Aspirin Plants
Christian Thorson
Mulgrave School
Floor Location : J 233 V

The purpose of this experiment is to determine the effects of Salicylic Acid (SA) (applied through aspirin) when given to a scarlet runner bean (Phaseolus coccineus) in 3 different levels of concentration. The choice of this experiment was determined by interest/curiosity on the impact of SA on plant growth. The hypothesis in this experiment was: "If multiple different levels of aspirin (as a source of salicylic acid) solutions are applied to a plant, then the plant will grow more when exposed to more salicylic acid, because salicylic acid has a positive effect on a plant’s growth due to how Salicylic acid is found in plants, strengthening their immune system."

To test this, four different sets of three plants were used. The different groups got: 1 tablet of aspirin per 7.6 litres of water (roughly equal to 2 gallons), 2.5 tablets of aspirin per 7.6 litres of water, 4 tablets of aspirin per 7.6 litres of water, and no tablets (control group). Each plant was watered for 12 days.

The results of the project show a general upward trend between the 4 groups of plants. The group of plants that acquired the most aspirin grew the fastest (with one exception) compared to the other groups, then the 2.5 tablet group, then 1 tablet and the control group. However, there were a few problems in the growth that impacted the results negatively. As mentioned previously, one of the plants in the group receiving 4 tablets germinated a day late, skewing the results. More importantly, some of the plant's roots were unable to break through the decomposable container that they started in (both the container and plants were put in a larger pot later in the experiment. As such, the plants may have not grown to their full capability.