The role played by growth in the determination of water deficit in plants

The aim of this work was to establish under what conditions the water deficit values obtained byStocker’s (1929) method can be considered to be those for actual water deficits. It was found that the water intake of detached leaves is not necessarily due only to incomplete saturation of the leaf tissues with water, but that in young leaves it is caused to a great extent by their extension growth. Thus, water deficit in the sense ofStocker’s definition is not merely a simple physiological state of incomplete saturation of the tissues, but is expressed by the sum of the need for water to achieve the greatest possible saturation of the tissues and the need for water in the normal course of the extension growth of cells.