Briefly describe water potential. What are the factors affecting it?

Explanation

"The measure of the relative tendency of water to move from one area to another is called water potential". It is denoted by the Greek symbol Psi or `Psi` and is expressed in pascals (Pa). It has two components namely solute potential and pressure potential.
a) Solute potential: If some solute is added to pure water, the solution has fewer free water molecules and the concentration of water decreases reducing its water potential. The magnitude of this lowering due to dissolution of a solute is called solute potential. It is denoted as `Psi_(s)`. It is always negative.
b) Pressure potential : When water enters a plant cell due to diffusion, causing a pressure to build up against the cell wall. This makes the cell turgid. The magnitude of increase in water potential in such turgid cell is called pressure potential. It is usually positive and is denoted as `Psi_(P)`.
`Psi = Psi_(S) + Psi_(P)`