A number of Australasia’s top research institutions have joined forces to develop diagnostics tools that aim to keep pests at bay and maintain good biosecurity across plant production industries. In this article, AUSVEG’s Ian Thomas outlines the extension activities being undertaken as part of the Boosting Diagnostics for Plant Production Industries project.

Plant pests and diseases have been the burden of growers since the beginning of agriculture. The disruption to trade while diagnostic decisions are being made can be costly to businesses and trade, and reducing this timeframe will be crucial in the coming years as disease and pest pressure rises due to increased global trade and climate uncertainty.

To prevent incursions and stay on top of good biosecurity practices, modern, quick, and accurate diagnostic tools need to be available to growers and diagnosticians Australia-wide.

In 2019, a Rural R&D for Profit program entitled Boosting Diagnostic Capacity for Plant Production Industries (or Boosting Diagnostics) commenced. Led by the Grains Research and Development Corporation, Boosting Diagnostics seeks to increase Australia’s ability to detect, contain, and eradicate plant pests and disease outbreaks.

In recent years, the development of DNA identification tools such as LAMP, qPCR, and MinION (Oxford Nanopore) make it easier than ever to identify pests and diseases on-farm, but for these tools to be effective there is a lot that must first happen. Assays for identification must be developed and tested, both in the field and the laboratory. Reference samples must be secured and categorised. Protocols need to be developed, tested, and tested again.

Boosting Diagnostics supports the development of new diagnostic tools, underpinned by strong communication and extension activities to raise awareness of these tools among diagnosticians and industry. This will assist in early, rapid, and accurate detection of pests and diseases on-farm and allow swift and precise responses from industry.

It is not solely about detecting the presence of pests and diseases, but also their absence. Australia is thankfully free from many pests and diseases that plague the rest of the world. This absence – and our ability to prove it – allows Australian growers access to markets all over the world. The extra capacity provided by Boosting Diagnostics will help provide strong scientific evidence that our growing regions are free from pests and diseases.

Extension and communication activities

Throughout the remainder of 2021 and 2022, AUSVEG will be coordinating the extension and communications component of Boosting Diagnostics to deliver the many and varied project outcomes into the hands of those who will use them day-to-day. These activities will be delivered in two streams: the Diagnostic Stream and In-field Stream.

The Diagnostics Stream will focus on delivering developed technologies, protocols and expertise to diagnosticians and lab-based personnel through relevant diagnostic events and activities. Meanwhile, the In-field Stream will focus on in-farm triage and translating the diagnostic knowledge to actionable on-farm capacity and capability. This component will target professionals working in the field, ranging from agronomists, field pathologists, biosecurity officers, state surveillance staff and growers.

AUSVEG will run seven workshops in different regions across Australia, each focusing on the pests and diseases impacting each region’s industries and addressing their specific requirements. During this process, AUSVEG will increase the awareness and knowledge of selected National Priority Plant Pests (NPPPs), provide updates on project activities, and deliver updated resources to diagnostic personnel across the plant production industries.

Spotted winged drosophila (Drosophila suzukii) larvae. Image courtesy of Hannah Burrack, North Carolina State University, Bugwood.org.

Pest and disease targets

Boosting Diagnostics will focus on a variety of target plant pests and diseases affecting a broad range of plant industries. These include the cyst nematodes of the genus Heterodera (pests of grains and vegetables), Xanthomonas citri subsp. malvacearum (the cause of bacterial blight of cotton), and spotted wing drosophila (Drosophila suzukii; a potential threat to berry and wine production), among many others. The individual projects are broad and varied, and approach the issue from different angles.

CSIRO Research Scientist Dr Mike Hodda is working to organise the complicated taxonomy of Heterodera nematodes.

“We are building a collection of local and exotic species so that we can work out what is in Australia and what is not, and how to distinguish them,” Dr Hodda said.

Xanthomonas citri subsp malvacearum symptoms on cotton. Image courtesy of Clemson University – USDA Cooperative Extension Slide Series, Bugwood.org.

“The benefits to vegetable growers will be better recognition of cyst nematode issues; faster, cheaper and more reliable diagnostics; better management options; and enhanced market access through area freedom.”

Cyst nematodes can occur in many crops but are notoriously difficult to diagnose as symptoms of their damage are easily mistaken with nutrient deficiency or drought stress. Dr Hodda advises that growers look for damage that occurs in a lens or oval shaped area and is pointing in the direction of cultivation, as well as expanding by a few metres each year.

“The nematodes themselves are just visible to the naked eye as white, beige, or brown balls about the size of pin heads protruding from roots,” Dr Hodda explained.

CSIRO is putting a call-out for samples from any vegetable growers who believe they may have cyst nematode issues in their crops.

“To submit samples, growers should collect a handful of affected roots into one plastic bag, and a few hundred grams of surrounding soil into another bag, label them both with your name, location, and the crop, and keep them cool.”

Further tools

Dr Andrew Weeks from Cesar Australia is developing diagnostic tools that use environmental DNA (eDNA) to identify pests without needing direct insect collection. eDNA is left behind in frass; that is, excrement from the digestive system of various pests, or on feeding sights. It can be used to help identify pest species presence – even when they may not be found.

“The eDNA diagnostic tools, sampling approaches and factsheets developed through this project will enable more rapid identification of some high priority plant pests, allowing more effective management intervention to be undertaken to prevent or limit incursions or outbreaks,” Dr Weeks said.

“The project will assess the feasibility of moving the technology into the field. We envisage the technology could be rolled out in some form within the next two-to-three years.”

Each Boosting Diagnostics sub-project is a small piece of a larger puzzle. As each one falls into place, the picture of what improved diagnostics and better biosecurity looks like for Australia’s vegetable growing sector will begin to take shape.

Industry collaboration

The Boosting Diagnostics for Plant Production Industries project is a partnership between the Grains Research and Development Corporation; Cotton Research and Development Corporation; Horticulture Innovation Australia Ltd; Wine Australia; Sugar Research Australia Ltd; Forest and Wood Products Australia Ltd; AgriFutures Australia; Commonwealth Scientific and Industrial Research Organisation (CSIRO); Minister for Primary Industries and Regional Development (SARDI); Western Australian Agricultural Authority; Department of Jobs Precincts and Regions (VIC); Department of Agriculture and Fisheries (QLD); Department of Primary Industries (NSW); Department of Primary Industry and Resources (NT); Biosecurity Tasmania; Plant Health Australia; Plant and Food Research; AUSVEG Ltd; Cesar Pty Ltd; and Bio-Protection Research Centre.

Find out more

Any vegetable growers who would like to submit samples to the CSIRO’s nematode project can contact Dr Mike Hodda on 02 6246 4371 or email mike.hodda@csiro.au. Unfortunately, the project is currently unable to collect samples from potato growers.

For further details about the Boosting Diagnostics project, please contact AUSVEG Project Officer Madeleine Quirk on 03 9882 0277 or email madeleine.quirk@ausveg.com.au.

This project is supported by the Grains Research and Development Corporation through funding from the Australian Government Department of Agriculture, Water, and the Environment – as part of its Rural R&D for Profit program – and the Cotton Research and Development Corporation, Hort Innovation, Wine Australia, Sugar Research Australia, and Forest and Wood Products Australia.

Cover image: Scouting a citrus crop for white fly. Image courtesy of Shutterstock.