By Clint Thompson
Cover crops remain a cost effective way of managing nematodes in Florida. That was a message touted by Johan Desaeger, assistant professor of entomology and nematology at the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Gulf Coast Research and Education Center, at the recent Florida Citrus Show in Fort Pierce, Florida.
Desaeger updated attendees about management for root-knot nematodes. The “most practical way” is to produce non-host cover crops to reduce populations.
“It’s not only about maximizing yields anymore, it’s about reducing inputs,” Desaeger said. “Growing a cover crop in the summer or offseason, the cover crop seed is cheap. You’ve just got to get it established and it has a lot of benefits.”
Benefits
Cover crops improve the soil quality and health in preparation for the upcoming growing season, while reducing nematode reproduction.
Sunn hemp is a good cover crop to use. It produces high amounts of biomass and is a poor host to root-knot nematodes and sting nematodes. It also contains alkaloids in its tissue. Its leaf and root residue have nematicidal activity, says Desaeger. He’s noticed more strawberry growers implanting cover crops during the offseason.
“I think there’s significant increase. When I look at strawberry fields in Hillsborough County in the summer, they’re full of sunn hemp,” he noted. “When I was here five or 10 years ago when I started, most of those fields were bare in the summer. You didn’t see a cover crop. Right now, you drive in Plant City in June, and you’ll see beautiful, yellowing, flowering sunn hemp all over the place.”
Nematodes have a wide host range and are most prevalent in Florida’s sandy soils. Root-knot nematodes enter the roots of plants, move through its cells until they reach sites where they grow, produce additional eggs and cause the roots to swell. This reduces the plant’s growth and any potential yield.
Desaeger also highlighted new nematicides that growers can start applying. One of those is Salibro® and is very effective against root-knot. Desaeger is pleased to see the newer chemicals be more adopted, especially since they are safer.