Impact of weed control strategies on resistance evolution in Alopecurus myosuroides – a long-term field trial

The impact of various herbicide strategies on populations of Alopecurus myosuroides is investigated in a longterm field trial situated in Wendhausen (Germany) since 2009. In the initial years of the field experiment, resistant populations were selected by means of repeated application of the same herbicide active ingredients. For the selection of different resistance profiles, herbicides with actives from different HRAC groups were used. The herbicide actives flupyrsulfuron, isoproturon und fenoxaprop-P were applied for two years on large plots. In a succeeding field trial starting in 2011, it was investigated if the now existing resistant field populations could be controlled by various herbicide strategies. Eight different strategies consisting of various herbicide combinations were tested. Resistance evolution was investigated by means of plant counts and molecular genetic analysis.