A plant valued as a cheery native wildflower often seen along Arkansas byways has a kissing cousin, tickseed coreopsis, which is a problem weed for some Jefferson County, Ark., rice producers.
“The past two days, I have had samples brought in of a ‘new weed’ in a rice field ,” said Don Plunkett, Jefferson County Extension staff chair for the University of Arkansas Division of Agriculture. “Turns out that it is probably tickseed or plains coreopsis — a hard weed to kill in fields.”
Plunkett said Bob Scott, an Arkansas Extension weed scientist, has received a flurry of calls about stray coreopsis.
“Although this weed will not survive in the flood, it is difficult to control and can hinder efforts to get a stand established,” Scott said.
“Glyphosate products will not work and paraquat only burns the weed back temporarily,” Plunkett said. “And when given the recommendation to use a shovel and dig them up, growers frown.”
Thistles are also raising their spiky violet heads in fields.
Plunkett has received calls and e-mails from people who are seeing thistles pop up in pastures, ditches and pastures where they hadn’t seen them last year.
“‘Too late to kill’ is the response I have to give at this time,” he said. “So many of these weeds have bloomed and are maturing. Herbicides will have a difficult time killing them.”
Plus, the thistles are at the seed-dispersal stage. Thistles spend one year growing, then the next making seed. This year is a seed year for many.
A shovel is an effective tool, but tedious, Plunkett said, adding that constant mowing can help keep the seed heads from forming.
Plunkett recommended Extension publication MP44, “Recommended Chemicals for Weed and Brush Control,” available online at www.uaex.edu , or it may be ordered online at the same address.