An Assessment of the Extent of Serrated Tussock Resistance in the Rowsley Valley, Victoria

Summary A 100 square km serrated tussock resistance survey in the Rowsley Valley of Victoria has confirmed that serrated tussock resistance is far more widespread than had been previously thought. Approximately 20% of surveyed sites surrounding a property previously confirmed with serrated tussock resistance to flupropanate had significant survival (resistance) to an application of label rate flupropanate compared to known susceptible serrated tussock plants treated at the same time. This suggests that resistance is not localised and should now be treated as a widespread issue. Any further Government investment that is deemed appropriate could be in the form of support for awareness and extension packages to affected land managers and/or ongoing research into new management techniques. This paper makes suggestions for how land managers can deal with the potential loss of flupropanate as a management tool and makes recommendations for how Governments and Industry could respond.