Experiment to demonstrate Hydrotropism:
Take a glass trough and fill it with sand. Keep a Pea seedling at the centre. A porous pot with water is kept at the Trough, as shown in the diagram. Keep it for six or seven days. The Radicle has grown towards the porous pot and moisture, instead of growing vertically downward. It proves that primary root is positively Hydrotrophic and that hydrotropism is stronger than Geotropism.