Question

When air humidity is high does the plant transpiration increase or lower?

Answer 1

When air humidity is high, plant transpiration decreases.

Explanation:

Water from the roots to leaves is primarily driven by water potential difference. When the water potential is lower outside the leaf than near the stomatal air space, then water evaporates from the stomata to the atmosphere.

Drier surroundings and decreased relative humidity outside the leaf, increases the rate of transpiration.

Humidity , temperature , wind , incident sunlight and size of stomatal opening all influence the rate of transpiration.