Headlands, or so-called turn rows, typically deliver lower crop yields. It’s why those areas often get less management attention and fewer inputs, including herbicide applications.
That’s understandable, but broadleaf weeds and grasses often find refuge and thrive in those areas, says Matthew Inman, BASF technical marketing manager for herbicides.
When left uncontrolled, weeds are adept at using turn rows as launching sites to root, grow, produce seed and then expand into broader crop acres in subsequent years.
“There’s a lot of truth to the saying that ‘one year’s seeding, makes seven years weeding,’” Inman says. “While it can take several years to minimize a weed seedbank in soils, it takes only one year of replenishment to have to start all over again to deplete it.”
MANAGE LIKE BROAD ACRES
Inman’s recommendation is to address weeds in turn rows with the same thoughtful thoroughness you use on broad-base crop acres.
“We have to manage those areas, along with ditches, tree lines and field borders, the same as we would in broad crop acres to prevent weeds from spreading,” he says. “Use a variety of tactics, including various modes and sites-of-action herbicides along with crop rotation, tillage and hand weeding, if necessary.”
Be aware what constitutes a turn row is sometimes vague as it relates to herbicide applications, says Jason Bond, Mississippi State University Extension weed scientist.
“Unfortunately, not all the concepts related to herbicide applications in such areas are defined, so caution should be exercised before herbicides are applied to turn rows and/or ditch banks,” he says. “When deciding to spray a turn row, consult the herbicide label and manufacturer to determine if the application is legal.”
In some cases, you might have to resort to pulling weeds by hand and using tillage or mowing to prevent weeds from flourishing.
None of those options are ideal, but they can be a yield booster for future crops by removing seeds from soil seed banks, explains Dave Nicolai, Extension educator at the University of Minnesota, and Jared Goplen, a former university Extension educator now an agronomy manager with Wyffels Hybrids.
THE GOOD NEWS
Goplen and Nicolai say if waterhemp is prevented from “going to seed” for four years, over 99% of its seed bank can be degraded. A giant ragweed seedbank can be depleted even faster, with over 95% degraded in just two years.
