Question

The spray of PMA causes

• A. Decrease in transpiration
• B. Increase in transpiration
• C. Increase in absorption
• D. Increase in guttation

Answer 1

The correct option is A Decrease in transpiration

Transpiration is loss of water in vapour form through stomata. Rate of transpiration depends on vapour pressure gradient between the internal environment of leaf and atmosphere.

More the atmospheric humidity lesser the transpiration.

Phenyl mercuric acetate (PMA) is a general anti-transpirant, which decreases the rate of transpiration by bringing about a closure of guard cells.