Ascent of xylem sap, caused due to transpiration, depends mainly on three physical properties of water. These properties result in

The transpiration driven ascent of xylem sap depends mainly on the following physical properties of water- cohesion ,adhesion and surface tension. These properties give water high tensile strength, i.e., an ability to resist a pulling force, and high capillarity, i.e., the ability to rise in thin tubes.