The Secret to Slowing Down Pigweed
Pigweed is thought to have acquired its name because it was once fed to pigs. But farmers have come to find its name appropriate for another reason – it gobbles up sunlight, water, and nutrients intended for their crops.
The cost of this resource grab can be severe. The University of Illinois has cited yield losses as high as 78% in soybeans and 91% in corn, and farther south, cotton farmers are all too familiar with resorting to hand-hoe crews to physically chop and pull pigweeds out of their fields.
There may be no stopping pigweeds, but farmers need to do all they can to slow it down. It all boils down to a simple three-step process.
- Know what to look for. Individual pigweed species respond uniquely to various herbicides. Iowa State University has an extensive guide to help farmers distinguish between five significant members of the pigweed family, including Powell amaranth, Palmer amaranth, smooth pigweed, redroot pigweed and common waterhemp.
- Be a diligent scout. Start early and keep it up. Get into the field and look for signs of weeds as early as 10 or 12 days after planting. After that, scout for weeds periodically every four to six weeks. Be sure to sample enough areas to get an accurate count of the weed species in each field. More farmers are deploying drones to efficiently scout and document weed problems across their entire operation.
- Adopt a zero-tolerance policy. Because pigweed is notorious for its resistance to several herbicides, it’s important to use multiple modes of action and follow full, labeled rates. For best results, start with a pre-emergent application, then follow up with a post-emergent herbicide when plants are small. Other best practices include planting cover crops and rotating cash crops.
Photo Credit: © 2012 AgStock Images / Bill Barksdale