Describe the mechanism of photoperiodic induction of following.

Explanation

Photoperiodic stimulus is perceived by the leaves. Floral hormone is synthesised in leaves and treanlocated to the apical tip to promote folowering. This can be explained by a simple experiment on Cocklebur (Xanthium pensylvanicum), a short day plant. Usually Xanthium will flower under short day conditions. If the plant is defoliated and kept under short day conditions it will not flower. Folowering will occur even when all the leaves are removed except one left. If a cocklebur plant is defoliated and kept under long day conditions, it will not folower. IF one of its leaves in exposed to short day condition and rest are in long day condition, flowering will occur.