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The First Experiment: A Lesson in How Not to Germinate Seeds

Objective:

How does the concentration of magnesium in a radish plant's nutrient supply affect its growth?

Our hypothesis:

Radish plants require magnesium to grow, but they will not grow as well if they have too much magnesium.

Our prediction:

If radish plants require magnesium to grow, then the leaves of the plants with no magnesium in their nutrient supply will undergo chlorosis and the plants will die. If radish plants do not grow as well with too much magnesium, then the plants with double the magnesium in their nutrient supply will not grow to be as large as the plants with a normal amount of magnesium in their nutrient supply.

The Experiment

Bomb Boy and the Chemicals We mixed nutrient solutions according to Dr. Alan Cooper's formula in the manner outlined in S.H.A.R.P. Lesson Three. We made one nutrient solution with the amount of magnesium in the recipe, one with double the amount of magnesium in the recipe, and one with no magnesium at all. We were not able to find all the chemicals in the nutrient solution recipe, so we had to make calcium nitrate by doing an acid-base titration with nitric acid and calcium hydroxide. We also were not able to find any EDTA iron, so after much experimentation and frustration Josh was able to invent a procedure for making EDTA iron from EDTA acid and several other chemicals. This earned him the nickname "Bomb Boy."

We built three hydroponic apparatuses: one for the radishes with normal magnesium, one for the radishes with double magnesium, and one for the radishes with no magnesium. We built them according to the instructions in S.H.A.R.P. Lesson Four, Step One. We had built the hydroponic apparatuses a different way, but Ms. V said it wasn't going to work, so we changed the setup around and it worked fine.

Petri plate with germinating radishes Then we germinated our Cherry Belle Radish seeds, mostly following the instructions in S.H.A.R.P. Lesson Four, Step Three. We put cotton balls in four petri plates and put several seeds in each petri plate. We soaked the seeds and cotton balls thoroughly with water and closed the lid of the petri plate. We then left the petri plates in the sun and waited for the seeds to germinate.

Oops! Well, the seeds germinated, and soon our petri plates were full of little plants. We weren't really sure when to take the little plants out of the petri plates and plant them in the Perlite, so we made the mistake of leaving our baby plants alone in the petri plates without baby-proofing their environment. We left them in the greenhouse for the weekend, and by Monday they had grown so much that they had pushed the lid off the top of the petri plate. There had been water trapped in the petri plate keeping the little plants moist, and when the lid came off the water evaporated. Most of the plants did not survive this episode. But we learned from our mistake: In our next experiment, we rubber-banded the petri plates shut so the little plants would not grow, push the lid off, and dry themselves out.

But that was not the end of the experiment! We planted the surviving radishes in the Perlite and fed them the normal nutrient solution, and they grew and prospered. We decided to not attempt the experiment with different nutrient solutions since we didn't have very many radishes left.

Watch one pot of plants grow! Watch the whole experiment grow!

(caution: animations may take some time to load)

One big radish Our harvest of five radishes Roots growing out of the bottom of the pot

When these radishes were large enough to pick, we harvested five healthy-looking radishes. Though we did not put them in the water, we did refrigerate them, and we got twelve people to eat them and comment on their taste:

Ms. Nick eating a radish Ms. Nick: not as spicy Spencer Nicholson eating a radish

Spencer Nick: great

Tara Westfield eating a radish Tara Westfield: sweeter (than store-bought radishes) Mr. Hahola eating a radish

Mr. Hahola (radish lover): very flavorful

Emily Sielski eating a radish Emily Sielski: kind of bland, but with radish taste; gets a little spicier as you eat it, has a little kick to it Faith Hale eating a radish

Faith Hale: not as bitter as store-bought radishes, sweet and yummy, bitter aftertaste

Stephanie Hughes eating a radish Stephanie Hughes: same as if not fresh (?) Ms. V eating a radish

Ms. V: mild and sweet in flavor, no bitter aftertaste (but she prefers radishes with more spice)

Mr. Mazella eating a radish Mr. Mazella: good, tastes like radish, crisp Mr. Gibbons eating a radish

Mr. Gibbons: have a little bite to them, good, nice and fresh

Cuy Neugebauer eating a radish Cuy Neugebauer: spicy aftertaste, otherwise normal Matt Sisco eating a radish

Matt Sisco: tastes like a radish (ya-duh!)

Conclusion

While we were unable to find out anything in this experiment about how radishes react to magnesium concentration in their nutrient solution, we did find that radishes can successfully be grown using hydroponic methods. On top of that, the people who tried our hydroponic radishes generally liked them, so we can conclude that hydroponics is a generally viable method for growing radishes.

Return to Our Experiments With Hydroponics
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