Explain how the various environmental factors affect the rate of transpiration in plants (20mks)

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Temperature
  • The higher temperature the faster the rate of transpiration; increase in temperature increases the capacity of atmosphere to hold water and moisture; increased heat increase  internal temperature  of the leaf  hence water evaporation;    [4 accept converse]
 Atmospheric pressure
  • Lower atmospheric pressure, higher rate of transpiration   
Humidity;her rate of transpiration; low humidity increases the saturation defiant; hence water moves from leaves to drier atmosphere;                       4
Wind;
  • When it is windy the rate of transpiration is higher; wind sweeps away vapour that has accumulated at the surface of leaf; increasing saturation deficit; hence faster rate of transpiration.
Light intensity;
  • Higher light intensity; faster rate of transpiration high light intensity increase photosynthesis rate hence stomata opens;                             
Amount of water in soil;
  • More water in the soil increases the rate of transpiration; it wets the xylem (ensure xylem is wet throughout);     


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