Farmers can now measure and, as a result, better manage weeds on their property with the help of a phone app developed
by AgResearch.
The ‘Grassland Cover Estimator App’ provides an estimate of the percentage of a paddock that is occupied by a weed. This
enables the productivity lost due to the weed to be calculated and used in a cost-benefit analysis for a proposed
control operation.
The App was launched in February and AgResearch Principal Scientist Graeme Bourdt said it will have broad appeal among a
wide variety of users working directly or indirectly in the pastoral sector, including farmers, regional council
biosecurity officers, rural professionals, farm advisors, scientists and students.
“The app has already been downloaded by 45 users across New Zealand, China, UK, France, Germany, USA and Canada.”
Dr Bourdt said the feedback from farmers had so far been very positive.
“The catalyst for developing the app came from a Sustainable Farming Fund weed management project that I am involved in
led by Golden Bay dairy farmer, Corrigan Sowman.
“We’ve been comparing different management tactics for giant buttercup in on-farm field experiments with a view to
developing a decision support system for management of this weed.
“It’s a simple-to-use but powerful, enabling measurement of the cover of any component of a natural grassland or sown
pasture including any weed, desirable pasture plant, diseased plants, bare ground etc. The app keeps track of ‘present’
and ‘absent’ observations made by the user and uses this data in a method known as ‘Step-point Analysis’ to calculate
the percentage of the paddock that is covered by the weed or other component of interest. The app also enables the data
to be exported for more detailed analysis including, for example, mapping of the cover estimates for the paddocks on a
farm.”
The precision and accuracy of the cover estimates generated by the app are the subject of an ongoing collaboration
between AgResearch and Prof. Joe Neal, a weed science extension specialist at North Carolina State University. The
results from this study, involving data collection in pastures and simulation modelling, will inform sampling protocols
for using the app and will be published in an international weed science journal.
Dr Bourdt said there’s already been significant interest from other external stakeholders in New Zealand to further
develop and expand the capabilities of the app. The app is available, free to use, on the Google Play Store and the
Apple App Store.