentials, irrespective of irradiance. |
| first_indexed | 2025-11-14T18:30:05Z |
| format | Thesis (University of Nottingham only) |
| id | nottingham-12599 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-14T18:30:05Z |
| publishDate | 1978 |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-125992025-02-28T11:20:13Z https://eprints.nottingham.ac.uk/12599/ Water transport and leaf water relations in winter wheat crops Wallace, James S. Leaf water potential (psiL) in winter wheat (Triticum aestivum L cv Huntsman) was related to crop evaporation rate and soil water potential. During the day psiL responded primarily to changes in evaporation, whereas seasonal changes in psiL resulted from changes in soil water potential. Hysteresis in the relation between psiL and the flow of water through the plants was attributed to changes in water storage in the soil-plant system. Modelling this gave estimates of the hydraulic resistance (R) and capacitance (C) of the soil-plant system which agreed with independent estimates. Components of R and C were also estimated. Then the soil water potential (psiS) was high, the largest hydraulic resistance could be atrributed to the soil-root system, the stem resistance was half of this. Resistance to water flow in the soil-root system increased when psiS was low, and there was evidence of large water potential gradients in the soil around the roots. There was a systematic decrease in leaf osmotic potential (psiPi) and increase in leaf turgor potential (psiP, ) from the bottom to the top of the stem. When psiL in the youngest leaves decreased so did psiPi, apparently by a combination of dehydration and solute accumulation in the leaves. Osmotic adaptation therefore tended to maintain psiP during water stress. Maintenance of psiP was important since stomatal conductance was reduced at low-leaf turgor potentials, irrespective of irradiance. 1978 Thesis (University of Nottingham only) NonPeerReviewed application/pdf en arr https://eprints.nottingham.ac.uk/12599/1/476343.pdf Wallace, James S. (1978) Water transport and leaf water relations in winter wheat crops. PhD thesis, University of Nottingham. |
| spellingShingle | Wallace, James S. Water transport and leaf water relations in winter wheat crops |
| title | Water transport and leaf water relations in winter wheat crops |
| title_full | Water transport and leaf water relations in winter wheat crops |
| title_fullStr | Water transport and leaf water relations in winter wheat crops |
| title_full_unstemmed | Water transport and leaf water relations in winter wheat crops |
| title_short | Water transport and leaf water relations in winter wheat crops |
| title_sort | water transport and leaf water relations in winter wheat crops |
| url | https://eprints.nottingham.ac.uk/12599/ |