The benefits of cover crops continue to grow. Touted for conserving soil while filling forage needs, some plant varieties also have the potential to suppress soybean cyst nematode populations in no-till fields.
Ohio State University researchers in the Department of Horticulture and Crop Science have found that Italian ryegrass (also known as annual ryegrass), when planted as a fall cover crop, reduces soybean cyst nematode egg populations 30% to 50% in a single growing season.
Additionally, researchers discovered that Italian ryegrass reduces weed populations by as much as 50%, including purple deadnettle, which is a prolific overwintering host for soybean cyst nematode.
Kent Harrison, a weed ecologist with the university’s Ohio Agricultural Research and Development Center, says that the findings offer an additional tool for managing soybean cyst nematode, a small round worm that can cause significant yield reductions in soybeans. Soybean cyst nematode is the No. 2 soybean pest in Ohio, behind Phytophthora root rot.
“A rotation with nonhost crops still works as the best tool for managing soybean cyst nematode populations. We are not advocating growing cover crops as a substitute for annual crop rotations in pest management,” Harrison says. “We see this work as simply providing another tool for managing the pest with something that has multiple uses, benefits the soil, as well as acting as a short-term grazing crop. Italian ryegrass can do all of these.”
Harrison and his colleagues conducted the work over a 5-year period at OARDC’s Waterman Farm in Columbus, Ohio, inoculating a…