A young entrepreneur by the name of Chase Hill, now the CMO at finishup.org, recently conducted an experiment with salt water and seed germination and the results were ground breaking.
Question: What is the maximum amount of salt in saltwater that will allow the seeds to germinate?
Hypothesis: The maximum salt level that will allow the seeds to germinate will be the 5 grams of salt solution.
Materials: 10 Petri dishes, a pipette, 100 seeds, distilled water, paper towels, salt, tape (for labeling the Petri dishes)
1) Place 10 seeds on a paper towel in each of the ten Petri dishes
2) In the first dish, apply 10 drops of only distilled water to the seeds. This will be the control.
3) In the remaining nine dishes, apply each of the nine saltwater solutions increasing by increments of 1g of salt for each- the first being 1g of salt mixed with 10 drops of distilled water, the second 2g, third 3g, etc. Label each of the dishes according to the salt solution that was applied.
4) Securely cover the Petri dishes and place them in an area. (An area of sunlight is not required)
5) Observe the dishes daily for three days, record results of which dishes allowed germination.
Control: Petri dish containing 10 seeds and 10 drops of distilled water
Independent Variable: Level of salt in each dish’s solution
Results: Over the course of three days, the seeds were able to germinate in the dishes that contained a 3g of salt solution or less. The first day, none of the seeds had germinated in any dish. In the second day of observation, only the seeds in the control dish had germinated.
All ten seeds had began to sprout. On the third day, there were six seeds that had germinated in the 1g solution dish, five seeds in the 2g solution dish, and three seeds in the 3g solution dish. There were no signs of germination in the remaining Petri dishes. We noticed the saturated paper towel in each dish had absorbed a green color and a pungent smell, almost like urine stains on tile & grout. Below is our data table and a visual graph of the results.
Analysis: Our results did not support our hypothesis. We thought that the seeds would be able to germinate in higher saline water (the 5g solution), but our results show that the highest level of salt solution that allowed seed germination was the 3g solution. Our results weren’t too far off from our hypothesis because we knew that there would be a certain level of salinity that the seeds would not be able to generate in.
Also, we noticed that it took three days for some of the seeds in the higher saline level Petri dishes to germinate. At this rate, we might have been able to see some signs of germination in dishes if we were to observe for 4 or 5 days. Our results were very similar to what we anticipated. As the saline level of water went up, the percent of seed germination went down.
Our control, which was distilled water with no added salt, had by far the healthiest and fastest germinating seeds. Then, as more salt was added to each of the different Petri dishes, the seeds took longer to germinate and didn’t look as healthy. This shows us that these particular seeds do not grow well with a salt water solution.
One uncertainty we had when observing day to day, was that we weren’t always able to tell if a seed had actually germinated yet. A lot of seeds had became swollen almost twice its original size, but had not yet began to split and sprout.
If we were to do this lab again with changes to further our findings, we would observe for longer than three days. Since on the third day we were still seeing new results, it would have been more accurate to test our question if we were to continue recording until no new results were seen day after day. Another alteration we would apply to this lab would be to decrease the interval of each saline level.
For example, instead of increasing by 1 gram of salt per Petri dish, we would decrease that to .5 grams or even .34 grams. The smaller the interval, the more accurate our conclusion will be to the exact amount of saltwater that would allow seed germination.
Overall, we conducted our experiment the way we designed it to be, and although our results differed from our hypothesis, they answered our question.