Question

Guttation take place during night when :

• A. Root pressure is negative
• B. It does not takes place at all
• C. Always take place
• D. Root pressure is positive

Answer 1

The correct option is D Root pressure is positive

Guttation is the loss of water in liquid form as a dilute solution from uninjured leaf tips. The uninjured leaf tips have hydathodes or water stomata.

Under conditions of low transpiration dilute solution of minerals oozes out through them under the influence of increased root pressure. Thus, mostly guttation is observed during night time when transpiration is low, for example, due to high atmospheric humidity and sufficient water is present in soil. The most important force responsible for guttation is positive root pressure.

Hence, option A is correct.