Tackling RRV Weeds In 2013: Adapting To Change


Gary Johnson Unity Seed Company of Casselton, N.D., spot-sprays common ragweed in a field of conventional, food-grade soybeans just south of Amenia, N.D., on July 12.

Gary Johnson works in the farming end of the Unity Seed Inc. operations at Casselton, N.D. Unity Seed Co. at Casselton, N.D. Unity Seed does food-grade exports to Japan and seed sales. Agweek stopped to talk to him for a CropStop on July 12, after attending a separate press field tour for the Monsanto Xtend system. (See Agweek, July 22).

When Agweek happened by, Johnson was spraying ragweed in a low spot in a conventional, food-grade soybean field, just south of Amenia There were some test plots in the field a few years ago, and weeds require some spot spraying, he explains.

This has been a relatively good year for weed control in the area, Johnson says. He says a new chemical from Valent U.S.A. Corp. called “Fierce.” “That’s a pre-emerge chemical and that’s done an excellent job for us on this food grade (soybean crop),” Johnson says. “It’s just done wonders. We’ve got pretty clean fields.”

There was lots of rain in the area this spring. Fierce “needs the rain” to be active, Johnson says. “When you spray it on you need a minimum of a quarter-inch to get it activated and every time it rains it reactivates again, and you get germinating seeds.”

Three years ago herbicide resistance for common ragweed in the Casselton area, Johnson says, and the lambsquarters weed has become “very resistant” in the area, he adds. “We don’t have a large problem because we have rotation (crops). The guys that grow beans, and beans … and beans, without rotation, have a bigger problems. You can kill it with 2-4,D in your wheat but it’s getting tougher, and buckwheat, while not resistant, is really getting tough to kill with (glyphosate).”

In mid-July, crops in the Casselton area were behind but doing surprisingly well considering the slow start. Corn would be tasseling by Aug. 1, Johnson figured. “That’s generally what you want on corn is to have it tasseling by then, and then hopefully I think (about) Sept. 20 is our frost date, so we want it black-layered by then,” he says, referring to the physical black layer located at the base a corn kernel at physiological maturity.

The soybeans were short but could come on if they get more rain, he says. Johnson says he personally doesn’t mind 85-degree temperatures, but if it gets above that it doesn’t help crops, particularly corn. “It just cooks stuff quicker,” Johnson says. When night-time temperatures get into the 70s, or 60s, it provides some growing degree units. “As long as it doesn’t freeze, that’s the main thing,” he says.

Agweek correspondents have been traveling into Montana, central and southeastern South Dakota, and into central Minnesota. Watch for CropStop features in July 29 and Aug. 5 issues. I always find it fascinating to meet farmers and hear what’s on their minds. Feel free to send me your thoughts on the ag scene at my e-mail, mpates@agweek.com