Weeds are estimated to cost Australian agriculture more than $2.5 billion per year, with in-crop weed competition costing around $1 billion per annum for Western Australia (WA). The overall annual weed cost to Western Australian grain growers is ~$927 million, equating to $117 per hectare. The most expensive weeds in relation to yield loss are annual ryegrass, wild radish and wild oats. WA growers spend 3 times more than any other state on harvest weed seed management ($13 million nationally) using tools like windrow burning, chaff carts, seed destructor and other methods. As a result of the importance of this issue, GRDC investment into the area of herbicide resistance alone over the past 25 years has returned a benefit-to-cost ratio of $3.50 for every dollar invested (Llewellyn et al 2016), however weeds with herbicide resistance are an increasing problem in grain cropping enterprises.

GRDC’s Regional Cropping Solution Network (RCSN) Geraldton and Kwinana West port zone members are interested in finding out more about alternative options for weed control that reduce their reliance on glyphosate and at their last meeting in August 2018 ranked understanding of why weeds grow where they do; and concern over losing glyphosate very highly, ranking them 1st and 3rd respectively as impacting most on their profitability. Coupled with the cost of controlling weeds is the trend towards reducing our reliance on glyphosate to reduce risk of glyphosate resistance and better manage weed burdens; as well as negative public perception around the use of glyphosate in our food systems.

The aim of this investment is to extend the knowledge and a whole of systems approach through a series of workshops about why weeds grow where they do; and how management decisions impact on the density, type and range of these weeds in the Geraldton and Kwinana West port zones using an expert panel consisting of growers, consultant, advisors and researchers.