the sciencey bit

An Investigation into the Effect of Light Exposure on the Growth and Development of Broad Bean Seeds in a Controlled Environment

Introduction

The broad bean is a legume native to North Africa and Southwest Asia, now extensively cultivated all over the world. Broad beans have a long tradition of cultivation in Old World agriculture (the agricultural science predominantly of Europe, Asia and Africa, dating back prior to the discovery of the Americas) and one of the reasons for this is the ease with which it can be grown (Saeed, 1968).

It is well established that plants need certain things in order to be able to grow. The most crucial of these are water and light, along with other contributory elements such as mineral nutrients and warmth, and in this respect broad bean seeds are no different from any other.

We wanted to look at the effect of sunlight in particular on the growth of broad bean seeds. Plants need sunlight (or the right kind of electric light), because without it they would not be able to complete the process of photosynthesis. During photosynthesis the plants use the sunlight to evaporate the water so that they can separate sugars and other important vitamins and nutrients to survive.

We planned to plant three broad bean seeds in controlled conditions, only each receiving differing amounts of sunlight, to see to what extent light exposure influences the rate of growth. One seed would receive full day-light exposure, another partial exposure and the final seed would be completely deprived of light.

We hypothesize that the seed with the greatest exposure to light will grow the most, followed by the seed receiving partial exposure to light, which we expect to grow fairly well too given the broad beans documented propensity for growth (Saeed, 1968), but just to a lesser degree. Further, we surmise that after an initial short period of growth, as a result of it feeding of the energy contained within the seed itself, the seed deprived of all light will stop growing and eventually wilt, wither away and die.

References

Saeed, E. A. K. El. (1968). Agronomic Aspects of Broad Beans (Vicia Faba L.) Grown in the Sudan. Experimental Agriculture, Volume 4, Issue 02, pp 151-159

Bibliography

Peacock, G., Sharp, J., Johnsey, R., and Wright, D. (2007) Primary science: knowledge and understanding. 3^rd edition.  Exeter: Learning Matters for general science conceptual development.

Farrow, S. (1999) The really useful science book: a framework of knowledge for primary teachers. London, Falmer.