Resistenzentwicklung bei Apera spica-venti in Niedersachsen

From 2007 to 2018, seed samples of Apera spica-venti were taken on 286 monitoring sites and the effectiveness of herbicides with different classes of active ingredients was tested in bioassays. Short, cereal-dominated crop rotations and repeated use of herbicides with the same mode of action enable Apera spica-venti to develop resistance to the active ingredient group of ALS inhibitors in Lower Saxony at almost two-thirds of the sites investigated. In addition to the active ingredient groups of ALS inhibitors and photosynthetic inhibitors, ACCase inhibitors are also affected by resistance evolution. In particular, propaquizafop and pinoxaden show a loss of efficacy at several sites investigated. However, cycloxydim and clethodim are still effective against Apera spicaventi, as are the soil active ingredients flufenacet (included in Cadou SC, Herold, Cadou forte and Bacara forte), pendimethalin (included in Malibu, Picona and Stomp Aqua), flurtamone (included in Cadou forte and Bacara forte) and propyzamide (contained in Kerb flo and Milestone). Further herbicide resistance evolution in Apera spica-venti can be reduced by rotation and combination of the active ingredients and accompanying agricultural measures.