Two of the state’s iconic foods could potentially pair well together long before landing on your dinner plate.
Researchers at the University of Maine are currently exploring using lobster shells to combat soil pathogens in potato fields. Potatoes are a root crop, making them susceptible to soil borne diseases such as early dying syndrome. The fungus responsible for the disease is present in Maine soils and can wipe out half an annual crop.
Together, potatoes and lobster were responsible for more than $900 million in value to the state’s economy in 2021, according to state and national agriculture statistics. The researchers at UMaine want to create a shell-to-spud combination to boost the viability of both the tubers and the crustaceans.
Katie Ashley, a plant science doctoral student at UMaine, is working under the hypothesis that the correct concentration of the compound chitin can prevent these fungal diseases. About 75 percent of a lobster’s shell contains chitin, one of the most abundant polysaccharides in nature, second only to cellulose.
Chitin is also found in fungal and bacterial pathogens. Ashley is working to weaponize the compound by adding lobster shells to potato fields in the fall. She is hoping the addition of chitin in the fields will promote the growth of specialized microbes that can create a line of defense against soil-borne diseases.
“We’re very fortunate to have both rich agricultural production and a blue economy [because] it puts Maine in a very unique position,” said Ashley, who earned her master’s in plant pathology from UMaine. “This presents an opportunity to connect the potato and lobster industries and utilize shellfish byproducts, which would otherwise enter the waste stream.”
The concept would also provide a new market for byproducts of the lobster industry. According to the Maine Department of Marine Resources, the industry landed a 100 million-pound catch in 2021.
Curt Brown, a marine biologist at Saco-based seafood supplier and processor Ready Seafood, estimates that shells account for 25 percent of lobsters’ weight. Nearly half of Maine’s catch is processed rather than sold live, and those shells are largely destined for landfills. A new market for this byproduct would ebb that waste stream.
Ready Seafood contributed lobster shells for Ashley’s study.
“This research has the very real potential to turn a waste stream into a revenue stream for Maine’s lobster industry, while at the same time helping to increase the value of another iconic Maine product: the potato,” Brown said. “I can’t think of a better example of a true win-win scenario for our state.”
If successful, Ashley’s approach could provide an alternative disease control practice for Maine potato growers. Chemical inputs are the largest operating expense for the state’s growers, according to a 2008 report from the Maine Potato Board. Some, such as chlorothalonil — which has been used since the early 1970s to control late blight — have been the subject of increasing scrutiny and regulation.
“Reducing the reliance on pesticides for disease management in favor of enhancing microbial soil ecology could benefit both agriculture and the environment,” Ashley said.
Also working on the project is Ross Sousa, a fourth-year botany major and laboratory technician.
Chitin from other types of shellfish, including oysters, is already being used in integrated pest management programs on farms in South Korea, Japan and California. The UMaine team’s study is the first to use Maine lobsters in potato growing practices.
The team completed a greenhouse trial with 90 plants on UMaine’s campus this fall. A field-scale trial in the 2023 growing season will compare plots with different concentrations of chitin, compost and chemical fumigation at Aroostook Farm in Presque Isle.
