BISMARCK, N.D. - Tom Peters worked for 25 years in biotechnology and now is the Extension sugar beet agronomist and weed control specialist for North Dakota State University and the University of Minnesota. He can boil his weed control presentation down into two points.
"The first one is, technology by itself isn't going to solve our problems with weeds," he said. "The second thing is, weed management is a learning experience."
Peters gave his talk, "Hogtied by Pigweed," during Wheat U on Jan. 17 in Bismarck. Wheat U was sponsored by Agweek, High Plains Journal and BASF to give a specialized education in wheat management.
Pigweed, he said early in his presentation, was just an example. The same approaches can benefit any weed problem.
Peters said that when he was in college and early in his career, herbicides continued to improve and seemed like the answers to all the questions. That has changed as weeds have built resistance to different products.
Instead, fighting weeds needs a multifaceted approach, he said. Using different types of herbicides, using mechanical means like pulling by hand, mowing or tillage, and using more crops in a rotation all can help, he said.
The crop rotation component is important to change up conditions that influence weed survival, like crop planting dates, row spacing, fertilizing, tillage, pesticides and residue. Three to four crops would be better than the two-crop rotation - corn and soybeans - popular in parts of the region.
"The more crops you can grow on the farm the better. And I'm saying this just from the standpoint of weed management," Peters said. "We're making it way too easy with only two crops."
Learning from the experiences of the past or from experiences of produces in other parts of the country also are important, Peters said. He explained how he and other Extension officials looked to other states, like Nebraska, as they became worried about Palmer amaranth. He credits an educational campaign for the quick identification of the state's first case in McIntosh County.
The weed now has been identified in five places in North Dakota, and the weed moved through different means in each case, Peters said. The McIntosh County weed appears to have been sown through migratory birds. A case in Dickey County came from a used combine purchased from out of state. A Foster County case was carried through custom combining. A Benson County case came from a railroad car cleanout. A Richland County case came through alternative sources of cattle feed.
"I want to argue that weeds are just as mobile as insects," Peters said. "And they move in different ways."