If you have a farmer buddy or relative who farms in the Mid-South, ask him how he likes Palmer Amaranth. A relative of pigweed, it's an extremely invasive weed that can take over quickly unless controlled, and that's not always easy. If you go visit him or her, make sure you don't bring the seed back with you.
OK, by now you're thinking, "Yeah, right, I'm going to bring a seed head back and throw it out in my field- Come on, what's the point?" The point is simply that activities you think little about can result in spreading seed from one weed species to another area, often much farther away than you might imagine. If conditions are favorable for the weed in the new area where the seeds eventually land and germinate, you've just introduced a new weed into the area. It may not be Palmer Amaranth, but it could be another species that simply adds to the headaches of planning an effective weed control program that will take out problem weeds without increasing chances that you might develop resistant weeds by the way you apply herbicides and rotate crops.
The Weed Science Society of America recently highlighted work by researchers at Montana State University that documented how weed seeds could stow away on various implements and vehicles, including four-wheelers. While Montana is not the Corn Belt, the same principles should apply. They even went too far as to determine how a vehicle needed to be washed after a rip off-road into fields to prevent spread of weed seeds, and if one type of washer was better than another. Their washing units performed about the same, but they determined that either one six-minute wash or two three minute washes were needed to make sure there wasn't weed seed left on the vehicle.
Other key findings include: several thousand more seeds per mile were transported in the fall than in the spring. That makes this information very critical right now. Second, more weed seeds were moved under moist conditions, since the seeds could stick more easily to parts of the vehicle.
Also, weed seeds could easily travel up to 160 miles before being dislodged. And if they dried in mud on the vehicle, they could be carried even farther than that. That's like picking up a weed seed on mud near Danville, Illinois, and carrying it to Dayton, Ohio.The take-home is simple- wash up vehicles that were in the fields this fall, especially four-wheelers, and especially if they were operating under damp conditions. You'll help yourself and your neighbors avoid spreading weed seeds to new locations.