The process in which excess water absorbed by plant roots is released by evaporation through aerial organs is called transpiration or transpiration. Only 1-2% of the water absorbed by plant roots is used for biological purposes and 98-99% is lost through evaporation. Leaves are the main sensory organs of plants. According to the scientist Curtis, perception is a necessary evil. Perspiration rate is determined by Ganong Potometer. The report is divided into three parts.