• Without proper control, Palmer amaranth can emerge following crop harvest and produce seed in the fall months, resulting in an increase of the seed bank for the next growing season.
The months between this year’s harvest and next spring’s planting are prime time for weeds to take over fields.
In the South, that can mean another opportunity for glyphosate-resistant Palmer amaranth, or Palmer pigweed, to threaten future yields and cause unnecessary, potentially costly headaches.
“The thing that makes pigweed so problematic is it’s such a prolific seed producer,” said weed scientist Bob Scott, of the University of Arkansas. “A pigweed can come up and produce seed in as short as a couple of weeks.”
Without proper control, Palmer amaranth can emerge following crop harvest and produce seed in the fall months, resulting in an increase of the seed bank for the next growing season.
Farmers aiming to control pigweed before it emerges and spreads significant amounts of seed — as well as control other escaped weeds — should consider implementing a post-harvest burndown and residual program.
“No farmer wants to start the next growing season with a seed bank full of pigweed,” said Dan Westberg, technical market manager, BASF. “With a fall burndown and residual program, farmers can reduce the seed bank of resistant weeds and have a fighting chance the following season.”
With glyphosate-resistant Palmer amaranth throughout the South, weed management experts are more adamant than ever that farmers use a complete weed management program that includes multiple herbicide sites of action.
“Regardless of what they’ve experienced this year, with a fall burndown and residual program, growers will be able to start fresh in the spring,” said Westberg. “Additionally, a fall program is an opportunity to incorporate additional sites of action to the field, making it an important tool in the ongoing challenge of managing resistant weeds.”
A fall burndown and residual program is a critical strategy in reducing seed banks.
“You have to manage weeds not just 30 days before you plant, but even 30 days after you’ve harvested,” said weed scientist Larry Steckel, of the University of Tennessee.
One option for a fall program is a tool like Sharpen herbicide, which is powered by Kixor herbicide technology. It provides fast and effective results, and it has been shown to work three to five times faster than glyphosate and 2,4-D.
When tank-mixed with a residual herbicide, Sharpen herbicide can help provide extended control of weeds, which will be especially important this fall, as harvests are happening earlier than usual.
“If growers use a herbicide that offers a good burndown, they can accomplish two things at once,” said Westberg. “First, they clear out existing weeds that have the potential to spread seeds. Second, if they tank-mix with a good residual, it helps suppress any seeds in the soil that have the potential to pop up and cause problems prior to the first killing frost.”
For more information on herbicide best practices, visit http://on.basf.com/weedbp.