A NEW analysis tool is now available to help Australian grain growers weigh up the pros and cons of summer weed control in different scenarios. 

The $ummer Weed Tool, a Grains Research and Development (GRDC) investment developed in partnership with CSIRO, allows growers to generate information on yield benefit and return on investment scenarios- comparing immediate versus delayed weed control. 

The app has been designed for use by growers in paddocks across Australia's broadacre cropping regions, providing a report based on several metrics including soil type, soil water, grain price, fertiliser costs, weed control costs and weed density. 

GRDC Weeds Manager, Sarah Morran said summer weeds cost Australian growers in southern and western regions over $350 million in lost yield annually, with estimates around $23 per hectare and $13/ha respectively.

"In comparison, summer weed control can range from between $14/ha and $19/ha, so it is a critical consideration for growers in terms of assessing what is right economically for their farming situation," she said.

"We know the returns from summer weed control can be highly variable due to seasonal variability, weed type and the following winter growing season.

"This new weed decision support tool aims to give growers and their advisers, a better understanding of the economics, so they have the confidence to adopt and implement effective weed control strategies."

CSIRO principal research scientist, Everard Edwards, who gathered the data to support the new tool, said it is particularly relevant to western and southern states, and dryland cropping systems in southern New South Wales.

"In our validation trials in Western Australia, South Australia, New South Wales and north-west Victoria, we found that the yield penalty for not controlling summer weeds in a timely manner could vary greatly – anywhere from less than 100kg/ha, up to 640kg/ha," Dr Edwards said.

"By combining important factors such as soil type, soil water, wheat price, weed control cost, fertiliser price and weed load, the app can generate figures on the expected increase in yield potential due to water, the probability of gaining at least 0.2 tonnes per hectare in yield and the expected nitrogen benefit.

"In addition, it provides figures on the probability of at least 10kg/ha nitrogen benefit, the probability of gaining at least $20/ha due to extra water and nitrogen availability and the overall potential return on investment."

Dr Edwards said a key feature of the app was its ability to work offline, and importantly, in the paddock.

"Critically for growers, this app uses an internal database to generate the figures, so mobile signal or internet connection aren't required for it to work effectively," he said.

"It is a genuine in-paddock decision support tool that growers can use to help understand differences between yields and seasonal probabilities."

MORE INFORMATION 

The $ummer weeds decision support tool can be downloaded from the Apple App Store (link available on mobile devices) or Google Play.