Student’s research on coffee plants grows from family ties
GREENWICH — Four years ago Edgar Sosa, 19, said goodbye to his grandmother and mother in La Granadilla, Guatemala, and moved to be with his father in Greenwich.
He had not seen his father since he was 2 years old, and although leaving his family in Guatemala was hard, it was exciting to see his dad again.
Now a junior at Greenwich High School, Sosa has not forgotten where he came from. In fact, his past is driving his present studies. In his science class, Sosa is researching how to save coffee plants on Central and South American farms from dying of the rust fungus. The fungus thrives in the hot, humid environment and kills the plant essentially by suffocating it.
The research is deeply personal for Sosa. In 2012, his family tried to get into the coffee growing business, a major export of La Granadilla, and he was taught how to run the operation so he could take it over eventually. But the source of income dried up, along with the plants, when the rust fungus killed off their crop.
That experience would give Sosa an idea that would change the course of his high school career years later.
While in Andy Bramante’s English as a Second Language chemistry class, he noticed Bramante’s Honors Science Research students working on their projects and asked the teacher questions about their projects and the program.
Their conversation turned to coffee and the fungus that killed Sosa’s family’s crop. Bramante asked Sosa if he wanted to take the honors class, but the prospect of taking a challenging class not geared toward ESL students scared Sosa at first.
“I’ll think about it,” he told Bramante.
As soon as he knew that he would meet the requirements, however, Sosa got to work. He did not have a plan or abstract of what he would set out to do.
“I just wanted to stop the fungus and that was it,” he said. “I didn’t know how.”
He made do with lessthan-ideal circumstances: He could not experiment with the actual fungus — it is banned in the U.S. — or replicate Guatemala’s hot, humid conditions.
But he did find a journal article that demonstrated how nanoparticles can stop a fungus from killing plants. It was written by Wade Elmer, the head of the Department of Plant Pathology and Ecology at The Connecticut Agricultural Experiment Station. Sosa decided to replicate Elmer’s work on coffee plants, and eventually, they met and started working together.
When the two met, Bramante
said, “It was so wild to watch this guy’s (Elmer’s) jaw hit the floor.” The scientist was impressed with Sosa’s enthusiasm for agricultural science, when there are not that many young people who share that passion, and with the amount of work he had done already.
“Andy gives me the best,” said Elmer, who has worked with other HSR students.
“Edgar was really outstanding; he was very intense. If we didn’t have COVID-19 right now, he would be in the greenhouse setting up a new experiment,” he said.
They isolated a pathogen called alternia — a common fungus — that behaves similarly enough to the rust fungus to be used in experiments. They infected the plants and discovered exactly how the fungus grows and kills the plant.
“Before, we used to think that the fungus attacked the outer leaf and sucked all the nutrients from the plant,”
Sosa said. “The fungus is actually creating a biofilm and killing the plant by suffocating it.”
The cure is a spray of tiny copper particles. (To visualize a nanoparticle, Elmer said, imagine being in space and comparing a basketball to the Earth. That basketball is a nanoparticle.)
Three factors determine how sick a plant gets: the disease, the conditions the disease thrives in and how susceptible the plant is. Often, plants growing in nutrient-poor soil do not have high enough levels of certain micronutrients, including copper, to have a strong immunity to these diseases.
Sosa and Elmer developed sprays containing metallic nanoparticles to deliver micronutrients to the coffee plants, which the plants absorb through their leaves. The plants were wrapped plastic and placed under high-intensity lamps.
Three days later, the copper-treated plants were healthy and vibrant green, while the untreated ones were brown and all but dead.
“It was really striking,” said Elmer, who added he intends to write up the study for an online publication.
Sosa submitted his findings to science fairs, excited about his findings, but worried that his English — even after four years — would hold him back from communicating his ideas well.
“Even the day of the presentation for the science fair, I got to a point where I felt like I couldn’t do it,” he said. “But when I saw Mr. B, and all he has been doing for me, I realized I worked a lot and I had to do it. I couldn’t waste all that time for nothing.”
Bramante also worried for Sosa about the discussion portion.
“But it was awesome,” he said. “He was slow and methodical, and did a good job.”
In the Connecticut Science and Engineering Fair, Sosa’s project won him a substantial scholarship to the University of Hartford, third place in the Environmental Sciences category, first place in the Future Sustainability category and an invitation to compete at GENIUS Olympiad.
Explaining his project in English was one hurdle. Relaying it to his parents was another.
“You have to make it really, really simple,” he said.
The day he finished his poster, Sosa said he was really excited, but that did not register with his father.
“I can understand that — they don’t understand what a science fair is,” he said, adding that in Guatemala, “We were so far away from that.”
But, they are proud of him, he said.
“I told my mom I presented a project and that I got a scholarship, and she couldn’t believe it. They are very excited.”
Sosa’s next step is to keep researching. He wants to experiment with the real fungus, but he would need to go back to Guatemala or find someone who can try his experiment on the plants for him. He is starting to think about college, and in addition to the scholarship opportunities at the University of Hartford, he said he is also excited about a multi-cultural coffee agriculture program at the University of California, Davis.
Despite two years of balancing school with research into plant disease immunity, he does not drink coffee — here in the States, that is.
“The coffee is not as strong in Guatemala,” he said. “If you drink Colombian coffee and Italian coffee, Italian is stronger, and that’s the reason I don’t drink it. Since we produce it, we can drink it really fresh.”