A "gorilla" of a barnyardgrass and a "tough critter" nematode are two of the problems being tackled by LSU AgCenter researchers as reported at the June 24, 2008, field day at the
Northeast Research Station in St. Joseph.
Daniel Stephenson, LSU AgCenter weed scientist, told farmers that barnyardgrass "is setting up shop" in the neighboring area of the station, and glyphosate, the chief herbicide used to control it, may no longer be working.
"We need to switch modes of action for control of these weeds," he said. "We need to get residual herbicides out there to control these weeds."
He told farmers if their weeds are not dying, they need to contact someone in the AgCenter to help determine if the problem is with application procedure or resistance.
Charles Overstreet, LSU AgCenter extension nematologist, said the reniform nematode is becoming more widespread. This "tough critter" can survive in soil a long time and without a host.
Overstreet suggested treating zones or areas in a field that have extremely high levels of reniform nematodes with one nematicide (a fumigant) and treat lightly infested areas with another (seed treatment or at-planting nematicide).
"Nationwide, we lose $100 million a year to reniform nematode. This is a not a lightweight issue," he said. "It’s not likely that you will ever eliminate it. All you can do is manage it. Don’t let it be a big factor hurting you on yield."
Jeff Davis, LSU AgCenter entomologist, called the red-banded stink bug the new pest of soybeans.
"It is the predominate species out there," he said, adding that Arkansas and Texas are also seeing more of the pest.
Davis said the red-banded stink bug is more tolerant of pesticides used to control stink bugs. Studies are monitoring the stink bug complex at six AgCenter sites, including St. Joseph.
Davis said scientists will be able to tell growers the appropriate applications in the future so they will only have to spray that section of the field affected by the bug and not kill beneficial insects.
Mary Ann Van Osdell
(This article was published in the summer 2008 issue of Louisiana Agriculture.)
