To demonstrate hydrotropism in plants we can setup arrangements as follows:
i. Take a big vessel and plant a seedling in the vessel containing soil.
ii. Take a porous pot containing water adjacent to the seedling and fix it.
iii. Leave the set up for a few days.
Observation :After a few days it is observed that the roots bend towards the source of water (porous pot ) rather than growing straight.
Conclusion:As the roots grow towards the porous pot with water it is confirmed that the plant shows hydrotropism. We know that hydrotropism is a plant growth response in which the direction of growth is determined by a stimulus of gradient in water concentration.