Farm Talk

January 29, 2013

Local growers get latest on new herbicides

by Kenny Ragland

Parsons, Kansas — Controlling herbicide resistant weeds was the hot topic during the Andrew County Ag. Update conference on Thursday, Jan. 17 in the Clasbey Center in Savannah, Mo.

Northwest Regional Agronomist Wayne Flanary went over the latest spray products available for growers to handle water hemp, Palmer Amaranth and the whole family of Roundup resistant pigweeds.

“These weeds are becoming resistant to products with three of the more popular modes of action now,” said Flanary. “We are starting to recommend pre-emergent products to change the modes of action even further, and stop the weed before it gets a start.”

The newest product to be labeled for this type of use is Zidua, marketed by the BASF Company.

“There are other companies that will have this same chemical,” Flanary said. “The trade names are Fierce and Anthem. They just don’t have their EPA label approved yet.”

The active ingredient in the new products is pyroxasulfone. It has a root and shoot inhibitor type of mode of action. Different from other root and shoot inhibitors, the chemical attacks fatty acid synthesis in the weed.

“This product works similar to Lasso,” Flanary said. “It is especially effective on small seeded broadleaf weeds like the pigweed family.”

Zidua is currently labeled for corn. Fierce and Anthem are awaiting their label approval. When that happens, they can also be used in soybeans and as a pre-plant product for wheat.

“This is good news for growers wanting to rotate to wheat,” Flanary said. “Carryover is a bigger problem now with the drought.”

Flanary went over adjuvants briefly.

“Glyphosate (Round-Up) doesn’t need crop oil to be effective,” he said. “Just use ammonium sulfate and you will improve the uptake all you need to.”

Increasing the amount of water for post-emergent spray will help, as area growers confirmed.

“We used 18 gallons of water on some of our soybeans,” said Travis Smock. “We compared it to a spot with only 10 gallons of water and you could tell the difference in emerged weed control.”

Scouting for insect damage was something the agronomist stressed.

“Podworms, cucumber beetles and stink bugs can sneak up on you,” Flanary said. “If you see damage on the leaves, they have already worked over the pods.”

Over 20 growers completed the Private Pesticide Applicator process. The nominal fee was $12 and the class was completed in two hours.

For more information on the latest in weed control, growers can go online to

Agronomist Wayne Flanary can be contacted at or by phone at 660-446-3724. £