Integrated Weed Management (IWM) has outperformed conventional management in research conducted at Merredin by the WA Department of Agriculture. Vanessa Stewart of the Department of Agriculture said results in 2001 showed that, after three years of management, weed densities in all intensively treated plots were on average 10 per cent lower than the more conventionally managed plots. Intensive treatments included sacrificing grain production by cutting wheat for hay and green or brown manuring field peas. Increasing wheat eeding rates from 60 kgfha to 120 kg/ha also decreased the number of ryegrass seedheads produced by 30-50 per cent. Researchers have observed similar reduction levels in ryegrass seed production when field pea and barley seeding rates were doubled. This research is supported by growers and the Federal Government through the GRDC.

Program 3 Contact: Ms Alex Douglas 08 9821 3333