Sharon Lab

With the addition of Natron as a herbicide to control weeds, there are concerns that the runoff could affect the growth of other plant life. The purpose of this lab is to test the toxicity of Natron as well as the max dosage that will still allow for beans to grow in the presence of the herbicide; We hope to find out the LD50, the toxicity in comparison to Anubis, as well as the germination rate of exposed the beans. We hypothesized that increased concentration of Natron would lead to a decrease in the germination rate. Our null hypothesis formulated that there would be no correlation between exposure and germination.

In order to test Natron at various concentrations, we set aside 5 petri dishes for five concentrations: 0% (control), .5%,

Our control theoretically should have had a higher germination rate than the .5% concentration, but it had a 30% lower germination rate, or 3 beans. We noticed the beans without natron were noticeably healthier and had longer and larger sprouts than those with natron. Additionally, experiments conducted by our peers suggested that the control produced a higher germination rate than those exposed to Natron. This led us to believe there were bad beans in the control group that caused the lower germination rate rather than Natron aiding the growth of the beans. We are doubtful that it was error on our end that caused the failure for we were very meticulous. With the outlier aside, we noticed that as we added Natron at higher concentrations led to less beans being sprouted. From .5% to 1% there is a huge drop off as it goes from 80% germination rate to a 0% germination rate. Based on the data .5% is preferred concentration for exposure, however we cannot confirm this for sure. In future experiments we would use 50 beans in a larger petri dish with the interval going up .1 percent from 0% to 1.5% (15 total petri dishes, 750 total beans). This would allow us to more precisely find where the drop off occurs and the larger bean count would give us a more accurate germination rate. Based on the LC50’s of Anubis (.1) and Natron (.675), Anubis is more toxic as the LC50 is lower, and therefore it requires a smaller dose to have a 50% death rate. Based on this data Natron is a preferred solution for a herbicide for agricultural use because of the higher LC50. However, it should be noted that using Natron will negatively affect the growth of