Explanation

Ascent of Sap in plants was demonstrated by Girdling experiement. In this experiment, the cortex and phloem of a plant are removed. Due to which, conduction of food towards the cortex is stopped and conduction of water towards the stem by xylem remain unaffected i.e., ascent of sap occurs. For sometime, plant may survive, but after a period it dies due to the absence of sugar in root cells.