The main difference between transpiration and guttation lies in their definition. When water is lost from the aerial parts of the plants, in the form of vapours, it is defined as transpiration. On the other hand, when water is lost in the form of liquid from the uninjured margins of leaves is called guttation. So in transpiration the water is lost in the form of vapour and in guttation the water is lost in the form of liquid.
Plants tend to absorb water from the soil and and there are ways in which plants get rid of excessive water. Transpiration is one of those ways in which water is lost from the living tissues of the aerial parts of the plant in the form of vapours. It provides cooling effect to the plant and generally occurs in the daytime. There are three types of transpiration are Stomatal transpiration, Lenticular transpiration, and Curticular transpiration. As the name indicates, stomatal transpiration occurs through stomata and is the most common type of transpiration. Curticular transpiration takes place through the cuticle of the leaves. Lenticular transpiration occur through lenticles of the leaves, which are loosely arranged mass of cells in the bar of stem. It helps to keep the temperature of the plant low and the main factors affecting transpiration are humidity, light, temperature, water, soil and man more.
Loss of water in the form of liquid from the aerial parts of the plant is called guttation. This process can usually be witnessed in plants in early morning and at night, mostly in herbaceous plants growing in high humidity conditions and high moisture of soil. The main trigger for guttation to take place is when the rate of transpiration in plants become low and root pressure becomes high. This is when guttation comes into play and the water is forced out in the form of drops through hydathodes which are special pores in the leaves.
- Transpiration is loss of water in the form of vapour and guttation is loss of water in the form of liquid.
- Transpiration occurs through stomata, lenticles and cuticles. Guttation occurs through hydathodes.
- Transpiration occurs mostly during day time and guttation occurs mostly during the cold hours of night.
- The transpired water is pure, while guttated water is a dilute solution of both organic and inorganic substances.
- Excessive transpiration causes wilting. But excessive guttation does not cause wilting.
- Transpiration continues even when the plant is under stress but guttation does not.