Factors that affect transpiration
Environmental factors
six factors that affect transpiration (06 marks)
- Temperature: the higher the temperature, the higher the rate of transpiration due to availability of vaporization energy.
- Humidity: high humidity lows the rate of evaporation. Increase in the rate of humidity reduce water potential gradient between the leaf and environment reducing the rate of evaporation.
- Air movement/wind: blows away saturated air around the stomata facilitating evaporation. Strong wind lower the rate of transpiration due to closure of the stomata.
- Atmospheric pressure: the lower the atmospheric pressure, the greater the rate of evaporation.
- Light increases transpiration by opening the stomata and increasing temperature.
- Availability of water: Transpiration is high when there is continuous water supply in the soil to replace the lost water.
Internal factors that
- Surface area of the leaf. The bigger the leaf surface area, the higher the rate of transpiration.
- Thickness of the leaf cuticle; thin cuticle leads high rate if transpiration due to reduced diffusion gradient
- Stomata sizes and density: numerous big stomata allow fast rate of water loss.
- Distribution of the stomata: leaves with a big number of stomata on the upper cuticle loss water faster than those with the stomata on the lower cuticle.
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CATEGORIES General
TAGS Dr. Bbosa Science