Light intensity- The brighter the light, the greater the transpiration rate. Stomata begin to close as is it gets dark as photosynthesis cannot take place.
Temperature - The warmer it is, the faster transpiration happens. When it's warmer there is more energy to evaporate or diffuse.
Air Flow - The better the air flow (e.g. wind), the better the transpiration rate. If it is poor then water vapour just surrounds the leaf and doesn't move away; this means that there is a high concentration of water particles outside the leaf as well as inside it. If airflow is good it means that diffusion happens quickly from an area of high concentration to an area of low concentration.
Potometer can estimate transpiration rate by measuring the water uptake of a plant.
Drafted by Catrina (Biology)