A new cohort of Ph.D. candidates will begin their work on an interdisciplinary agricultural data science research endeavor this fall. The Sweet Fellows, aptly named for the sweet potato Analytics for Produce Provenance and Scanning (Sweet-APPS) project, will use a combination of operations research techniques, geospatial analytics and sensing technologies to develop machine learning algorithms that aim to reduce agricultural waste and increase the yield of U.S. sweet potatoes.
Designed by Biological and Agricultural Engineering research assistant professor Daniela Jones and funded by the U.S. Department of Agriculture National Needs Fellows program, Sweet Fellows brings together a group of talented researchers with varied knowledge and experience. “We usually put together people with similar backgrounds to solve a problem, but when you bring in people from diverse experiences and disciplines, they come up with different ideas to solve the same problem,” she says. “The broader research question that the Sweet Fellows will be trying to answer is yield, defined as quantity and quality, and to figure out the drivers that make sweet potatoes a certain shape and size.”
The project is important to North Carolina’s agricultural economy as the state leads the nation in sweet potato production, growing over 60% of the nation’s supply at an estimated value over $324 million. Sweet potatoes vary in shape and size more than any other fresh produce item. Overly small, large or misshapen potatoes can be reduced in price by as much as 80-90% of the value for U.S. sweet potatoes.
“Agriculture will see significant opportunities for adopting even greater technology in the next few years,” says Garey Fox, professor and head of the Department of Biological and Agricultural Engineering. “Our department trains a diverse cohort of biological and agricultural engineers that can take that innovative technology to develop decision support tools through a systems analysis to help growers make informed decisions.”
Sweet Fellow: Shana McDowell 
Meet Shana McDowell, a mathematician and North Carolina native, who will be working on a Ph.D. in biological and agricultural engineering.
Mathematics came naturally for Shana early in her education. She recalls friendly competition with her peers in a high school math class made learning fun.
“Undergrad exposed me to more,” she says. “That was where the understanding of how to solve a problem, then adding a real-world scenario to better understand concepts.”
Shana pursued a bachelor of science in pure mathematics from Fayetteville State University, and a master of science in applied mathematics from N.C. Central University.
While in graduate school, she prepared students for college mathematics in Hoke County Schools and the Wake STEM Early College — a joint program between NC State University and Wake County Public School System. Following a quantitative internship at Duke University, she became a senior data tech at the Duke Human Vaccine Institute, where she created an image classification program for the HIV spike protein.
“Scientists take pictures using an electron microscope that results in thousands of images,” she explains. “They try to get different orientations of the spike to build a 3D reconstruction so they are able to better study the spike structure.”
Using a convolutional neural network (CNN), the images are used as input and fed into the CNN layer by layer as the algorithm identifies patterns that are used to classify the images into different categories.
In her SweetAPPS research, Shana will look at the sweet potato supply chain. Jones, who will also be Shana’s Ph.D. advisor, says Shana will examine the supply chain ”from the field all the way to the packing facility, and hopefully beyond and into sweet potato national and international markets. Her experience will help us understand how all of the information gathered at each of those locations works together so that we can build an algorithm to make predictions.”
“I’m excited to do work that hits so close to home,” Shana says. “Whenever you’re going into research you hope that what you’re doing will have an impact on society, and this is an opportunity for me to contribute in that way.”
Sweet Fellow: Enrique Pena Martinez
Meet Enrique Pena Martinez, an NC State alumnus in biological and agricultural engineering, who will be working on a Ph.D. in electrical and computer engineering.
From a young age, Enrique knew he wanted to study agriculture. His grandfather, Manuel Arturo Pena, would plant vegetables in raised beds on the roof of his home where Enrique would spend hours watching the vegetables grow. He also credits his grandmother, Consuelo Ascanio Rodriguez, for encouraging him to pursue a career in agricultural engineering.
Enrique began his college education at home in the Dominican Republic, where he studied at the Santo Domingo Institute of Technology. From there, he entered a 2+2 partner program with Penn State, where he completed his undergraduate degree in biological engineering with the agricultural engineering option. Following his passion and desire to continue his education in agriculture technologies, he found and completed the master of science in biological and agricultural engineering at NC State.
A portion of Enrique’s research focused on refining cotton replanting recommendations using unoccupied aerial systems (UAS) and assessing the accuracy of manual versus UAS counts. The results from his research are being reviewed for publication in The Journal of Cotton Science and Transactions of the ASABE.
Enrique’s research for the SweetApps project will focus on applying machine learning and imaging tools towards measuring the size and shape of sweet potatoes at high-speed and at high-throughput in field conditions.
“Enrique’s experience applying technology solutions, such as drone imaging for improving cotton management, has given him a background in both engineering and working with stakeholders,” says Michael Kudenov, Electrical and Computer Engineering associate professor and Enrique’s Ph.D. advisor. “This will be invaluable as we develop methods that can enable size and shape phenotyping data that can be located to specific areas within a given field. This will support many facets of the project.”
“I want to be able to connect all of the different applications that are being developed,” Enrique says.“The research that I will be developing will actually bring money to many sweet potato farmers because there is a direct translation with added value on size and shape of sweet potatoes.”
Sweet Fellow: Randi Butler
Meet Randi Butler, an environmental scientist from Atlanta, Georgia, who will be working on a Ph.D. in geospatial analytics.
Naturally curious, Randi recalls an interest in science that led her to seek out explorer books when she went on shopping trips with her mother, Venneta Montgomery, who Randi also credits as her biggest cheerleader.
Randi began playing the violin in middle school and had to choose between her love of music and science as a college freshman. “I always knew I liked nature.” she recalls. “[Columbus State University] had a bachelor’s in geology … that was the stepping stone to get into environmental science.”
Randi graduated from Columbus State University with a bachelor of science in geology, then earned a master of natural resources in hydrology from the University of Georgia.
During her graduate studies, Randi interned at the USDA Natural Resources Conservation Service and the U.S. Environmental Protection Agency. She worked directly with landowners to improve irrigation systems and prevent soil erosion throughout Georgia and Alabama.
Shortly after graduation she was hired by the EPA to work with the National Pollutant Discharge Elimination Systems division, eventually overseeing development of a model tracking data across eight states on industrial stormwater discharge. She also worked with the Tennessee Department of Environment and Conservation while at the EPA, overseeing the state’s water monitoring program. In her last position, she evaluated international data on water quality with the Army Corps of Engineers at the Army Geospatial Center in Alexandria, Virginia.
Randi’s research for the SweetAPPS project will be analyzing satellite remote sensing data to better understand sweet potato production trends. “Randi has excellent experience working directly with farmers,” says Natalie Nelson, Biological and Agricultural Engineering assistant professor and Randi’s Ph.D. advisor. “In addition to data analysis, she’ll be able to bring in a rich perspective of what are on the ground challenges.”
Randi says she’s dreamed of getting a Ph.D. since she was a kid. “I enjoy the aspect of learning and seeing things from different perspectives … and with a Ph.D, for me, it can bring me more information to provide to others.”
Bridging Gaps in Diversity
The process of recruiting underrepresented students was particularly relevant for the SweetAPPS project. “As agricultural jobs shift beyond the farm, without intervention, the growing agricultural data science workforce will most likely lack diversity, similar to other high-paying, family-flexible and secure jobs,” says Jones.
According to Pew Research, Black and Hispanic workers make up a smaller percentage of STEM workers compared to their share in the U.S. workforce as a whole. “It is very rare for me to see me in my field,” says Randi, “It’s a welcoming thing to see that I’m in a diverse group because I do see me, or I see a piece of me, and it makes me feel like we could get this done.”
When asked how they felt their role would impact other historically underrepresented students who want to pursue advanced degrees, each of the Sweet Fellows expressed a sense of responsibility representing their respective communities.
“I’ve gotten comfortable with being uncomfortable. I’ve gotten comfortable with being the only me in certain programs, but I’ve been afforded the opportunity to be a part of the Sweet-APPs team,” says Shana, “so there’s a reason why I am here.”
Jones says she and others with the SweetAPPS team’s are “extremely excited for the tremendous talent that Shana, Randi and Enrique bring to the team. Our greatest goal is that we provide them, and all of our students, with a welcoming and inclusive community of scholarship that nurtures their talent and lets them thrive to their fullest potential.”