Vinegar for weed control on cranberry farm
I'm submitting this question on behalf of one of our local cranberry growers. He's heard people mention using vinegar for weed control and would like to know more about how that is done and how effective it is.
Coos County Oregon
I'm assuming this is a question for a commercial cranberry grower. There is an OMRI approved (organically approved) vinegar herbicide for use on weeds surrounding crop plants (http://www.pharmsolutions.com/pdf/Weed-Pharm-Food-Use-Label-Comm-1gal.pdf). This product contains 20% acetic acid (vinegar) and, considering household vinegar is about 3%, it is a very caustic material requiring the proper spray equipment and protection when applying (see the associated MSDS label for the product). While we have had some success controlling small, recently germinated weeds using this produce in a certified organic blueberry farm, I would NOT recommend this product be used in cranberry. In blueberry and other row crops, the product can be spot applied to small germinated weeds with a shielded sprayer wand; this prevents any vinegar from contacting the blueberry shoots. Since this herbicide is non-selective, it will injury cranberry vines that are sprayed. Also, since there are no aisles in cranberry bogs or beds, I can think of no way to provide enough coverage of the product to kill the weed without damaging the cranberry vines. For this reason I would NOT recommend this type of herbicide be used.