Question

How root/shoot ratio affects transpiration?

Answer 1

Hint: Transpiration is the process of evaporation of water from the aerial parts of the plant. The loss of water is through the stomata present in the leaves. Transpirational pull is responsible for uptake of water by the root.

Complete Answer:
- Transpiration is the loss of water in the form of vapour from the aerial parts of the plants like stem leaves. It depends on many factors which are both internal and external.
- The external factors include temperature, sunlight, atmospheric pressure, humidity etc. Internal factors like leaf area, leaf structure, root/shoot ratio etc affect the rate of transpiration.
- The roots absorb the water from the oil. The water is conducted to all the parts of the plants by the vascular bundles. Transpiration occurs through the shoot. If the roots surface area is greater, then plants will be able to absorb more water.
- As a result of which more water will be available for transpiration by the shoot. This is only possible if root area equals the shoot area. According to Parker, High root/shoot ratio increases the rate of transpiration whereas low root/shoot ratio decreases the rate of transpiration.

Additional Information- Root pruning is done in order to reduce the rate of transpiration. Some water is also lost by the plant by the process of guttation in which the water lost is in the form of droplets.

Note: The water moves from the Xylem into the mesophyll cells of the leaves. It evaporates from the leaf surface through the stomata by the process of diffusion.