Growing with the lights By:

Question: How do different types of artificial light affect the growth of plants compared to sunlight? I asked that question, and I was determined to find the answer. What if there was a another way to grow plants, faster than sunlight? I tested with LED, Fluorescent, and Incandescent lights.

Hypothesis: If I leave each plant under the same conditions, then the LED light will make the plants grow the fastest. First, like any other experiment, I had to form a hypothesis.

Alternate Hypothesis: If I leave each plant under the same conditions, then all of the plants will grow the same length. I decided to make another hypothesis. I researched this, and Wikipedia called it an Alternate Hypothesis.

Control Since I was doing an experiment that tested against sunlight, I had to use sunlight as the control. A control makes sure that my experiment is good, and something changed. If the data is the same on the control and the items I tested, it’s a fail.

Materials For this experiment I had to use: Three lights (LED, fluorescent, Incandescent), a plastic container (Windowsill greenhouse), seeds (micro greens rainbow blend), absorbent soil, light bulbs, a timed power adapter, and water.

Constants Here are my constants: Container, soil, water, temperature, distance between lamp and seeds, same closed space, duration of light, and plants. Constants are whatever stays the same. So if I watered my plants 30 milliliters of water a day, I would have to keep it the same, or else it would not be constant.

Dependent Variable and Independent Variable My independent variable was the kind of light hitting my plants. The independent variable is the “if” part of the hypothesis. My dependent variable is how much the plants grew. The dependent variable is the “then” part of the hypothesis.

Procedures First, I planted 60 seeds in each of the four auto- water containers on 4/13/14. I set my light to turn on when the sun comes up and off when the sun went down. Finally, on 4/21/14, I recorded the data of how much the plants grew.

Planting_1 (Before)

Getting the water

Planting_2 (After)

Lights

Timer It’s programed to turn on at sunrise and turn off at sunset

Mistakes One mistake that I made was that I thought that the fluorescent light was the LED light, and I figured out at the end that it was switched. I learned from my mistake to look more carefully at what I’m doing in an experiment.

Results The average growth with incandescent light was 7.6 centimeters. With the fluorescent, it was 9.3 centimeters. The LED grew 6.8 centimeters, and sunlight’s average was 4.5 centimeters.

Results - Pictures Incandescent Light Fluorescent Light LED Light Sunlight

Chart For All Data Back Front

Chart For Average Data

Conclusion The fluorescent light made the plants grow the fastest, which was not like I predicted. Incandescent light worked the second best, but very surprisingly, the sunlight came in fourth. I figured out that the sun is very unpredictable and in order to know how much light your plants are getting, you have to use a lamp.