Three Tips to Master Proactive Weed Control
When just a handful of prolific, pervasive weeds such as Palmer amaranth and waterhemp are able to pump millions of seeds into a field, experts agree: a zero-tolerance approach to weed management is the new standard.
This stance requires the adoption of a proactive weed-control mindset. Three strategies in particular will put farmers on the right path.
- Start with a clean field. When fields are full of weeds at planting, it’s a losing proposition. Those unwelcome guests are free to immediately steal sunlight, water and nutrients, which immediately puts good stand establishment at risk. To make matters worse, if weeds are damaged by farm equipment during planting, they become more difficult to control with later herbicide applications.
- Use a pre-emergence herbicide. This practice has become essential, asserts Daniel Stephenson, a weed scientist with Louisiana State University’s AgCenter.
“It is still the bedrock we need to plant our corn weed-control program on,” he says.
Pre-emergence herbicides can be applied to clean ground or tank-mixed with a nonselective burndown herbicide. Farmers will then need to scout fields closely after crop emergence because certain weed species such as pigweed and waterhemp become tougher to control if they grow much taller than 2 to 3 inches.
- Assume resistant weeds are already there. The best way to combat resistant weeds is to use a proactive strategy of both pre-plant and pre-emergence residual herbicides containing effective, overlapping modes of action. Don’t make a decision before considering these factors:
- Labeled length of residual
- Application timing
- Weed-control spectrum
- Resistance management
- Crop rotation flexibility
According to many agronomists, in today’s environment, there’s no such thing as an economic threshold for weeds. Zero tolerance for resistant seed in the soil bank should be the goal.
Photo Credit: ©2013 AgStock Images / Thomas Dodge