1. The Effect Of Food Coloring on Plant Growth Daniel Schapira February 2, 2008 Central Catholic High School

2. Introduction  Plants are exposed to many harmful chemicals during their growth. Some of these chemicals help the growth of these plants. If food dye could significantly affect the growth of plants, it could replace many of those harmful chemicals.  Food coloring has many chemicals in it that could affect the plant. It has glycerine, FD&C blue 1, Citric Acid, and Sodium Benzoate.

3. Glycerine  Has the chemical compound HOCH 2 CH(OH)CH 2 OH. It is a colorless, odorless, viscous liquid. It is used in pharmaceutical formulas, a humectant, and may help to preserve foods.

4. FD&C Blue 1  Gives the food coloring its dark blue color.

5. Citric Acid  A weak organic acid found in citrus fruits. It is also a natural preservative, and an important component of the citric acid cycle. It occurs in the metabolism of almost all living things. It is also an environmentally benign cleaning agent and an antioxidant.

6. Sodium Benzoate  Also called E211, has the chemical formula C 6 H 5 COONa. It is a sodium salt of benzoic acid and exists in this form when dissolved in water. It can be produced by reacting sodium hydroxide with benzoic acid. Also used as a preservative. It is bacteriostatic (it hampers the growth of bacteria by interfering with bacterial protein production, DNA replication, and cellular metabolism). Also fungistatic (stops fungi from reproducing). Only effective in acidic conditions (pH<3.6). Concentration as a preservative is limited by the FDA in the U.S. to.1%.

7. Hailstone White Radishes  These were the radishes used.  They grow quickly and are suitable to be grown in either spring or fall. They are usually ready to harvest around 26 days. They require loose fertile soil, and for the soil to be uniformly moist.  They grow best in colder weather. At about 45 degrees Fahrenheit.

8. Similar Experiments  A similar experiment was conducted using beans instead of radishes. This other experiment found that food coloring didn’t affect the growth of the plant. However, they did find that enough coloring would tint the plant a different color.

9. Null Hypothesis  The variable (food coloring) will not significantly affect the growth of the radish plants.

10. Hypothesis  The 10mL/L concentration of food dye will affect the plants’ growth the most.  The 1mL/L concentration of food dye will affect the plants’ growth slightly less than the 10mL/L concentration.  The control will affect the plants’ growth the least.

11. Materials & Materials Methods  Planted thirty-six seeds in total. Created two different concentrations of food dye in water (10mL/L) and (1mL/L).  Then charted the growth in height every two days. Materials  Butler’s Blue Food Color  74 Hailstone White Radish seeds  3 Grow Lights mounted on a rack  6 flats  3 Trays (2 flats per tray)  1 Liter beaker  Spring Water  Rack (3 shelves)(1 tray per shelf)  1 Cup beaker  2 Metal Trays  1 Drying Oven

12. Procedure  Made 2 stock solutions 10mL food dye/1L of water, and 1mL food dye/1L of water.  Placed 2 flats in each of 3 trays, and 1 tray on each shelf on the rack.  Planted 12 Hailstone white radish seeds per flat.  Watered top shelf with 10mL/L solution.  Watered middle shelf with 1mL/L solution.  Watered bottom shelf with (control) with water.  Left grow lights on 24/7.  Watered plants (1cup each) every 2 days.  Measured plant height every 2 days.  Dried and massed each plant at the end of the experiment.

13. Purpose  The purpose of this experiment was to find the influence that food coloring has on plant growth.  The reason for picking this experiment was that previous experiments have shown that food dye effects color of the plant, but these experiments say nothing of how it effects the growth.

14. Food Coloring Affect On Plant Growth

15. Conclusion  The null hypothesis, that the food coloring will not significantly affect the growth of the radish plants was accepted (p-value=0.87164).