Professors Leslie Lekatz and Matt Simmons, who teach in the Department of Agriculture and Natural Resources at UMC, have partnered with a research project that investigates whether buckthorn seeds remain viable after passing through the digestive system of goats.
Buckthorn, native to Asia and Europe, was introduced to the United States in the 1880s as an ornamental plant used for hedges. The tree, which can grow to 20 to 30 feet tall and have a trunk circumference of 10 inches, produces abundant fruit in the form of berries. The birds carry the berries, which contain seeds that are distributed when the bird defecates.
The prolific plant is on the Minnesota Department of Agriculture’s Restricted Noxious Weed List.
Restricted noxious weeds are plants that are widely distributed throughout the state and are harmful to human or animal health, the environment, public roads, crops, livestock and other property, but which cannot be controlled only by prohibiting the import, sale, and transportation of propagated parts, except as permitted by specific Minnesota laws, according to the Minnesota Department of Agriculture.
Birds eat buckthorn berries like these in this photo taken October 28, 2021. After the berries pass through the bird, the seeds germinate where they were deposited. Ann Bailey / Agweek
Buckthorn has also spread to North Dakota, South Dakota, and Montana.
In Montana, buckthorn has been reported in at least 27 counties, according to Montana State University Extension. In 2017, the plant was placed on the state’s Noxious Weed List as Species 2A, meaning it is common in isolated areas of Montana.
Controlling buckthorn is difficult because it does not respond to several control methods, including herbicides.
Students enrolled in the UMC Natural Resources program unsuccessfully cut buckthorn in the Red River Valley Natural History Area near campus, then applied a herbicide to the stumps of the plant, but the invasive weed took hold. continued to spread, Simmons said.
“It’s very robust, very competitive,” said Simmons.
In addition to smothering native undergrowth in forest areas, buckthorn infestations can damage soybean crops. Soybean aphids overwinter in buckthorn, which is a common shrub in windbreaks throughout the northern United States, and fields near their location are often the first to be colonized by aphids in the spring, according to the University. State of South Dakota.
Six Boer goats from the University of Minnesota Crookston are used for the ongoing buckthorn control research project, which initially involved letting goats eat buckthorn in the River Valley Natural History Area Red near campus for two weeks in fall 2020. Goats were again entering the area in late spring and late summer 2021.
Research was conducted at different times to determine what time of year goat control of buckthorn is most important. In addition to determining how many buckthorn seeds are digested by goats and whether the ones that are not are viable after crossing the animals, the researchers are studying whether animals can control the small buckthorn plants by eating them.
Buckthorn leaves, like these in this photo, taken on October 28, 2021, stay green after other leaves have changed color or fallen off. Ann Bailey / Agweek
A year ago, after trials in which goats ate buckthorn plants and berries in the Red River Valley Natural History Area, researchers hand-fed each of the six goats, which were kept in the breeding barn of the UMC. The goats were individually fed 750 berries each containing three seeds. During the two-week feeding study, feces were collected every 12 hours and the seeds were extracted.
Only 25 of the 2,250 total seeds collected in the stool were viable in the 2020 manual feeding study, Simmons said.
UMC researchers repeated the project in 2021 during the last week of October and the first week of November.
Once all of the seeds have been collected from the goat droppings, researchers will plant them to see if they germinate. The last part of the project was not completed in 2020 because there were not enough seeds collected.
“This year, we’ve fine-tuned our fundraising process, and we’re getting more than last year,” said Lekatz.
There is not yet enough research data available to speculate on whether goats are an effective method of controlling buckthorn, she said.
However, the research itself is valuable for the undergraduates involved in the project and is an opportunity that most universities cannot offer, she said. Meanwhile, the research students, some of whom are majoring in agriculture and others in natural resources, are working together on a project similar to what they will likely do in their future careers.
“It seems like a perfect synergy,” Lekatz said.