URBANA, Ill. — There was certainly no shortage of weeds to study at the University of Illinois Field Day June 28 in east central Illinois. The abundance of weeds here is similar to what farmers are finding across the state.
“There’s great weed control where there is standing water,” joked Charlie Mitsdarfer, but most other areas this year had challenges with weeds.
It has been an odd year. Near the research farm, some soybeans were planted in February and some corn planted in June.
Weather conditions and timing played a big role on the development of these crops and their competition with weeds, said Mitsdarfer, a University of Illinois weed science research specialist.
Some pre-emergence programs didn’t get activated because it didn’t rain after they were applied.
Other farmers were unable to follow their pre-emergence plans because there was too much rain, he said.
Pre-emergence herbicides are critical with a year like this one and are more effective when layered in a combination with a post herbicide.
With low commodity prices, farmers are looking at cutting costs, the weed scientist acknowledged. Some have chosen to reduce herbicide rates, but scrimping on applications can be expensive too, he said.
Cristin Weber, a Syngenta research and development scientist, said trying to stretch the herbicide dollar can backfire. But the windy weather also interfered with plans for spraying.
Mitsdarfer and Weber said waterhemp is a big threat. Marestail is a challenge this year because it got so tall before it could be treated. And Palmer amaranth is making its way through Illinois.
In the test plots, velvetleaf, burs, thistles and a variety of other weeds also survived some of the treatments.
Attendees including local farmers, landowners, crop advisors, company representatives, students and visitors from Argentina talked about the variety of weed challenges this year and attempts to handle them.
“It’s been a rough year all around. There are lots of issues,” said Kevin Johnson, a Dow AgroSciences field scientist based in Danville, Ill.
Too much rain at some points kept farmers from applying herbicides when they wanted to this season. And, later applied herbicides didn’t get enough rain to activate, he said, reinforcing Mitsdarfer’s observations.
For growers across the state, the biggest challenge this year is waterhemp, Johnson said.
“We have to rely on residuals and new post applications such as Enlist,” Johnson said.
This season reinforced the fact that “every year is unique” Johnson said it’s wise to have a long-term weed protection system rather than playing a “short-term” game by trying to cut costs this year.
Timing is especially important this year. Waterhemp should be controlled before it is 4 inches tall. If it gets to be 6 to 8 inches, it is tough to control, he said.
Russ Higgins, crop scientist and Extension educator, said there are different weeds in this part of Illinois compared to northern Illinois where he is based. Giant ragweed is a big problem there.
He joked that they don’t have a problem with “wimpy morning glory,” which was present on the Champaign area plots.