Question

explain the various factors affecting transpiration

Answer 1

The environmental factors affecting transpiration in plants include light, relative humidity, temperature, availability of water, and wind. Specifically, these are climatic elements which also affect photosynthesis and other plant growth and development processes.

Answer 2

$\large{\underline{\rm{\blue{Factors\: affecting\: transpiration:-}}}}$

→ External factors: Temperature, light, humidity, wind speed etc.

→ Plant factors:

o Number and distribution of stomata.

o Number of stomata open.

o Water status of the plant

o Canopy structure etc.

★ The transpiration driven ascent of xylem sap depends mainly on the following physical properties of water:-

→ Cohesion:- Mutual attraction between water molecules.

→ Adhesion:- Attraction of water molecules to polar surfaces

→ Surface Tension:- Water molecules are attracted to each other in the liquid phase more than to water in the gas phase.

→ These properties give water high tensile strength and high capillarity.

→ The xylem vessels from the root to the leaf vein supply the water for photosynthesis.

→ The concentration of water vapour in the atmosphere is lower as compared to the substomatal cavity and intercellular spaces. This also helps water to diffuse into the surrounding air. This creates a 'pull'.