WA CITRUS update

Good coverage and calibration lay foundations for good pest management

Following our theme of looking to the future and integrated pest management, our field day event in May included a demonstration of a drone that does spray application.

Words Bronwyn Walsh, Industry Development Manager, WA Citrus and Rachelle Johnstone, DPIRD

THE use of drones in agriculture is being explored across the different industries. In challenging weather conditions, Gary Rentenaar and Judy Zhu Australia Agritech demonstrated the spraying capability of the DJI AGRAS T40 drone. The DJIM3 drone. A map of the orchard is uploaded into the software. This is then used by the spray drone to guide its route. Different sized drones are suitable for different tasks. They have been used in hilly country where it is difficult to get tractors and to replace helicopters. Their role in orchards in WA is still being explored. Current limitations include volume capacity and battery run-time.

The presentation also provided a reminder that effective spray coverage is essential for management of pests and diseases. Correct setup, operation and maintenance of equipment is important. Ensure good coverage by:

• Calibrating your sprayer at least annually

• Maintaining nozzles, pumps and hoses

• Choosing the right nozzle for the right job

• Calculating and checking speed of tractor

• Using water sensitive paper to review where your spray is landing in the crop

• Avoiding poor spray conditions (windy, wet weather)

• Regular tree pruning and skirting will help with spray penetration

Rachelle Johnstone from DPIRD introduced the presentation as part of the national integrated pest and disease management project. This is funded by national citrus levy and contribution by the Australia government.

Thanks to EE Muir for providing water sensitive paper and equipment for the spray application demonstration. Thanks to Agrifresh for hosting the event.

For future events more information was requested on new chemicals that are available and what to do when Citrus gall wasp arrives in your orchard.

Managing crop load with pruning

In July Steven Falivene from NSWDPI visited the afourer mandarin orchards in WA from Harvey to West Midlands.

Some of the lessons learned were:

• Different rootstocks influence the level of growth of the scion (variety grafted on to rootstock)

• Different ages of tree mean different levels of pruning may be required

• Different costs —hedging vs hand pruning

• Level of pruning —in some instances trees, and yield, can recover from a hard prune, but can affect cashflow in the short term

Pruning since trees were young has set the trees up with a good shape and relatively smooth yields from year-to-year.

Hedging once trees are bigger can be more cost effective.

Reviewing management practices will help to even out the load for next year. This year was a light year for early mandarins and a heavy year for late season mandarins.

Monitoring seasonal outlook and water management

The low water availability in some regions following dry summer and autumn conditions prompted a brief review of the seasonal outlook for May to July at the field day during May.

The implications of low rainfall on irrigation management decisions can be worked out by answering some key questions:

• How much water required in the root zone?

• How much water the crop uses each day?

• How much water the irrigation system applies?

These questions are discussed in a range of materials on the DPIRD website, including Citrus irrigation recommendations in Western Australia, www.agric. wa.gov.au/water- management/citrus-irrigationrecommendations-western-australia?page=0%2C1.

More information on training in irrigation basics and to get the best out of soil moisture monitoring technologies was requested by those at the field day.