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Hay CRP Sprayed With Milestone (06/22/17)

Question: I have a producer that wants to spray CRP with Milestone.

Hay CRP Sprayed With Milestone

Question: I have a producer that wants to spray CRP with Milestone. This field may be hayed this year or next depending on the contract specifications. The weed control guide states no haying or grazing restrictions. On the label it talks about 18 month restrictions for haying. In another place it talks about 3 days. In another spot it talks about no restrictions. Would there be a problem with haying this field down the road and having a problem with residues in the manure from the hay. I know that Milestone has a pretty good residual and that we need to be aware if a CRP field will be farmed in the next few years. Would that residual be an issue for hay down the road that may be fed at the farm and manure spread out onto cropland.

Answer: There are no grazing or haying restrictions with Milestone, animals can eat the grass or hay. However, the problem comes with the residue. There is a 3 day waiting period before you can move livestock that have fed on treated forage (green grass or hay) to areas with sensitive plants.              

You can cut the hay any time after treatment. However, Milestone (aminopyralid) like Transline (clopyralid) does not break down very much when tied up in grass residue. That is why the label says that the hay must be used on the farm/ranch where it originated for up to 18 months after harvest. So, if you feed animals with this hay up to 18 months after treatment, the manure could contain aminopyralid and you would need to wait 3 days before moving them to areas with sensitive plants.

It gets a little confusing, so I would say if someone applies Milestone and then hays, you need to assume the hay has residual herbicide in it. No problem to the animals, but do not move them or the manure to a sensitive crop area, like feeding on alfalfa in the fall or spreading manure on a field that will be seeded to soybeans. This drawing from the label helps explain in an easier to understand way.


Rod Lym

NDSU Weed Science, Noxious and Invasive Weeds

This site is supported in part by the Crop Protection and Pest Management Program [grant no. 2017-70006-27144/accession 1013592] from the USDA National Institute of Food and Agriculture. Any opinions, findings, conclusions, or recommendations expressed are those of the website author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.

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