Describe an experiment to show hydrotropism.

Fill three fourths of a glass aquarium with dry sand. Sink a porous pot into the sand. Plant a pea seedling somewhat away from this pot. Then fill the pot with water. The water from this pot will seep through its sides and keep the surrounding sand moist. After about one or two weeks, observe the roots of the seedling either through the glass dish or by carefully uprooting the plant.

You will find that the roots turn towards the direction of the water.