Jacob Strayer

Project

Presentation

Progress Log

Capstone Essay

Jacob Strayer

Mr. Caballero

H English 8

April 20, 2020

Watermelons

Watermelons are an amazing fruit that have changed throughout time, and have spread from their beginnings in Africa to the rest of the world. For my capstone project I will be creating a montage of different ways to destroy these amazing fruits. I wanted to do this for my project because I’ve always liked doing science experiments, such as growing minerals or making baking soda and vinegar volcanoes. Once I saw a trebuchet launching fruit at the mini-maker faire at OMSI and it really caught my attention. I wanted to take this to the next logical step and see how many ways I could destroy watermelons. For my research, I will explore the history, science, and farming of watermelons.

Watermelons originated in South Africa in 5,000 BC where it still grows in the wild today. They were originally bland and bitter, with a width of two inches. They were valued for their ability to store water especially when people needed to cross deserts. It is believed to have first been farmed in 2,000 BC in Egypt as a way of storing water as seen in hieroglyphics and remains of watermelon seeds in the tombs of the kings (Strauss). Watermelons spread to India, and eventually China, in the 7th century. In the 10th century, the Moors brought them to Mediterranean Europe and the Greeks used them for their healing properties (“History) to treat heatstroke (Strauss). In the 16th century, slave trade and British colonists brought them to America. They were first grown in Florida, and later spread to Massachusetts in the 17th century. From there they spread to the pacific islands by captain James Cook (“History).

Along the watermelon’s centuries of travel, watermelons have changed to become much larger and sweeter than their bland and bitter ancestors (Strauss). They are now about 90% water and 6% sugar (“History). Their scientific name is Citrullus lanatus and they are part of the cucurbitacecae family which is composed of fruits that are grown on vines. Watermelons are also classified as a type of berry called a pepo ("Watermelon."). The red color of watermelons is caused by a chemical called lycopene which is a powerful antioxidant and is also what causes the red color in tomatoes (“The Chemistry). Lycopene helps prevent certain types of cancer and heart disease (Wolf). The watermelon aroma is thought to be caused by C and C₆ aldehydes, with the most significant being (Z,Z)-3,6-nonadienal. This took scientists a long time to figure out because when they collected the compounds the aldehydes had already fermented into alcohols causing scientists to believe that C₆ and C₉ alcohols caused the watermelon aroma instead of C and C₆ aldehydes. Watermelons also contain citrulline, which is turned into the amino acid, arginine, once it is consumed (“The Chemistry). Arginine helps our body heal faster, helps with cell division, and the removal of ammonia (Wolf). Watermelon’s ability to store water, multiple health benefits, and their sweet taste, have made them a popular fruit that is now grown all over the world.

Watermelons prefer to grow in a semi-arid climate. They can grow in a humid environment, but will easily develop fungal infections. Their growing season is long, taking from 70 to 85 days to mature (Morse). Recently, a new growing technique from Pacific Trellis was developed, which involves growing watermelons vertically on tall poles or trellises, and in a shade house. This causes less water to be wasted and improves the appearance and quality of the watermelon by shielding them from the sun, wind, insects and disease invasion (James). This farming style also uses less land and extends the growing season by keeping the watermelons cool in the summer by providing shade, and warm in the winter by keeping warm air in (Jett). Growing watermelons on poles and in shade houses also yields 30% more watermelons than traditional methods because this method provides more protection for the watermelons (James).

One way that humans have impacted the cultivation of watermelons is with the creation of the seedless watermelon. Seedless watermelons were first made in 1951, by Professor H. Kihara from Japan. Since they don't create mature seeds, their seeds are artificially created by crossing a diploid watermelon with 22 chromosomes, and a tetraploid watermelon with 44 chromosomes (“Where), which is created by exposing a watermelon plant to colchicine (a chemical gotten from crocuses which causes the watermelons chromosome to double), resulting in a sterile triploid watermelon with 33 chromosomes. When this triploid watermelon plant produces seeds, its seeds can not mature fully and instead stay white and small. This is like crossing a donkey and a horse to create a mule, which is also sterile, but instead of crossing a donkey and a horse you cross two watermelons (Rupp). Commercial production started in the 1990’s but seedless watermelons weren’t as sweet as seeded watermelons, until plant breeders improved their sweetness and flavor. Nowadays, seedless watermelons make up about 92% of the retail market for watermelons (“Where).

From my research I learned about where watermelons originated from and how they traveled from Africa to the Mediterraneans, Asia, and eventually, the Americas. I also learnt about the chemical composition of watermelons and some of the health benefits of eating watermelons, as well as a new farming technique that uses less water and land, but produces a higher yield. I found it interesting how the principles behind creating seedless watermelons and breeding a mule are similar. Using what I have researched, I can take precautions when I destroy watermelons, for example, since watermelons are 90% water, when I use heat to destroy a watermelon I need to make sure it doesn’t splatter everywhere and burn people nearby when the water boils by staying away from the watermelon and putting a tarp on the ground to easily clean up the mess.

Works Cited

“History of Watermelon.” Vegetable Facts,

www.vegetablefacts.net/vegetable-history/history-of-watermelon/.

James, Chandler. “Pacific Trellis Innovates Watermelon Growing.” Andnowuknow, 31 Oct. 2019,

m.andnowuknow.com/behind-greens/pacific-trellis-innovates-watermelon-growing-Josh-Leichter

/chandler-james/65590.

Jett, Lewis W. “High Tunnel Melon and Watermelon Production.” University of Missouri Extension,

​extension2.missouri.edu/m173.

Morse, Sarah. “What Environment Does Watermelon Grow Best In?” Home Guides | SF Gate,

homeguides.sfgate.com/environment-watermelon-grow-in-69285.html.

Rupp, Rebecca. “Watermelon May Be the Most Unnatural, Yet Delicious Fruit.” National Geographic, 7

Aug. 2015,

www.nationalgeographic.com/culture/food/the-plate/2015/08/07/watermelon-may-be-the-most-u

nnatural-yet-delicious-fruit/#close.

Strauss, Mark. “The 5,000-Year Secret History of the Watermelon.” National Geographic, 21 Aug. 2015,

www.nationalgeographic.com/news/2015/08/150821-watermelon-fruit-history-agriculture/#close.

“The Chemistry of Watermelons: Colour, Aroma, & Explosions.” Compound Interest, 9 June 2015,

www.compoundchem.com/2015/06/09/watermelon/.

"Watermelon." Britannica School, Encyclopædia Britannica, 3 Aug. 2015.

school.eb.co.uk/levels/intermediate/article/watermelon/76268. Accessed 8 Apr. 2020.

“Where Does Seedless Watermelon Come from?” Watermelon.org,

www.watermelon.org/the-slice/where-does-seedless-watermelon-come-from/

Wolf, Zoe. “The Chemistry of Watermelon.” ChemistryIsLife.

www.chemistryislife.com/the-chemistry-of-watermelon.