Investigation of crop management strategies for control of herbicide-resistant blackgrass (<i>Alopecurus myosuroides</i>)

Abstract

Different management strategies to reduce high black-grass (Alopecurus myosuroides) infestation levels are investigated in two selected fields situated in Wendhausen (Germany) since autumn 2016. The black-grass populations on both fields show resistance against ACCase inhibitors as well as partial resistance against ALS inhibitors. The tested strategies include different tillage systems, sowing dates, seedbed preparation and herbicide application times. The two tillage systems consist of inversion and non-inversion tillage. For seedbed preparation a conventional method (using a cultivated seed drill) is compared to a false seedbed prepared 3 to 4 weeks before drilling, followed by direct drilling. Results on black grass density development from the first year of trials show that inversion tillage, especially in combination with a false seedbed, led to the highest reduction in black-grass density. The lowest reduction was achieved with non-inversion tillage and conventional drilling. Overall, a complete control of black-grass will be very difficult to achieve while maintaining a crop rotation consisting only of winter crops.