Despite some warts, atrazine is still a heck of a corn herbicide, say crop consultants and weed scientists. And its low cost can be a special advantage to farmers during these tough economic times.
"Atrazine is easily the best corn herbicide available for most broadleaf weeds, based on its combination of effectiveness and reasonable price," says Ron O'Hanlon, president of Crop Quest Agronomic Services, Dodge City, KS.
"In most cases, our clients use atrazine in tankmixes, although they sometimes apply it alone," says O'Hanlon. "When it's used with other products, it seems to make those products more effective."
John Woerner, an independent crop consultant at Sullivan, IL, reports that atrazine is a key component of his clients' weed control programs.
"Many of our farmers are applying Bicep II Magnum or Harness Xtra - both of which contain atrazine - pre-emergence," says Woerner. "Some clients also add atrazine to those products in order to increase the performance and the residual control. With that extra atrazine we often don't need any postemergence treatment."
Woerner says the added atrazine also nails tall waterhemp. "Waterhemp has become a major problem for us and the atrazine, placed shallow, stays in the area where the waterhemp germinates," he explains.
He says Roundup has done a top job of controlling waterhemp in Roundup Ready (RR) soybeans. But if RR acreage drops, the atrazine in corn will become even more important in controlling waterhemp.
Atrazine also carries a lot of the load for independent crop consultant Greg Schneider, Hastings, NE, and his clients.
"We use it in one form or another on nearly 100% of our corn acreage," Schneider reports. "Mostly, it's part of a pre-emergence package. And where we need a postemergence treatment, there are cases where we've gone back to atrazine and oil as our treatment. It's part of our belt-tightening, and it works."
Also popular, Schneider notes, are various total post programs with Basis Gold or Lightning, plus atrazine. He says atrazine added to Liberty tends to heighten Liberty's performance.
But atrazine does have several soft spots. For one, it's a restricted-use product and is limited to 4 pints or 2.2 lbs/acre.
"The reduced rates now in effect for atrazine limit its ability to control certain weeds, especially grasses," says Purdue University weed scientist Tom Bauman. "Reduced rates also decrease residual control."
In addition, some weeds have become resistant to atrazine in certain areas. They include some pigweed species, velvetleaf, common lambsquarters and kochia.
Nevertheless, says Bauman, many newer herbicides have holes in their control spectrums, and atrazine often can fill those holes - at a reasonable cost.