Glufosinate (Rely 280, Surmise, and others) has been cleared for use in stone fruit. This has been in the works for some time and stone fruits are listed on the labels. I have pasted a link to the Rely 280 SL label below. This a very good non-selective POST herbicide option for stone fruit. It is very effective on horseweed and has some advantages over paraquat.
Please share this information with your growers and if you have any questions let me know.