News

Amaranth is getting more resistant to dicamba

A University of Wisconsin weed scientist says farmers are concerned about growing resistance to dicamba in the amaranth plant family. 

Scientist Rodrigo Werle tells brownfield he will be doing more research on waterhemp this year. “We have a lot of waterhemp samples we received from stakeholders that we have been working with. Yes, we’re doing a lot of work with those populations from all over the state.”

Werle says resistance issues are likely to be the big topic when researchers gather in Hawaii next week.

DTN reports that recent greenhouse experiments by Tennessee weed scientist Larry Steckel showed a lot of the two-inch tall Palmer amaranth did not die after a labeled rate of dicamba was applied and that University of Arkansas weed scientist Jason Norsworthy had similar results using Tennessee Palmer amaranth seed.  Those tests showed weeds started to recover four to five days after application and resumed active growth 14-to-21 days later.

About a year ago, Kansas State found resistance issues with dicamba and 2-4-D in several conservation tillage plots.

Wisconsin producers will be able to learn more about weed resistance issues during Werle’s Regional Waterhemp workshops in March.  They will be held at four locations:

• March 16: Bangor, WI
• March 17: Chippewa Falls, WI
• March 23: Appleton, WI
• March 24: Arlington, WI