Science Project

Yuwei's Science Project

The Effect of Light on the Germination of Bean Seeds

Problem

When seeds are planted, they are buried in the earth and receive little sunlight. So the question is: if seeds are planted in an environment where there is no light, will they germinate?

Hypothesis

According to my research, there are three basic elements for the germination of most seeds: air, temperature and moisture. Light is not mentioned for most seeds. So my hypothesis is that light will not affect seed germination.

Materials

Materials
amount	supply
12	bean seeds (long bean)
2	6-pack vegetable pots
1	cardboard box
some	garden soil
some	Miracle Grow
2	dark plastic containers
some	water
1	digital camera

Procedure

1. Choose 12 healthy bean seeds, about the same size. Then randomly seperate them into two groups, one for control, one for experimental.

2. Mix Miracle Grow Potting Mix with normal garden soil (the combinations make better soil, according to experience).

3. Put some mixed soil in the pots, then plant the seeds in the soil, about 1/2 inch deep. Water throughly. Then label the expiremental group and control group with two sheets of paper.

4. Place both pots into the plastic containers. Then cover the container for the experimental group with a lid to prevent light coming into the container. Since my testing showed that there may be some light passing through the plastic container, I put the container for experimental group into a cardboard box to achieve full darkness. Place both containers in a bright spot, without direct sunlight, so that they will have about the same temperature.

5. Each night, check water and record the number of bean seeds germinated. Take pictures when there are changes.

6. Exchange the two containers every night, because the air inside the covered container tends to be damper than the other.

Results

Number of Seeds Germinated
Day	Control	Experimental
1	0	0
2	0	0
3	0	0
4	0	1
5	3	1
6	2	1
7	0	0
8	0	0
Total	5 (83%)	3 (50%)

Experimental Control

Seeds started germinating on day 4 and ended on day 6.

Conclusions

1. Light affects seed germination

The results showed that a higher percentage of seeds geminated in the control group than in the experimental group, suggesting that, in contrary to my hypothesis, light affects the germination of bean seeds.

2. Only a small amount of light is needed to affect seed germination

My research showed that seeds with thin coats may need light to germinate. Bean seeds have thin coats. The higher percentage of seed germination in the control group suggests that, although bean seeds were planted deep in the earth, the small amount of light passing through the earth still had some effect on seed germination.

3. Bean seeds can germinate without light

Since half of the seeds in the experimental group germinated without light, this result suggests that light may not be absolutely necessary for bean seed germination.