0
Home
News
Directory
E-newsletter
Magazine
Events
Data
AgReport
Subscribe
Scientist asks growers to watch for herbicide resistance
Jan. 11, 2016
A University of Idaho Extension weed scientist is asking growers and agronomists to save weed seeds for research purposes in the coming season if they encounter redroot pigweed or common lamb’s quarters that withstand herbicide treatments.
Pam Hutchinson suspects metribuzin herbicide resistance may be on the rise within Idaho’s populations of redroot pigweed and lamb’s quarters.
In 2005, Hutchinson received her first report of metribuzin resistance suspected in redroot pigweed from a grower in Shelley, who acknowledged he’d used the chemical every other year on potatoes since the 1970s.
“He said metribuzin was no longer controlling redroot pigweed, but it had controlled it really well in the past,” Hutchinson said, adding that he switched to other herbicides.
More recently, growers throughout Southern Idaho’s potato production area have also reported evidence of metribuzin-resistant lamb’s quarters.
Hutchinson hopes to plant seeds from weeds that survive metribuzin applications for testing in a greenhouse to confirm that resistance is occurring.
Metribuzin, which inhibits photosynthesis in weeds, was one of the first herbicides approved for potatoes. It can be used before potato plants emerge, but is the only herbicide labeled for post-emergence lamb’s quarters control in spuds.
Hutchinson said a rise in lamb’s quarters could also be the result of a weed shift, due to the fact that popular herbicides, such as glyphosate, control hairy nightshade but are less effective on lamb’s quarters.
“We’re using products that target the worst weeds but miss lamb’s quarters,” Hutchinson said, adding that there hasn’t been a new herbicide chemistry released in 20 years.
Hutchinson did the research to justify a special-needs label in Idaho and Washington potatoes for Linex, a pre-emergence herbicide with strong lamb’s quarters control.
Hutchinson’s research application to survey Idaho for metribuzin-resistant weeds was denied, but the Northwest Potato Research Consortium has requested a full proposal on a collaborative project involving the four Northwest weed scientists regarding trials into blending herbicides to target specific weeds and delay or prevent resistance.
“If we don’t take care of (metribuzin) then we’re in trouble,” Hutchinson said. “There are only a few other herbicides that in potatoes will control common lamb’s quarters.”
She advises growers to keep a history of herbicides use and weed history in fields to help evaluate chemicals that may have worked in the past but appear to be losing their effectiveness.
Source: Capital Press
More from AgroNews
Change
Hot TopicSubscribe
| Subscribe Email: | * | |
| Name: | ||
| Mobile Number: | ||
Comment
0/1200
NEWSLETTER