Define the term diffusion pressure deficit (DPD) and also write its relation.
Diffusion pressure deficit (DPD) : It is the decrease in diffusion pressure of water in a solution over its pure state.

The diffusion pressure of pure water is maximum and it continues to decrease as more and more solute is added into it.

D.P.D = O.P - T.P
D.P.D. = Diffusion pressure deficit
O.P = Osmotic pressure
T.P = Turgor pressure