Foxtail barley (Hordeum jubatum) control with propoxycarbazone-sodium and fluazifop-p-butyl in three Alaska Native grass species

Abstract

Foxtail barley is one of the most detrimental weeds for the Alaska native grass seed industry. Its control is essential for improving seed production and stand longevity so producers can meet statewide seed demands. The objective of this study was to determine suitable chemical controls of foxtail barley for three different native grass species: 'Nortran' tufted hairgrass (Deschampsia caespitosa L.), 'Gruening' alpine bluegrass (Poa alpina L.), and 'Wainwright' slender wheatgrass (Elymus trachycalus L.) formerly (Agropyron pauciflorum L.). Field and greenhouse experiments were performed to identify selectivity between two herbicide compounds and the crops studied. Foxtail barley was extremely sensitive to both compounds at the 1X rate whereas 'Nortran' tufted hairgrass was tolerant of propoxycarbazone. 'Gruening' alpine bluegrass and 'Wainwright' slender wheatgrass were not tolerant of either compound at the full rate but showed greater tolerance of propoxycarbazone at the 1/2X rate. Propoxycarbazone is a potential tool for foxtail barley control in all three native grass species used for seed production in Alaska.