Effect of moisture on direction of root growth
The hypothesis that the roots of the germinated green bean will grow towards moisture if the soil is dry is disproved.
The growth of a plant can be induced by geotropism, phototropism, hydrotropism or chemotropism. Geotropism is how the growth of a plant is affected by gravitational pull. As the stem grows away from the gravity, the roots will grow towards the pull of gravity. Phototropism is how a plant will bend and grow towards a light source. Hydrotropism and chemotropism is the study of how roots will bend towards moisture or a chemical source in the soil.
Try to repeat this science fair project by using different types of seeds like corn seeds or soy beans. Would your results be different?
The experiment can be conducted over a longer period of time to observe if the direction of root growth will change as the soil becomes drier.
Hydrotropism - http://www.plant-and-flower-guide.com/hydrotropism.html
Induced or paratonic movements - http://www.tutorvista.com/content/biology/biology-iv/plant-growth-movements/paratonic-movements.php
Hydrotropism - http://en.wikipedia.org/wiki/Hydrotropism
Basic safety requirements