Different types of lights have been used to increase the growth of various plants. Our experiment tested whether LED or fluorescent lights produce plants with longer root length and higher germination rates. Fluorescent lights, which emit heat, consume

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Effects of LED and Fluorescent Lights on Root
Growth of Arabidopsis Kevin OQuinn, Mesha
Arant, Jordan Ball, and T.J. WhiteDepartment of
Biology, Wofford College, Spartanburg, SC 29303
The germination rate, not shown, was not
statistically different for seeds under
fluorescent and LED light (Chi-square
(dF1)0.137 p.712).
Different types of lights have been used to
increase the growth of various plants. Our
experiment tested whether LED or fluorescent
lights produce plants with longer root length and
higher germination rates. Fluorescent lights,
which emit heat, consume more energy, and emit a
more intense light are typically used in
laboratories. LED lights, which consume 10 less
energy than fluorescent lights, can last for many
more years that fluorescent lights, but are more
expensive. Are the LED lights really worth the
cost? We performed an root growth experiment to
find out.
1. Germination was not affected by light source.
2. Root growth was greater under fluorescent
lights. Our results did not support our
hypotheses.
Our experiment showed that fluorescent lights
produced plants with longer roots than the LED
light panel. Of course, one of the drawbacks of
fluorescent lights is that it requires more
energy than LED lights to operate. This may be
contribute to higher operational costs, but may
have aided in the difference in root lengths
between the fluorescent and LED lights. Because
the fluorescent lights used more energy, perhaps
that they emitted more energy. This extra energy
could have given the plants grown under
fluorescent lights the advantage. In comparison,
because the LED lights used less energy, they
emit less energy this could have contributed to
the shorter root length. Since the LED lights
were less intense, we should have moved them
closer to the plants in order to have the same
intensity as the fluorescent lights. In the
future, it would be best to figure out the
distance from the lights to the plants in order
to equalize the intensity being exposed to the
plants.  

1. Germination rates will be higher in plants grown
   under the LED lights.
2. Root length will be greater in plants grown
   under the LED lights.

• Materials
• 48 Arabidopsis seeds(Ecotype Columbia)
• Petri dishes with 0.8 Agar
• Fluorescent and LED Growing Lights
• Methods
• 0.8 Agar was placed into 6 slanted Petri dishes.
• Eight seeds were placed in each dish along the
  thin edge of the agar to reduce crowding.
• Dishes were sealed and placed in a vertical
  position under the LED and Fluorescent lights at
  a distance of 34cm. On a photoperiod of 16 hours
  light and 8 hours dark.
• Each seed was individually identified.
• Germination rates and root length were measured
  weekly for two weeks.
• Dishes were placed on a scanner and the images
  were analyzed with ImageJ software root lengths
  were measured.

The circles show the average root length and the
error bars show 95 confidence intervals. Root
growth from week 1 to week 2 was greater for
plants grown under Fluorescent lights than for
plants under LED lights (p0.002, Chi Square
Fdf1,361.8. ) We did not graph the growth from
Week 0 to Week 1 because during that interval
growoth was likely produced by energy from the
seeds endosperm and not from the light.
We thank G.R.. Davis for assistance with
experimental design , Ab Abercrombie for help
with statistical analysis, and A. Steadman and
T. Player for helpful comments.