Plants and Lights

Abstract-

I wanted to find out which colored light bulb will grow plants the biggest. I chose this for my topic because my brother did a college experiment where they measured lazers and beams to find out which would melt through items the fastest. Since I was unable to do that experiment because my mom doesn’t trust me. I found that growing could be just as interesting as melting. I predict that the regular light bulb will grow the plants the biggest because the regular light bulb is the brightest out of them.

For my project I placed two different types of plants under each light bulb. Under the light bulbs there was a rosemary plant and a mint plant. All of the plants were cut down and measured to the same height. All plants were watered with the same amount of water (½ cup) on a consistent basis. After each week plants were measured by inches and jotted down on a graph.

Over the duration of this project it didn’t take long to find a difference from the starting measurement. Each of the plants started to grow almost instantly. After the course of four weeks I found some pretty interesting results. The plants that grew the biggest happened to be the plants under the orange light. The mint plant grew 14 inches, and the rosemary plant grew 6 inches. The second best plants were the plants underneath the regular light bulb. The mint plant grew 11 inches and the rosemary grew 5 inches. The third light that had the highest growing was the yellow light. The mint plant grew 9.5 inches, and the rosemary 4.5 inches. The blue light came in fourth. The mint plant grew 9 inches, while the rosemary grew 4 inches. The purple lights plants grew the least. The mint plant grew 8 inches, and the rosemary only grew 3 inches. Some things that I have noticed over this project were quite interesting. The darker colored lights like the blue and purple would grow droopy and like out to the side. The lighter colored lamps would grow straight and tall until they reached about 18 inches than they started to droop at the top.

At the end of my experiment, I found that the orange light had the best growth with a growth of 14 and 6 inches for the plants. My hypothesis was surprisingly incorrect. I would of bet that the regular bulb would grow the most knowing that it is the brightest and that it does represent the sun the best. I thought my experiment was very fair knowing that all the watages were the same and each plant was watered equally. One way I could improve my experiment is by letting them grow for a longer span of time and maybe get more colored lights.

Conclusion-After conducting my project I have to say I am very surprised my hypothesis was incorrect. At the start of my project I predicted that the regular/white light would grow to be the biggest. However at the end of my project I have found that the orange light grew the plants the biggest with it’s mint plant growing 14 inches and the rosemary growing 6 inches.

I feel that this was a very fair project. Each plant started at the same growth point. Each plant had the same wattage bulb, was the same distance from the light and was watered the same each day. If I were to do this project again, I think I would add more colored bulbs to see if they had a better effect on growth.

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Data table-

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