Virtual weed control
GroundCover™ Issue: 106
Recently launched at the Global Herbicide Resistance Challenge conference, the Ryegrass Integrated Management model is a decision-support system that enables growers and advisers to determine the most profitable and sustainable way to tackle herbicide-resistant ryegrass in cropping systems
An Australian Herbicide Resistance Initiative (AHRI) workshop using the Ryegrass Integrated Management (RIM) model set Western Australian grain grower Lance Turner on the path to overcoming his herbicide-resistant annual ryegrass problem.
Lance discovered herbicide-resistant ryegrass on his 4000-hectare Corrigin property in 1996 following three years of a continuous wheat/lupin rotation. Although he was advised to start dropping paddocks out of production, with the help of the RIM workshop he embarked instead on an aggressive and integrated management approach to ryegrass control.
“The AHRI RIM workshop was a turning point for the way I farm,” Lance says. “From then on my mission was to control the weeds first. Lower inputs and better yields followed.”
Having towed a chaff cart for the past seven years, about 95 per cent of Lance’s paddocks now have low levels of ryegrass, enabling him to reap the production benefits of sowing early each year.
RIM is now another tool in Lance’s integrated weed-management approach.
Developed by the AHRI, RIM has recently been updated with GRDC support. The new RIM version is available to download for free from the AHRI website (www.ahri.uwa.edu.au). The software includes both strategic and tactical weed control methods.
Integrating ryegrass biology, agronomy and economics, RIM allows the user to observe the predicted effects of ‘what-if’ scenarios on ryegrass plant and seed populations, crop yields, and paddock economic returns over a 10-year period.
AHRI researcher Myrtille Lacoste, who developed the new RIM package, says RIM is a convenient way to test the profitability of ryegrass control methods before putting actual dollars at risk.
Computer simulations enable us to assess future scenarios so that we can make better decisions in the present. RIM won’t replace your expert judgement, but it will give you one more piece of evidence so that you can make important management changes with increased confidence,” Ms Lacoste says.
RIM helps growers tackle questions such as:
- What combination of control options and rotations will provide the best overall weed management system in the long term?
- How much could herbicide resistance cost me and how can I maintain my income if I am not able to rely on some herbicides into the future?
- To what extent can I diversify my weed management system and remain cost efficient?
- What is the economic value of tactical methods such as green manuring or mouldboard ploughing for controlling weeds?
- Is it worth investing in harvest weed-seed-control machinery and, if so, under what circumstances will it be economic?
Users choose from seven crop and pasture enterprises and more than 40 field operations to build, evaluate and compare 10-year cropping and ryegrass management strategies.
08 6488 7872, firstname.lastname@example.org
Download RIM and its user manual and video for free from: www.ahri.uwa.edu.au/rim
GRDC Project Code UA00124