Kearney Agricultural Research and Extension Center Director Jeff Dahlberg is collaborating on a project looking for new management options for the weed. So how big of an issue is it? “It’s the number one world wide weed,” Dahlberg says. “It’s everywhere. It looks like it’s moving further north as the weather warms up it’s a little more aggressive.”
Dahlberg says resistance has complicated the issue and the fortitude of the weed is why researchers are looking now before resistance becomes an even bigger problem.
Manage johnsongrass now
From UC IPM Website: This weed can be a serious problem, especially in young orchards. It can be controlled by repeated tillage during the dry summer months. However, the soil must be fairly dry; otherwise the rhizome buds may sprout. Repeated applications of selective postemergent herbicides (fluazifop-p-butyl [Fusilade] or glyphosate) will often be required for control of the grass. Geese are also effective at controlling the grass in organic orchards. In new plantings, trifluralin (Treflan) or norflurazon (Solicam) will control seedling johnsongrass, but not established (rhizomatous) johnsongrass. Read more from UC IPM website.