Measuring Transpiration (PRACTICAL)
A POTOMETER can be used to estimate transpiration rate
Measure Water uptake
1) Cut a plant shoot underwater
2) Put the potometer in the water
All air is trapped
3) Keep the capillary tube in the water
4) Dry the leaves, then shut the tap
5) Let 1 air bubble out and record the distance moved
Environmental Conditions affect the rate
Light Intensity
Use a lamp to increase rate
Put the potometer in a cupboard to decrease the rate
Temperature
(warm and cold room)
Increase in temp, increase in rate
Decrease in temp, decrease in rate
Humidity (spray water into a plastic bag)
Should decrease the rate
Wind Speed
Fan to increase wind speed
More wind speed, increase in rate