Transpiration is evaporation of water through stomatal openings in leaves. Factors affecting rate of transpiration are temperature, humidity, air movement and light intensity.
Effect of temperature on rate of transpiration
The higher the temperature, the higher the rate of transpiration. The hotter it is, the more water molecules evaporate.
Effect of humidity on rate of transpiration
The higher the humidity, the lower the rate of transpiration. The more saturated the air, the less evaporation can take place.
Effect of wind speed on rate of transpiration
The higher the wind speed the higher the rate of transpiration. The more water molecules are blown away, the more evaporation can take place.
Effect of light intensity on rate of transpiration
The higher the light intensity, the higher the rate of evaporation. The more stomata open during photosynthesis, the more water molecules evaporate.