The dreaded 'M' word - Mechanical weed control

May 19, 2016 1:08 PM
Blog Post

While driving to a field plot in Webster County earlier this week I saw a land roller being used in a field. My first thought: "If we have time to roll fields, why is there such resistance to the suggestion of mechanical weed control?"


Most farmers of my age have memories of long days on the tractor with a cultivator, a task that required undivided attention to avoid epidemics of cultivator blight. As more effective herbicides were introduced in the mid-1980’s, the widespread use of cultivators became a thing of the past. With the rapid spread of herbicide resistant weeds, is it time to reconsider our aversion to this practice?


Technology has not revolutionized mechanical weed control as happened with chemical weed control over the past 30 years; however, cultivation doesn’t need to be the dreaded practice of the past. Advancement in mechanical weed control for row crops comes in the form of automatic steering technology rather than improved cultivator design. Research has shown that automatic steering allows cultivators to be operated at twice the speed compared to manual steering, while maintaining the same levels of weed control and crop yield. Nearly as important is the elimination of the fatigue associated with the practice.


While I’m not suggesting a return to the days where nearly all acres received at least one pass of a cultivator, the rapid rise of resistant weeds warrants a reevaluation of this management tool. Fields or portion of fields that have persistent weed problems can be targeted for cultivation. The use of multiple effective herbicide groups can help manage herbicide resistance, but alternative tactics are essential. Mechanical weed control is one of the simplest alternative tactics to place into the current production system.



Alternative selection pressures are needed to stay ahead of weeds.

Category: 
Author: 

Bob Hartzler Professor of Agronomy

Dr. Bob Hartzler is a professor of agronomy and an extension weed specialist. He conducts research on weed biology and how it impacts the efficacy of weed management programs in corn and soybean. Dr. Hartzler also teaches undergraduate classes in weed science and weed identificatio...