Proper weed management important
By Jennifer Carrico
Proper weed management is a key component in having good crop yields, according to Bob Hartzler, Iowa State University Extension weed specialist.
"When it comes to weed management, we must first understand weed biology and use a diverse approach to managing the seed bank," he said. "This includes preventing seed movement between fields, managing weed seed at harvest and managing weeds in field borders."
Weeds were managed in the 1980s with glyphosate, which farmers began to rely upon greatly. He said this reliance actually let to problems. When weeds aren't properly killed the seeds can spread at a very high number, very quickly.
Hartzler suggested planting new crops into weed-free fields. "This year it was difficult to follow all the perfect protocol because of the weather," he said. "I also suggest planting weed-free crop seeds, which can sometimes be a problem with oats and other cover crops since it's a lot harder to sort that seed."
It is important to scout fields routinely for weed problems and if one is found, to act quickly to manage the problem.
"Use multiple herbicides and sites of action that are effective against the problem weeds," he said. "These products should always be used at the proper levels if you expect them to work."
Herbicide should be applied at the rate recommended on the label for the particular weed size.
Hartzler said the use of mechanical and biological tactics are another good way to manage weeds. Cultivation can be used to stay ahead of the weed problems.
"While we are trying to kill the weeds that are showing up, we also have many seed predators who are helping with those we don't get killed," he said. "Seed predators eat 20 to 90 percent of the weed seed produced. These predators include many different insects and field mice."
Hartzler said no matter what mode of action is used in controlling weeds, it is very important to pay attention to detail, enhance competitiveness and manage each field individually.
Jennifer Carrico can be reached by phone at 515-833-2120, or by email at firstname.lastname@example.org.