Let us make in-depth study of the important advantages and disadvantages of transpiration in plant life.
Advantages of Transpiration:
Transpiration is regarded as a boon to the plants for many reasons:
1. It creates suction force and helps in the ascent of sap.
2. It affects the diffusion pressure deficit, thereby indirectly helping diffusion through the cells.
3. It affects the absorption of water and minerals by roots.
4. It helps in evaporating excess amount of water.
5. It plays an indispensable role in the translocation of food from one part of the plant to the other.
6. It maintains suitable temperature for the leaves and also renders cooling effect to the plant body.
7. It brings about opening and closing of stomata which indirectly influence the process of photosynthesis and respiration.
Disadvantages of Transpiration:
1. Transpiration often results in water deficit (capillary water) which causes injury to the plants by desiccation.
2. Rapid transpiration causes mid-day leaf water deficit (temporary wilting). If such condition continues for some time, permanent water deficit (permanent wilting) may develop, which may be fatal to the plants.
3. Many xerophytes have to develop structural modifications to reduce transpiration. These modifications are extra burden on the plants.
4. Excessive rate of transpiration leads to stunted growth of plants.
5. Since approximately 90 percent of absorbed water is lost through transpiration, the energy used in absorption and conduction of water goes waste.
Curtis (1926) has rightly called that “Transpiration is a necessary evil” because of its advantages and disadvantages.