1. Keara Miley – Lake Shore Robin Smith – Lake Shore
The Effects of pH and Temperature on the Germination of Raphanus sativus Seeds
Keara Miley – Lake Shore
Robin Smith – Lake Shore

2. Terminology Two-Factor Design of Experiment Raphanus sativus
(DOE)
Raphanus sativus
(Radish)
Germination
When a seed starts to sprout pH
How alkaline or acidic a substance is
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3. How does pH affect germination?
pH affects germination because the acid breaks down the seed coat and allows more water to get absorbed
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4. Temperature affecting Germination
If temperature is too high, moisture evaporates from the soil
If temperature is too low, water absorption slows
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5. Why Do The Experiment?
More areas we can grow food, the more food we can grow
The purpose of the experiment was to find the pH level and temperature that would cause the most Raphanus sativus (radish) seeds to germinate
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6. Problem
How do different levels of pH and temperature affect the germination of radish seeds?
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7. Hypothesis
If the surrounding temperature is 35ºC and the pH level of the water sprayed on the seeds is 4.0, then the most radish seeds will germinate
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8. Values pH Temperature (°C) - + 4.0 6.0 8.0 28 30 35 Standard
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9. Materials Source of tap water Analytical balance 100 mL spray bottles
Paper towels
Ziploc bags
Incubator (35°C)
Refrigerator
pH test strips
tweezers
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10. Procedure
We mixed the water with either baking soda or citric acid to change the pH and get a high, a low, and a standard concentration
We sprayed the concentrations onto the radish seeds placed in Ziploc bags
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11. Procedure
We then placed the bags into areas with the different temperature levels
After 3 days, we recorded the number of seeds that germinated in a table
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12. Procedure
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13. Data Analysis
The effect of pH on the germination of radish seeds was units
On average, as pH increased, the number of seeds germinated decreased by 0.17 units
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14. Data Analysis
The effect of temperature on the germination of radish seeds was 0.5 units
On average, as temperature increased, the number of seeds germinated increased by 0.5 units
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15. Data Analysis
There may be an interaction between the two line segments because they are not parallel
The effect of the graph is 0.16 units
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16. Observations Date Observation March 29 April 1 April 2 April 5
Bags and seeds are set up
April 1
All standards have germinated and quite a few of the ones in the incubator. No germination in the refrigerator
April 2
More have germinated in the incubator. Still no germination in the refrigerator
April 5
Still no germination in the refrigerator. We will retry this part in warmer area of 28°C
April 11
Seeds germinated in the warmer temperature
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17. Hypothesis Hypothesis was accepted
Most seeds germinated in 35°C temperature and pH level of 4.0
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18. Recap
Set out to find what pH level and temperature germinated the most seeds
We hypothesized that most seeds would germinate at 35ºC and a pH of 4.0
Conducted experiment
Sprayed different pH levels on radish seeds
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19. Recap Set the seeds in areas of different temperatures
Recorded how many seeds germinated after three days
Found a temperature of 35°C and pH of 4.0 germinated the most
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20. Design Flaws and Errors
Testing in an area of 22°C was too cold
Retested in an area of 28°C
Initially added too much citric acid and baking soda
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21. Further Study Different levels of pH Wider ranges of temperatures
Different types of plants
Different soil types
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22. Real Life Application Retailers find best source to buy stock
Profits increase
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23. Questions?
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