Sources of Palmer Amaranth in the Midwest

It is a really bad year for Waterhemp in our area.  Palmer Amaranth is closely related, and vigilance is needed to keep it under control.  Beware of sources that may bring seeds to your area.  I have seen Palmer Amaranth in Bond County that came in Cottonseed dairy feed products.  The seed runs through the cow and you spread it on your fields.  Another source may be CRP seed.  This article out of Ohio from No-Till Farmer suggests screening CRP mixes to get rid of Palmer Amaranth. I have heard reports of dirty seed out of Iowa as well.  Also, be sure clean harvest equipment when moving from infested fields.  University of Arkansas is suggesting the only way to control Palmer Amaranth is total eradication.