Interactive protection tool a first

HortPlus director Mike Barley says the upgrade was the first time that specific advice on fungicide use had been included in the MetWatch platform for plant disease management.

“It will allow plant producers to be more accurate and efficient with the use of chemical sprays to combat myrtle rust this season. This is especially important as myrtle rust spreads down the country,” he explains.

Rather than spraying seedlings on a typical 14-day cycle, the Myrtle Rust Climate Model enables producers to time spray applications based on real time disease risk, significantly reducing the number of applications required.

“Earlier versions didn’t allow for specific spray information, so modelling was based on average spray responses combined with MetWatch weather data,” Barley adds.

“The new update is based on the actual active ingredients being used at each nursery, so the spray management advice is much more precise.”

Plant & Food Research scientists have been conducting trials on myrtle rust management using the online tool, which proved invaluable in providing information on spray efficacy and the Myrtaceae species that are most or least susceptible to myrtle rust.

As an example, they have discovered that mānuka is more resistant to myrtle rust so doesn’t need as much spraying as was previously thought.

To access the update, growers should go into the Disease/ Myrtle Rust Cumulative Risk section of the online tool, then click on the new ‘Add Spray’ button then select the date and chemical sprays used in their nursery.

The interactive tool will then indicate, in graph form, the next ideal spray timing (Action Threshold) based on the applied sprays and local weather conditions including temperature, humidity and rainfall.

Trials and further development of the platform will continue and over time may include other disease climate models, such as those affecting fruit and vegetable growers.