Weed control management strategies in conventional plough-based and non-inversion tillage systems,Irish tillage farms

A nationwide survey revealed that grass weeds are a challenge in both conventional plough-based (CPS) and non-inversion tillage (NIT) systems, with sterile brome (62% of farms) and spring wild oats (56%) being the most common. Blackgrass, Italian ryegrass, and lesser canary grass were less prevalent. Alarmingly, 38% of blackgrass-infested farms were unaware of its presence until identified by project staff. Herbicide-resistant grass weeds were widespread, with 22 resistant populations found on 18 farms, including resistance to ACCase and ALS herbicides. The project worked with ten Focus Farms, each facing different weed challenges, to develop and monitor management strategies to reduce grass weeds. Most farms saw reductions in grass weeds, though results were mixed. The co-validation programme provided valuable insights for a wider audience dealing with similar issues. The project also established weed screens and cover crop demonstrations to assess the impact of herbicide timing and stacking on grass weeds. While some cover crop demonstrations showed varying success in establishment and biomass growth, further research is needed to determine their long-term impact on reducing the weed seed bank.