For the first time, the maximum labeled rate of cyanazine will fall to 3 pounds of active ingredient per acre in 1998. As a result of an agreement between the Environmental Protection Agency and DuPont, products like Bladex, Extrazine II, Cy-Pro and Cy-Pro AT that contain this ingredient are being phased out.
Next year, the maximum labeled rate of cyanazine will drop to only 1 pound of active ingredient per acre. While cyanazine won’t be sold starting in 2000, customers have until 2002 to use up existing supplies.
University weed scientists say there are comparably priced alternatives, including some that offer superior control against pigweed species like waterhemp.
While no-tillers can use Extrazine for burndown in no-till corn this year, it’s not too soon to be considering alternatives. “One alternative burndown option is Gramoxone Extra,” says George Kapusta, weed scientist at Southern Illinois University and a speaker at the recent sixth annual National No-Tillage Conference. “With growers planting and applying crop production products earlier in the spring, they want to see weed control before the corn comes up.”
Jim Martin, weed scientist at the University of Kentucky, agrees that Gramoxone works well if you need quick burndown or if you’re spraying in the spring when it’s cooler. Don Null, agronomist at the University of Missouri, says Gramoxone tankmixes easily with residual herbicides without antagonism concerns.
Other options for burndown weed control are Touchdown and Roundup Ultra. Both are effective in controlling tough perennials.
Still another burndown option…