Which of the following contributes most to transport of water from the ground to the leaves of a tall tree?
Cohesion of water
Transpiration pull
Cohesion of water and transpiration pull contributes most to transport of water from the ground to the leaves of a tall tree. The property of water molecules getting attracted to other water molecules which is known as cohesion and the suction force produced by the upward pull of water helps to transport water to the leaves from the ground.
The two other forces, i.e. root pressure and a capillary rise of water in xylem are the comparatively minor forces.