Present cohesion-tension-transpiration pull model of water transport.

Explanation

In xylem the flow of water upward through in plants by transpiration is mainly dependent on following physical characteristics.
Cohesion Force : mutual attraction between water molecules.
Adhesion Force : attraction of water molecules to polar surfaces (such as the surface of tracheary elements).
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, as ability to resist a pulling force and high capillarity.
The ability to rise in thin tubes. In plants capillarity is aided by the small diameter of the tracheary elements the tracheids and vessel elements.