Q. Transpiration increases in ______:
Answer: Hot, dry and windy condition
Notes: Conditions which increase the rate of evaporation also increase the rate of transpiration. Transpiration is more rapid in hot, dry and windy conditions than it is in still or humid conditions. Plenty of light also speeds up transpiration. Factors that affect transpiration rate Factor Description Explanation Light In bright light transpiration increases The stomata (openings in the leaf) open wider to allow more carbon dioxide into the leaf for photosynthesis. Temperature Transpiration is faster in higher temperatures Evaporation and diffusion are faster at higher temperatures Wind Transpiration is faster in windy conditions Water vapour is removed quickly by air movement, speeding up diffusion of more water vapour out of the leaf Humidity Transpiration is slower in humid conditions Diffusion of water vapour out of the leaf slows down if the leaf is already surrounded by moist air.