Identifying and prioritising significant localised weeds

Not all weeds are generalists that occur over large geographic ranges and impact many crop types. Some weeds have discrete eco-physical niches which limit their distribution and growth. However, where they are well adapted, they can cause significant impact and cost on the relevant farming system. Whilst ecological research into the major, widespread weeds has occurred, growers continue to report problem weeds which are geographically limited in distribution. While their distribution may not be widespread, their impact is significant. Relevant examples of these weeds which have recently been raised through the NGN and other avenues are blue lupins in the northern agricultural zone of WA, annual saltbush in NW NSW and rosinweed in the Victorian Mallee. Due to their lesser-known status, the understanding of these weeds is limited. This lack of understanding hampers the ability to develop multi-year management strategies and results in growers falling back on reactionary tactics. Whilst local RDE efforts on these types of weeds naturally focus on control, and there is an opportunity to work on better understanding these groups of weeds as a collective approach.

The first step is identifying what these localised weed species are. Whilst we have data on estimated economic impact of the most troublesome cropping weed species from the Llewellyn et al. (2016) 'Impact of weeds' report, this cannot be used to evaluate recognised emerging weed species or the potential impact of new weeds. Through the investment DJP2007-002RTX – Weed species for potential research investment, a framework was developed to determine the priority for weed investment. This investment will utilise the framework to prioritise the localised weeds which have first been identified.