The Effect of Artificial Light on Red Clover

The Effect of Artificial Light on Red Clover Seed Growth The Rare Pears Isabella, April, Nikki

Our Research Question • Which source of artificial light promotes Red Clover seed growth best in comparison to sunlight?

Hypothesis • Our hypothesis is that the fluorescent light bulb will be the best alternative to sunlight. • We predict this because fluorescent light bulbs offer the longest variety of visible wavelengths, which plants obtain normally from the sun.

Equipment and Materials • Halogen bulb (60 watt) • Fluorescent bulb ( 60 watt) • Soft white bulb (60 watt) • Three empty cabinets • • • Four cups Ruler Distilled water Soil 3 desk lamps 20 red clover seeds

Procedure • We first let our red clover seeds soak in water overnight. • The next morning, some of the radicles had emerged!

Procedure • We labeled our four cups sunlight, fluorescent, halogen, and soft white. • We planted five seeds into each cup about half-way down into the soil. • We then set up our three lamps in three different cabinets so that each group of sprouts would only get that one kind of artificial light.

Procedure • The sunlight seeds were our constant, so we put them on a windowsill to grow. • Each lamp was placed 24 cm away from the top of the cups. • The lamps were turned on at 8 am and were turned off at 4 pm for a period of two weeks.

Measurements • During class time, one of us would come in and measure the plants while one of us would record. • The first plants to spring up were the plants under the soft white bulb, the halogen bulb, and the fluorescent bulb.

Soft-White’s Effect • From the graph you can see that there was steady growth up to the 14 th day. • However, by the 14 th day, the red clover plants were shriveled and dieing. • We believe this to be because the soft-white bulb was giving off more heat than the other two light bulbs.

Final Results: Soft-White

Halogen’s Effect • The red clover under the halogen bulb also had steady growth. • The red clover seeds under the halogen bulb grew fast. • By the 14 th day, the red clover plants were also shriveled and mostly all of the sprouts were dead.

Final Results: Halogen

Fluorescent’s Effect • The red clover under the fluorescent bulb also had steady growth • By the 14 th day, the sprouts seemed to be healthy enough to stand, and their blades were fuller and greener in comparison to the soft-white and the halogen red clover.

Final Results: Fluorescent

Sunlight’s Effect • The red clover under sunlight had steady growth, but they did not grow as fast as the red clover under artificial light • By the 14 th day, however, the plants were much healthier in comparison to the red clover under the three artificial lights.

Final Results: Sunlight

Experimental Errors • Around day 9, the sunlight pot fell off the third floor at the dorms. The plants were rescued, but this caused measurement errors. • The halogen plants when watered on day 10 were accidentally flooded, and we believe that one of the halogen sprouts died because of this.

Conclusion • Out of the three sources of artificial light, the fluorescent bulb gave the closest results to the constant, sunlight. • The red clover under the artificial lights experienced more growth to their apical meristems causing them to grow tall, but the lack of growth in the lateral meristems caused the plants to become unable to support themselves. • The red clover under the sunlight had steady growth in the apical and lateral meristems.

Questions?