Western Ohio True Value Hardware in Minster will be holding a “Soil Test Forum” on Thursday, April 6, at 6:30 p.m. A speaker from Brookside Laboratories will be there to talk about soil testing: what it is, why it’s done, how to collect the sample, how to read the results, and what actions to take based on the results. This class is free and will last about 30 minutes plus time for questions. If you’re interested in attending, please call the store at 419-628-3804 to reserve your seat!! The store is located at 4405 State Route 66 (about half-way between Minster and New Bremen).

As of the end of 2016, Palmer amaranth had been found in 18 Ohio counties. Not all of these “finds” represent problem infestations, and in some cases the potential for a few plants to become an established patch was remedied by timely removal and subsequent monitoring. There are, however, a number of fields where Palmer became well established and effective control has required extremely comprehensive herbicide programs combined with removal by hand.

This past growing season, three soybean fields were so densely infested with Palmer that they had to be mowed down in early August. At that point, the only recommendation we could make was mowing to prevent the production of massive amounts of additional seed in order to at least limit somewhat how bad future infestations were going to be. Apparently, these infestations had begun prior to last year and were ignored, allowing them to continue to increase to the point of disaster. This scenario is what occurred in the southern U.S. as Palmer spread and took over fields. Below are a few of the various paths of Palmer amaranth introduction into Ohio fields and the steps we can take to prevent infestations from becoming established.

1. So far, use of cottonseed feed products and subsequent spreading of manure from those livestock operations onto crop fields has been responsible for most of the infestations in Ohio. Palmer is widespread in cotton fields in the south, so the cotton harvest byproducts that are shipped to Ohio for use as feed have a high potential to contain Palmer seed. So, what do we do? Avoid use of these feed products. If continuing to use these feed products, find out whether the supplier has taken any steps to remove Palmer seed prior to shipping them here. It’s possible (but not guaranteed) that storing manure in pits for a period of time prior to spreading may reduce the seed viability.

2. Field to field spread by local equipment has occurred in a few areas of the state. This happens when (primarily) combines are used in Palmer-infested fields without complete cleanout afterward. And, yes, it’s impossible to get all Palmer seed out of a combine anyway! So, if hiring custom harvesters, ask whether the combine has previously been in fields infested with Palmer. Also, find out what the custom harvest operator’s philosophy is with regard to harvesting very weedy fields or those infested with Palmer: Does he avoid those fields? Are cleanout procedures used?

3. Purchasing used equipment that came from the south is known to be the source of several infestations in one area of the state: Even though a used combine was purchased from a local equipment dealer, it originated in Georgia. Know the full history of used equipment, especially combines. Avoid purchasing combines from Palmer-infested areas.

The above information was taken from an article by OSU Weed Scientist Mark Loux. More information on Palmer Amaranth (and other weeds!) can be found on the OSU weed management website – u.osu.edu/osuweeds.