Late planting challenges weed control
Ohio crop growers faced numerous challenges planting corn and soybeans this spring, and with the crop progressing through mid-July, they now face an interesting weed control scenario, as well.
"The late planting presents challenges and makes weed control easier at the same time," said Mark Loux, Ohio State Extension weed specialist. The unusual planting season resulted in an abnormal timeline for producers' weed control systems.
Because farmers couldn't get into fields as early as they would have liked to this spring, Loux said farmers saw significant weed pressure throughout June in both no-till and conventional tillage fields. In addition, some producers were not aggressive enough with their application of a burndown herbicide in no-till, and some weeds simply survived tillage this year.
Perhaps the biggest challenge to producers' weed control strategies boiled down to simple logistics.
"When we're planting that late, everyone gets jammed up and some missed applications," Loux said. "So, we have some fields that are really clean and some that are really messy."
In his travels around the state Loux said he was concerned that some producers had not yet sprayed a post-emergence herbicide. There is no point in waiting, he said, because establishing control of weeds as early as possible is critical in late planting situations.
Aside from the obvious challenges, a potentially shortened growing season does yield some positive impact on weed control.
"The good news in a late planting situation is you don't have as many weeks of weeds, and the crop grows faster," Loux said. "If you start weed-free and make that work, you can spray your post-emerge a little earlier and it makes control a little easier if you get the right start."
He continues to see glyphosate-resistant marestail as the key weed problem in the state, and 2011 may prove to be an enlightening year for some farmers because of the late planting.
While traditionally found in the southwestern portions of Ohio, Loux said resistant populations of marestail are now found throughout the state.
"We have a lot of marestail this season," he said. "We can't control it post-emergence very well. We have some problems in beans because farmers didn't pick the right combination of burndown herbicides, or they didn't want to spend enough money."
He also noted that in some cases, control efforts proved challenging because burndown application timing was much later than usual this season, and accordingly some products didn't work as well as in a typical year.