The transpiration pull is just one of the mechanisms that explain the movement or translocation of water in plants, particularly water ascent in tall trees. There is no single exacting explanation as yet for the ascent of water but several theories have been proposed. Of these, the one which has gained wide support is the cohesion-tension theory which recognizes the crucial role of transpiration pull as a driving force. These theories are briefly described below.. I dont know maybe this might be helpful
