Crop farmers faced unusual problems in controlling weeds in their crop fields this year, said Kevin Bradley, weed scientist with University of Missouri Extension in Columbia, Mo.

“You can’t believe the phone calls,” Bradley said of a planting season marked by floods, cool temperatures and delayed planting of corn and soybeans. “Whether the problems are from the fact farmers couldn’t get in to spray until weeds were 2-feet tall or whether it was from herbicide-resistant strains of weeds, it’s hard to tell.”

Weeds will be among the problems to be discussed July 11 at an MU Weed and Pest Management Field Day at the Bradford Research and Extension Center near Columbia.

Wagon tours starting at 8:30 a.m. will continue until noon. A $10 registration fee includes lunch and handouts. Pre-registration is required.

The event formerly known as “MU Weed Day” now covers a variety of crop problems including disease, insects and weather, Bradley said.

MU specialists, including weed scientists, plant pathologists, entomologists and agronomists will discuss their research at the MU research farm as well as in plots across the state.

“We will discuss several years of research results on glyphosate-resistant weeds and give an update on emerging resistance problems,” Bradley said.

Researchers led by Reid Smeda, MU weed scientist, will tell of studies on how herbicide resistance develops and spreads in weeds. When farmers use the same herbicide year after year to control weeds in a field, some weeds can develop tolerance or resistance to herbicides.

The weed scientists are studying the role of pollen in spreading the genetic resistance through seed development.

Smeda will also discuss using digital technology in scouting weeds in crop fields. He believes cameras mounted in fields can be connected to computers to help identify emerging weed problems.

Plots with insecticide seed treatments to protect both corn and soybeans will be shown. There will be an update on emerging insect problems, said Wayne Bailey, MU Extension entomologist.

Laura Sweets, MU plant pathologist, will show plots of fungicide seed treatments and foliar fungicide treatments for corn and soybeans.

Bradford Research and Extension Center plots contain hundreds of comparisons of both recommended and experimental herbicides, Bradley said. A plot book, showing locations of the trials will be included in the registration packet.

Visitors are encouraged to stay in the afternoon to view the plots to see how their weed control practices compare with newer methods, Bradley said.

Certified crop advisers (CCAs) can sign up for two continuing education units. Individuals who are not CCAs are encouraged to attend as well, Bradley said.

To register, or request information, contact Thresa Chism at chismt@missouri.eduor call 573-884-7945.

Bradford Research and Extension Center is part of the MU Agricultural Experiment Station. To reach the Bradford Center, take U.S. Highway 63 to the AC/Grindstone exit. Travel east about five miles on New Haven Road, then south for about one mile on Rangeline Road.