Science Buddies: "Ask an Expert"

Hi. My name is Jacob Turner and I am a student at Hawthorne Scholastic Academy. I have been working on a project over the summer. My project is titled: Is There An Organic Way To Kill Buckthorn? Once a week or every other week I have gone out to the St. Paul Woods and have poured .5 liters of lemon juice at the bases of three different buckthorn.
I have completed my experiment and would like your input on it.

On the smallest of the buckthorn, I have found maybe four or five light green leaves. All of the bottom branches of that buckthorn are bare as well.

On the two bigger buckthorn, there are a few clumps of shrivelled up leaves. I'm am pretty sure that this means I have had some success, but since you are an expert on this, I would like to get clarification.

Thank you so much.

Hi Jacob,
My brief (but probably unsatisfying) answer is that there is not enough information or data in your post for me to interpret of the results. Were there other bushes around that did or did not show the same pattern of shriveled leaves? Can you logically explain why the small plant was unaffected, while the larger plants might have been affected? Depending on the mineralogy of the soil, it can have a small or large acid buffering capacity, so it is difficult to say how much your lemon juice might have affected the pH of the soil. Is it possible for you to collect more data? For example, you could test the soil pH under treated and non-treated buckthorns, and take photos & observations of other buckthorns in the area.

Looking forward to hearing more about your experiment.
Chris

Hi,
The key here is you need to measure some "control" plants that did not get lemon juice. Try finding 10-20 of those and see what % have shriveled leaves.

Next time boost your sample size on the treatment group (with lemon juice) to something more like 10 or more.
Good luck
Roland

Hi Jacob,
I agree with the other Experts, more data would definitely give us more clues as to how we can answer your question in a more specific way. I would definitely a control like Roland said and I would also suggest you try varying the amounts of lemon juice and set up an experiment using many plants in several categories (each with a different concentration of lemon juice). Comparing all these results would give you a comprehensive data base from which you can hopefully draw your conclusion. Best of luck with your project!

ChrisG wrote:Hi Jacob,
My brief (but probably unsatisfying) answer is that there is not enough information or data in your post for me to interpret of the results. Were there other bushes around that did or did not show the same pattern of shriveled leaves? Can you logically explain why the small plant was unaffected, while the larger plants might have been affected? Depending on the mineralogy of the soil, it can have a small or large acid buffering capacity, so it is difficult to say how much your lemon juice might have affected the pH of the soil. Is it possible for you to collect more data? For example, you could test the soil pH under treated and non-treated buckthorns, and take photos & observations of other buckthorns in the area.

Looking forward to hearing more about your experiment.
Chris

Chris,

The plants around the buckthorn seemed unaffected

ChrisG wrote:Hi Jacob,
My brief (but probably unsatisfying) answer is that there is not enough information or data in your post for me to interpret of the results. Were there other bushes around that did or did not show the same pattern of shriveled leaves? Can you logically explain why the small plant was unaffected, while the larger plants might have been affected? Depending on the mineralogy of the soil, it can have a small or large acid buffering capacity, so it is difficult to say how much your lemon juice might have affected the pH of the soil. Is it possible for you to collect more data? For example, you could test the soil pH under treated and non-treated buckthorns, and take photos & observations of other buckthorns in the area.

Looking forward to hearing more about your experiment.
Chris

Chris,

The pH on the buckthorn I tested, was lower overall than the pH of other buckthorn in the woods.

staryl13 wrote:Hi Jacob,
I agree with the other Experts, more data would definitely give us more clues as to how we can answer your question in a more specific way. I would definitely a control like Roland said and I would also suggest you try varying the amounts of lemon juice and set up an experiment using many plants in several categories (each with a different concentration of lemon juice). Comparing all these results would give you a comprehensive data base from which you can hopefully draw your conclusion. Best of luck with your project!

The plants surrounding the buckthorn were completely unaffected.

ChrisG wrote:Hi Jacob,
My brief (but probably unsatisfying) answer is that there is not enough information or data in your post for me to interpret of the results. Were there other bushes around that did or did not show the same pattern of shriveled leaves? Can you logically explain why the small plant was unaffected, while the larger plants might have been affected? Depending on the mineralogy of the soil, it can have a small or large acid buffering capacity, so it is difficult to say how much your lemon juice might have affected the pH of the soil. Is it possible for you to collect more data? For example, you could test the soil pH under treated and non-treated buckthorns, and take photos & observations of other buckthorns in the area.

Looking forward to hearing more about your experiment.
Chris

As to the small plant, I mentioned in my paragraph that all of the lower branches on the smallest buckthorn were bare.

Thanks for the additional info. I think you are headed in the right direction. The more data (for example, photographs and measurements of plant height and biomass) you can collect to support your statements, the better your project will be. I have a couple of additional questions that might help to clarify things:

"The plants around the buckthorn seemed unaffected"
Do you mean other Buckthorns that didn't receive the treatment, or do you mean all types of plants?

"The pH on the buckthorn I tested, was lower overall than the pH of other buckthorn in the woods."
What methods did you use to test pH? How many samples did you take? What were the values of pH that you observed?

Thanks,
Chris

ChrisG wrote:Thanks for the additional info. I think you are headed in the right direction. The more data (for example, photographs and measurements of plant height and biomass) you can collect to support your statements, the better your project will be. I have a couple of additional questions that might help to clarify things:

"The plants around the buckthorn seemed unaffected"
Do you mean other Buckthorns that didn't receive the treatment, or do you mean all types of plants?

"The pH on the buckthorn I tested, was lower overall than the pH of other buckthorn in the woods."
What methods did you use to test pH? How many samples did you take? What were the values of pH that you observed?

Thanks,
Chris

Chris,

All of the plants that were around the buckthorn were completely unnaffected. I used a pH meter that I got at a gardening store to measure the pH of the soil. I measured the pH of the buckthorn before I poured the lemon juice and after I poured the lemon juice. The pH of the normal buckthorn was 6.5. The at the end of the project, pH of the experimental buckthorn was 4.5.

Jacob,
Thanks for the additional information. Your experiment sounds very well done. One complication is that your results include many qualitative observations, as opposed to quantifiable measurements, which can be a little tricky. Qualitative observations are descriptions from personal experience. Quantitative measurements are numbers based on measurements, for example, of plant biomass. The statement "All of the plants that were around the buckthorn were completely unaffected" is a qualitative observation and will raise some questions because it is open to interpretation. People might ask: What sort of effects were considered? Did you look at the roots of the plants? Was the growth of those plants compared to the growth of the same species of plants outside the treated area?

I can think of a couple of ways to approach this problem. One idea is to show people photographs of treated and untreated buckthorns. This will allow people to answer many of these questions themselves. Another way to approach the problem is to try to use quantitative measurements of numbers of leaves, biomass, or other indicators of plant health, and then compare the treated plants with untreated plants as a "scientific control."

Please let us know if you have any additional questions about this information or about what to do next.
Chris

Did you keep the same amount of lemon juice for all of the buckthorn plants? er.. if you did then the smallest one should have the most effect felt since the 2 bigger ones should have more strength. That's just a guess but good luck with your project! !

stanthescienceman wrote:Did you keep the same amount of lemon juice for all of the buckthorn plants? er.. if you did then the smallest one should have the most effect felt since the 2 bigger ones should have more strength. That's just a guess but good luck with your project! !

I did put the same amount of lemon juice on all of them. Thanks.

ok good luck winning