Purpose:
The reason that I want to conduct this experiment is because I want to test the correlation between the amount of light that a plant is exposed to, and its taste. I am guessing that the amount of light, when increased, will lead to a stronger or sweeter taste.
Predictions:
I expect that planters one and two will grow the quickest, as well as have the most vibrancy and taste, as they are being subject to a large amount of light specifically manufactured to help plants grow.
I expect planters 3 and 4 to do fine as well, however less so than 1 and 2, as they only have the somewhat limited natural light of the green house
I expect planter 5 to do the worst, as it has a large amount of its sunlight restricted by a perforated sheet of tin foil.
There are 4 different types of of microgreens in the plant mix:
Broccoli, kale, kohlrabi, and cabbage
According to the individual grow rates of each pant, the Broccoli should grow the fastest, the kale and cabbage should grow around the same rate, and the kohlrabi should grow the slowest through the differences should be only 1-2 or so days in growth
Observations:
Planters 1-2
These two planters were the ones that were exposed to the grow lights, they started out slow, and were the shortest, however, they became by far the most vibrant and strongest, with the stalks being so thick that they were able to pick up a stick off the bottom of the planter bed.
Planters 3-4
These two planters were exposed to natural light. They started off by growing very quickly, reaching towards the light at the lip of their planters. However, once they reached the sun more directly by growing to the top of their planters, they began to grow quickly, becoming strong and vibrant, though not as much as the first two planters.
Planter 5
This planter’s light was limited, covered in a sheet of tin foil with a few holes poked in the top. This was by far the most interesting planter, and although the stalks were by far the thinnest, they were taller than the others by far. I felt like I was competing with the plant to keep the tin foil high enough that the leaves wouldn’t poke out of the top.
Planter slide show Pictures
Measurements:
Day 2 is 5 days after the initial planting, and the first day that the plants had enough height to be measured meaningfully
Plan for taste testing:
Give each person 3 cups, one with plants from the first two planters, the second with plants from the second two planters, and the last with plants from the third planter.
Ask each person to compare them
Tell the person they were grown under different light levels, and ask them to guess which batch was grown in which light level
How to test glucose:
Take a group of leaves from a sample and shred them by hand with gloves on, then put the leaves into a small container with boiling water and stir for 10, then take the distilled water with the leaf and 1 ml of it per 2.5ml benedict's solution, then put the solution in a boiling water bath for 5 minutes
Observe the color changes and record them with the table
Qualitative Taste Test results
Many of the participants noted that Samples 1-2 were more chewy than the other samples, with a stronger bitter taste one described as ‘peppery’
Samples 3-4 seemed to be the favored taste among the participants described as less chewy than samples 1-2 and with a more ‘full’ taste, also noted to have a strong after taste
Sample 5 was noted to be the most tasteless sample, and either described as simply bitter or without taste altogether
When given the differences in the samples (light level) but not told which sample corresponds to each level of light the participants were asked to guess which light level went with each sample. 2 of the participants were able to correctly surmise all 3, yet the other two were not, one switched samples 3-4 and 5. The other switched samples 1-2 and 3-4
Sources of error:
Some potential sources of error include the fact that samples 1 and 2 were also exposed to some sunlight, as well as samples 3-4 likely enjoying some of the reflected grow light’s rays
I wasn't able to access the samples the 3rd day after they were planted and as such unable to begin their measurement and growth, thus between days 1 and 2 there is a day of discrepancy
Furthermore, in the taste test, participants tasted samples differently, some took a pinch of each, another simply ate the leaves, in the future if this experiment were repeated I would advise instructing the participants to each take a pinch
The soil in each planter was at a slightly varied height, leading to marginally different exposure to light
We weren't able to control what amounts of each different plant the participants grabbed in their tastes, as the seeds were mixed in the bag.
Concluding remarks:
In the end, my hypothesis was quantitatively correct, there was more sugar in the grow light sample than in the others followed by the natural light samples and lastly the limited light sample. Though qualitatively people say that the grow light samples were the most bitter. The experience was informative, and the limited light sample’s growth in particular was a joy to watch. I felt like I was competing with the plants to keep them in a limited light environment despite their best efforts to grow through the holes in the top of their tin foil. It was also fascinating to see how the ease of access to light affected their early growth, given that light shone directly into grow light samples, they started very short and stayed the shortest, whereas the natural light samples had to grow taller initially to poke out from the planter to gain fuller access to sunlight.