Adaptive changes of farmers to the continued invasion of Senecio madagascariensis Poir. (fireweed) in pasture-based systems

Senecio madagascariensis Poir. (fireweed) is a rapidly invading poisonous weed of temperate and subtropical pastures across several continents and islands worldwide. While the geographic spread of pasture weeds, such as fireweed, can be relatively readily monitored, it is often farmer perceptions of weed impact that form the imperative for their management. In order to assess the types of adaptive changes that farmers may consider to the continued invasion of weeds in pasture-based systems, in 2011, we repeated a published 1985 farmer survey in fireweed-impacted regions in Australia to investigate: its continued spread; changes in the perceptions of its importance; and resulting changes in management. Fireweed had spread to new regions and was better established in previously lightly infested regions. It was less likely to be considered troubling by respondents when it was new on their farms, or had been present for an extended period. The effectiveness of a control method was only one of several factors driving adaptive changes in pasture weed management amongst survey respondents. Use of some approaches had declined alongside a perception that they were relatively ineffective, while the level of use of other reportedly successful techniques remained static, indicating major impediments to adoption. Weed invasions are by definition dynamic, and landholder perceptions of pasture weeds appear equally dynamic. As poisonous Senecio species spread around the world, the findings of this Australian research emphasise the need to understand how farmers adapt to weed invasion. Policymakers and landholders can benefit from such research for Senecio and other important weed species, by exploring the perceptions that may drive successful adaptive management of these species on-farm.