Can different color stained glass affect plant growth? By the Narwhals

Background Research Other experiments have found that different colors do affect plant growth. One experiment by Adam Z. Kalawi found that plants under a blue light died off after a while, and other darker colors grew taller. Why did they grow taller? For more info, check out: http://www.usc.edu/CSSF/History/2005/Projects/J1625.pdf

So we set up our own experiment…

Hypothesis The plants will grow faster in lighter colors because more sunlight can pass through the lighter colors. It will take longer for plants to grow in darker colors because not as much light can pass through.

Materials 6 pots of moist soil Radish seeds Blue, yellow, and clear plastic wrap Wooden stakes Tape Water Graduated Cylinder Ruler Growth light.

Procedures Each pot gets a pinch of radish seeds. 2 are placed under the clear plastic wrap, 2 are placed under the yellow, and the last 2 are placed under the blue. The plastic wrap is held up by the wooden stakes. Everyday, each team member should count how many sprouts have germinated and take the height of the tallest sprout in cm. They should also water their plants with 25 ml of water.

Alec- clear Becky-Yellow Alli-Blue

This went on for 12 days...

This photo was taken about midway through the experiment…

Here are our results Day 1 Day 4 Day 5 Day 6 Day 7 Day 8 Day 11 Day 12   Day 1 Day 4 Day 5 Day 6 Day 7 Day 8 Day 11 Day 12 Control 1 0 Sprouts 0 cm 34 S >1 cm 38 S 41 S 5 cm 6 cm 46 S 7.5 cm 47 S 8 cm 52 S 8.5 cm Control 2 31 S 39 S 4.5 cm 40 40 S 6.5 6.3 cm Yellow 1 0 sprouts 44 S 3.5 cm 50 S 51 S 5.5 cm 55 S 67 S Yellow 2 20 S 27 S 29 S 37 S 7 cm Blue 1 19 S 30 S 33 S 6cm 35 S 49 S Blue 2 13 S 23 s 24 S 6.5 cm 8.5 9 cm

These were the plants under the clear wrap at the end of the experiment

These were the plants under the yellow wrap at the end of the experiment

These were the plants under the blue wrap at the end of the experiment.

Conclusion We reject our hypothesis because it was not correct. Instead of the plants taking longer to grow, the colors effected the way that they were growing. Different colors do affect plant growth. The plants under the blue light were very tall because they didn't receive enough light. There was less sprouting in the blue than either the clear or yellow. The plants under the yellow light were tall, but not as tall as the blue because they received more light. The control plants were healthy and short because they received enough of the light to not stretch. When choosing colors in stain glass, pick lighter colors because plants will grow healthier and the seeds will sprout faster. This is because the plants under the lighter color will receive more sunlight than it would under a dark color.

Sources of Error We could have made the experiment better by giving the plants more water than 25 ml and put the exact same number of seeds in each pot.