Glufosinate, recently sold under the trade name Rely 280, has been recommended for use as a postemergence herbicide in grapes for many years, but has been NOT RECOMMENDED for use in peaches or apples. Additional glufosinate products are being introduced into the marketplace with labels for grapes, stone fruits, pome fruits, blueberries, and other fruit crops. Trade names for the new glufosinate products include Cheetah and others.
Rely 280 (glufosinate) was never evaluated in blueberries, and has not been recommended in New Jersey due to the potential for injury to well established trees. Glufosinate absorbed through the mature brown bark of the lower trunks of the trees resulted in the death of the cambium layer under the bark where the herbicide contacted the bark. Applications were made in late spring using rates and application techniques typical of orchard herbicide application. No injury was observed the year of application. The injury was observed and the trunks were photographed the following year. Other studies did not always cause trunk injury, so injury should not be anticipated every time glufosinate is used, however, the injury can be devastating. Only one side of the trees in the pictures was treated, so the trees in the pictures were not girdled, but the potential to girdle tree exists. Roundup, 2,4-D, and Stinger were included in these studies and no injury was observed following the use of any of these products. Only glufosinate injured the trees through mature brown bark.
Do not confuse glyphosate (Roundup and other trade names) with glufosinate (Rely 280 and other trade names). Although the “common chemical” names sound similar, the products are not similar. Modes of action are different and injury symptoms are different. Glufosinate products, Rely 280 and other trade names has been and will continue to be recommended for use in established grapes, but have NOT and WILL NOT be recommended for use in stone fruit or pome fruit crops.