From the root pressure experiment, it may be conclude that water molecules move through xylem due to root pressure and not transpiration. The process of osmosis and diffusion helps water to pass from soil to root hair tips and finally to the xylem. Root pressure then joins the water lines inside the xylem and prevent the formation of air bubbles. This also helps in moving the water up. Root pressure is tranverse osmotic in nature and causes guttation at night.
