Tag: long distance transport of water

Antitranspirants are substances that are applied to the leaves to reduce transpiration. They are used on trees, cut flowers and shrubs. They reduces transpiration in fruit plants like apples, pears, orange, crop plants like cotton, tea, roses, tuber crops like potato, carrot and vegetable plants like chillies, tomato, cabbage. These are also used to protect plants from drying out too quickly. Various antitranspirants include abscisic acid (ABA), aspirin, silicon emulsions, plastics, waxes.

Transpiration is the process by which moisture is carried through plants from roots to small pores on the underside of leaves, where it changes to vapor and is released to the atmosphere. Transpiration is essentially evaporation of water from plant leaves. Transpiration also cools plants, changes osmotic pressure of cells and enables mass flow of mineral nutrients and water from roots to shoots.

According to the transpiration pull theory, loss of water from aerial parts due to transpiration is a physical process and the loss of water generates the pulling force. Water is present as a continuous column in vascular tissues due to cohesive and adhesive forces. The loss of water due to transpiration is equal to the amount of water absorbed from the soil. More the transpiration loss of water, more the absorption of water from the soil and vice versa.

Transpiration generates tension in plants. This tension is the main pulling force, which pulls water to great heights in vascular plants. Thus, transpiration leads to the ascent of sap. Without transpiration, water and minerals will not rise from roots to aerial parts of plants and trees. 

Hydrophytes are plants growing in water. They may be submerged or floating. Floating hydrophytes have stomata on floating parts, for example, floating leaves of lotus have stomata on the upper surface. 

Transpiration is a loss of water in vapour form stomata. The rate of transpiration depends on a number of factors, like carbon dioxide concentration, temperature, light, humidity etc. The most important factor which governs the rate of transpiration is the vapour pressure gradient, which exists between leaf mesophyll and atmosphere. It has been estimated that almost 99 percent of water absorbed by plants is lost in transpiration. As transpiration generates the tension, which is the most important force responsible for water absorption.

Plants produce carbon dioxide and water as respiratory waste products. Plants get rid of excess water by transpiration and guttation. Transpiration is evaporation of water from plant leaves by stomata.

Transpiration is the process by which moisture is carried through plants from roots to small pores on the underside of leaves, where it changes to vapor and is released to the atmosphere. Transpiration is essentially evaporation of water from plant leaves.