||We know the basics on how to care for a plant, and we have all taken biology and learned about the plant cell. In our botany class, we have learned about the basics of plant diseases, and how they are spread. We also know the plant disease triangle.
We are interested to learn about how the different aspects of the disease triangle can be manipulated to change how the disease spreads. We also want to learn what can be done to treat plant diseases.
||How does the amount of moisture in the environment that the potato is in change how the potato soft rot develops in a potato?
In the initial experiment we were instructed to put the potato in the bag with damp paper towels. We were curious about how the difference in moisture might change the experiment.
We know that environment is a factor in how plant diseases develop, so if we change the environment it may change how the disease develops.
||We predict that if there is more moisture in the environment, then the disease will be more widespread in the potato. We think this because in the disease triangle, the environment is essential to the development of the disease. The damp paper towel was the environment for our initial experiment, so moisture may be an important factor in the development of potato soft rot. We think that with increased moisture, the potato will have larger areas with soft rot. However, in an environment with no extra water, the disease will not spread as much through the potato.
||1. Follow the steps of the initial experiment in order to inoculate the potato with the disease at the poles and the sides.
2. Take a gallon resealable bag and place 2 paper towels at the bottom.
3. Measure 20 mL of water in a graduated cylinder and pour it into the bag on top of the paper towels.
4. Place the inoculated potato into the bag and fold the paper towels around the potato.
5. Push the air out of the bag an seal it.
6. Repeat steps 1-5 decreasing the amount of water by 5 mL for each bag until you make a bag with no water ( 5 bags total)
7. After a week, cut open the potatoes in order to see a cross section of the inoculation points.
The independent variable is the amount of water in the bag. The dependent variable is the amount of soft rot in the potatoes. We will record the date by taking pictures of the cut open potatoes and placing them side by side to compare the visible areas of infection.
||We accept our hypothesis. As the amount of water in the bags increased, the appearance of soft rot also increased. The 10 mL potato, however, was an exception because it has multiple areas of corking, minimal soft rot, and a lot of sprouting on the outside. The potato with no water also has sprouting on the outside, although not as much. We concluded that more water helps soft rot develop. Another conclusion we came to, although unintended, was that if the potato produces corking and defends itself, then the more water will increase the amount of sprouting. Corking is what the potato produces to defend itself. We assume that the 10 mL potato was older and therefore more able to defend itself. The potato that was in a bag with no water was our control. We could have improved our experiment by having two trials for each amount of water. This would have given us multiple examples for each variable, and helped with instances such as our results from the potato in 10 mL, which had sprouts and corking. Sources of error could have included the difference in mass of the potatoes, the age of the potatoes, and human error such as inoculation depth, amount of water measured, or incomplete closing of the bags.
||High School Students (Grades 9,10,11,12)
||Mercy McAuley High School