Question

Leaf fall occurs in a tree when there is an increase in concentration

Answer 1

growth Inhibiting hormone

Answer 2

Leaf fall occurs in a tree when there is an increase in the concentration of Abscisic Acid. The acid is a plant hormone that helps in the abscission of flowers and leaves in the plant.

Due to the reduction in photosynthesis, the abscission of leaves is triggered and then the layer started to product abscission when auxin content falls down resulting in the fall of parts of the plant.