Figure 6.20: Potometer measures the rate of transpiration.Investigation: Determining the effect of environmental conditions on transpiration rate
using a potometer
Aim:
To determine the effect of environmental conditions on transpiration rate (using a simple
potometer).
Apparatus:
- a drinking straw
- a soft green leafy shoot
- Vaseline
- Marking pen
- Play dough / putti/prestix
- Plastic bag
- Elastic band
- Ruler
Method:
A potometer measures the rate of transpiration by measuring the movement of water into a
plant. The following experiment uses a simple hand made potometer.
Learners can be divided into four groups as each group will investigate a different factor and
then all the results can be shared at the end of the investigation.
Perform the following steps under water:
Chapter 6. Support and transport systems in plants 173