Abstract
Sap pressure of cut tomato stems was monitored using a real-time (strict time constraint) data acquisition system to access changes in the root zone environment.Hydroponically grown tomato plants were cut, and a gas-free connection was made to a temperature-compensated pressure transducer.When plants were bathed in nutrient solution under isothermal conditions, pressure increased to a maximum within 10 to 75 minutes; maxima varied in the range of 20 kPa to 150 kPa.A fatigue phenomenon occurred with all plants, exhibited by decreases in pressure maxima over time as pressure cycles were repeated.When root zone aeration was stopped or a nitrogen atmosphere was used, pressure dropped following a lag of about 30 minutes.This decrease in pressure was partially reversible when aeration was resupplied.Near instantaneous changes in sap pressure occurred when the root zone was manipulated by imposing a temperature v gradient or by increasing the osmotic potential of the solution.The technique reported may be useful for determination of the role of changing root zone environments on sap flux and perhaps for assessment of the health status of plants.
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Claims 9
Claim · model-written summary
Sap pressure reached a maximum in 10 to 75 minutes in nutrient solution.
- Taxon
- tomato
Solanum lycopersicumt0 - Outcome
- pressuree0
- Direction
- increasede0
- Value
- 10 to 75 minutese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“pressure increased to a maximum within 10 to 75 minutes; maxima varied in the range of 20 kPa to 150 kPa”
t0“tomato plants”
Claim · model-written summary
Maximum sap pressure ranged from 20 to 150 kPa.
- Taxon
- tomatoSolanum lycopersicumt0
- Outcome
- maximae0
- Value
- 20 kPa to 150 kPae0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“maxima varied in the range of 20 kPa to 150 kPa”
t0“tomato plants”
Claim · model-written summary
Repeated pressure cycles reduced sap pressure maxima.
- Taxon
- tomatoSolanum lycopersicumt0
- Treatment
- pressure cycles were repeatede0
- Outcome
- pressure maximae0
- Direction
- decreasese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“decreases in pressure maxima over time as pressure cycles were repeated”
t0“tomato plants”
Claim · model-written summary
Stopping aeration decreased sap pressure after about 30 minutes.
- Taxon
- tomatoSolanum lycopersicumt0
- Treatment
- root zone aeration was stoppede0
- Outcome
- pressuree0
- Direction
- droppede0
- Value
- about 30 minutese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“When root zone aeration was stopped or a nitrogen atmosphere was used, pressure dropped following a lag of about 30 minutes.”
t0“tomato plants”
Claim · model-written summary
Nitrogen atmosphere decreased sap pressure after about 30 minutes.
- Taxon
- tomatoSolanum lycopersicumt0
- Treatment
- a nitrogen atmosphere was usede0
- Outcome
- pressuree0
- Direction
- droppede0
- Value
- about 30 minutese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“When root zone aeration was stopped or a nitrogen atmosphere was used, pressure dropped following a lag of about 30 minutes.”
t0“tomato plants”
Claim · model-written summary
Resupplying aeration partially reversed the pressure decrease.
- Taxon
- tomatoSolanum lycopersicumt0
- Treatment
- aeration was resuppliede0
- Outcome
- decrease in pressuree0
- Direction
- partially reversiblee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This decrease in pressure was partially reversible when aeration was resupplied.”
t0“tomato plants”
Claim · model-written summary
Imposing a root zone temperature gradient changed sap pressure nearly instantly.
- Taxon
- tomatoSolanum lycopersicumt0
- Treatment
- imposing a temperature v gradiente0
- Outcome
- sap pressuree0
- Qualifier
- Near instantaneouse0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Near instantaneous changes in sap pressure occurred when the root zone was manipulated by imposing a temperature v gradient or by increasing the osmotic potential of the solution.”
t0“tomato plants”
Claim · model-written summary
Increasing solution osmotic potential changed sap pressure nearly instantly.
- Taxon
- tomatoSolanum lycopersicumt0
- Treatment
- increasing the osmotic potential of the solutione0
- Outcome
- sap pressuree0
- Qualifier
- Near instantaneouse0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Near instantaneous changes in sap pressure occurred when the root zone was manipulated by imposing a temperature v gradient or by increasing the osmotic potential of the solution.”
t0“tomato plants”
Claim · model-written summary
The sap pressure monitoring technique may help assess effects of root environments and plant health.
- Taxon
- plantsViridiplantaee0
- Outcome
- determination of the role of changing root zone environments on sap fluxe0
Not reportedComparatorValue
Verbatim
e0“The technique reported may be useful for determination of the role of changing root zone environments on sap flux and perhaps for assessment of the health status of plants.”