Ten acres is barely a blip on the radar for most of today’s farming operations, but it was enough to get the attention of Marshall and Mead Hardwick when they spotted pigweeds growing on those acres in 2017.
The brothers, who farm with their father, Jay, and mother, Mary Hardwick, on Somerset Plantation in Louisiana’s Tensas Parish, began attacking the Palmer amaranth almost as soon as they saw the weeds in their soybeans.
“We had two trouble spots that were collectively 10 acres, maybe, if that big,” says Mead Hardwick. “We have two fields with those spots that we’ve hoed; we’ve hand-pulled the weeds with trailers and crews. The areas with pigweeds weren’t getting bigger — but they definitely weren’t getting smaller.”
“And we’re starting to see small pockets here and there in different places that haven’t had issues with Palmer amaranth in years past,” says Marshall Hardwick. “You’re talking about maybe 10 to 15 plants in one area. But it’s slowly spreading across our farm despite our best effort. It’s a tough weed to control.”
Marshall Hardwick shows a Rogue Hoe that is especially designed for attacking Palmer amaranth.
Somerset Plantation, which has a farming history that predates the Civil War, has nearly 12,000 acres of certified farmland. Mary Hardwick’s family bought the land in the 1940s. Another 6,000 acres of managed timber provide habitat for wildlife, including a growing population of black bears.
Glyphosate-resistant Palmer amaranth has been relatively late arriving in Louisiana. Until recently, farmers in the state haven’t seen problems with the fast-growing weed that can produce 500,000 seeds per plant in a season.
“I think producers in this area have done a tremendous job of trying to keep the problem at bay,” says Mead, who’s been farming with Hardwick Planting Co. since 2014. “But there’s only so much you can do if you’re just reacting to the problem.”
Marshall, who joined the farm in 2013, had seen firsthand what glyphosate-resistant pigweeds could do when he worked as a summer intern for Monsanto in North Carolina in 2008. “They had hoe-hands chopping pigweeds and piling them on wagons that were being pulled through the fields by donkeys.”
Marshall and Mead tried that on the pigweed they spotted, attacking the weeds with special hoes called Rogue Hoes they purchased on Amazon.com. The weeds were hauled out of the fields on trailers. The transmission on one of their trucks was even damaged from pulling a trailer piled high with pigweeds.
“We noticed there were thousands of pigweeds coming up where we dumped the carcasses,” says Marshall. “We knew we had to do more to keep them from spreading to other parts of the farm.”
One of the first steps they took was to change row spacing. “In years past, we were probably 90 percent drilled beans on 7.5 inches,” he says. “We found that pigweeds were coming up with the soybeans, and sometimes they were below the canopy. After herbicide applications, they were still coming through.
“We decided to do a reversal of our thought process by planting back on 36-inch rows. That way, we would have better penetration of the herbicides and more direct contact on the pigweeds. We also pulled out an old hooded sprayer, so if things really got bad we could go through and spray Gramoxone under the hoods. We wanted to do the 36-inch row spacing so we could encourage some growth and go in with one or two applications and knock them out.”
They also decided to plant dicamba-tolerant Asgrow Roundup Ready 2 Xtend soybeans so they could use XtendiMax herbicide with VaporGrip Technology over the top of the soybeans, and because they liked the yield potential they had observed with the varieties.
They were careful to add a residual herbicide with the postemergence application, Marshall says.
“We put Zidua out with our Xtend application, and the XtendiMax really smoked what was out there,” says Mead. “We got a timely rain on the Zidua, which really helped keep the pigweeds from coming up to begin with. For the weeds that did come up, we made another application of XtendiMax because we were determined to beat them back.
“These are areas where we pulled trailer loads of pigweeds by hand last year,” says Mead. “This year, one of us would go by those two spots at least once a week, and I haven’t pulled more than three at a time out of those areas.”
The brothers had 4,700 acres of soybeans in 2018. About 1,400 acres were planted in an Xtend variety, Asgrow AG46X6 Brand, either to help with the control of Palmer amaranth or as a defense against the potential for drift.
Here’s the weed control program they used on their Asgrow Roundup Ready 2 Xtend soybeans in 2018:
Mead Hardwick points to a spot on a field map where Palmer amaranth was especially troublesome in 2017.
March 13: Made a burndown application of 32 ounces of Roundup, 1 ounce of Valor, and 2.8 ounces of 2,4-D.
April 30 and May 4: Planted Asgrow AG46X6 Brand soybeans on the two fields where they had hand-removed Palmer amaranth the previous year. Soybeans were planted ridge-till on 36-inch rows on 72-inch beds.
The planter was followed by a sprayer applying 32 ounces of Gramoxone, 32 ounces of a Loveland product called Intimidator, and 16 ounces of Herbimax, a crop oil. The Intimidator contains S-metolochlor or Dual, fomesafen or Reflex, and metribuzin or Sencor.
“This was supposed to be the foundation of what we thought would be a good clean start,” says Mead. “In some areas, it worked out really well, but, after we planted, May turned off really dry. So, most of these fields sat out there for two-and-a-half to three weeks before we had any really measurable rainfall. We don’t think we got the product activation we were hoping for. We did have some acres that received a rain right after planting, and those were some of our cleanest fields.”
May 23: Applied 22 ounces of XtendiMax, 2 ounces of Zidua, and 2 ounces of Compadre. The cost was $29 per acre, but only for the acres where the herbicide-resistant Palmer amaranth was targeted.
“With the good growing conditions, we’ve had a tighter canopy than we’ve had in a long time,” says Mead. “Even on our 36-inch soybeans the row middles are completely covered.”
They calculate the cost of the program in which they targeted the Palmer amaranth at $95 an acre. But they believe the cost was necessary to prevent the spread of the weed to other fields.
On the day they were interviewed, the brothers and their father took a visitor to one of the fields where Palmer amaranth was hauled away last year. They have kept coordinates in their phones for the area where pigweeds were rampant, so they could walk to it. No Palmer amaranth was visible.
What about 2019? “In 2018,” says Mead, “we had approximately 1,400 acres of Xtend varieties, centered around the trouble areas in the event we had to take a more widespread approach for control. Based on what we are seeing from both a Palmer control and yield potential, I believe we will likely stay in the 1,400 acre range for Xtend varieties, on the same acres as this year, with some possible expansion to combat a few other small problem areas.”