Caution: Pest control ahead!

By Gabrielle Stannus

Think your business is safe from biosecurity threats because you do not import plants? Think again! At the Growing Edge conference in February, Lois Ransom from the Department of Agriculture and Water Resources spoke of the difficulty in managing medium risk nursery stock given emerging disease risks. Ransom warned growers who import that they need to focus on offshore management of diseases of concern, i.e. that they know and work with their supply pathway. However, John McDonald, Nursery and Garden Industry Australia’s (NGIA) National Biosecurity Manager reminds all growers that they are also at risk from non-vegetative materials travelling into Australia and by plant material travelling within the country.

There are only a small number of NGIA members who currently import plant stock into the country. However, that does not mean the industry is safe from overseas threats. “Our industry is heavily exposed but not necessarily responsible for bringing the threats into this country” says McDonald. As air and shipping freight movement increases across the world, the risks that Australia will be exposed to more harmful pest, disease and weed threats via contaminated imports is increasing. The brown marmorated stink bug ( Halyomorpha halys ) 1 arrived here in a shipping container unrelated to plant production yet has the potential to cause the complete cessation of nursery stock movement if a businesses is caught up in a biosecurity zone.

Tomato-Potato Psyllid

Once in Australia, pests, weeds and disease can severely disrupt the livelihoods of growers and retailers. The recent incursion by the Tomato-Potato Psyllid ( Bactericera cockerelli) into Western Australia in 2017 is no exception. This psyllid is a vector for Zebra Chip, a disease complex caused by the bacterium Candidatus Liberibacter solanacearum (CLso) 2. Whilst Zebra Chip itself has yet to be detected in Western Australia, the government has introduced management controls to restrict the movement of its insect vector which is now inferred asestablished in that state.

You do not have to be responsible to be affected by emerging plant pest or disease detection. If within a management zone, you may be fully or partially quarantined for short or long-term periods. You may find that you are prevented from moving your stock to normal markets, especially those interstate. In Western Australia, some businesses have never had TPP on their properties and may even be government –certified as pest-free production sites. Yet these businesses are currently unable to access some of their traditional markets as they are not allowed to trade known TPP host plants or there exist market access controls that are too costly to meet.

Other existing and emerging threats

In addition to TPP, current threats to growers include the brown marmorated stink bug ( Halyomorpha halys) in New South Wales and Western Australia, Banana Freckle ( Phyllosticta cavendishii) 3 in the Northern Territory, and Chestnut Blight (caused by a bark-inhabiting fungus Cryphonectria parasitica) 4 in Victoria. Emergency plant pest response plans are underway, aiming to eradicate these species in those locations.

The following pests and diseases are now considered endemic in the listed locations with controls on movement of host materials around Australia: Pyriform Scale ( Protopulvinaria pyriformis) 5 in Western Australia, Giant Pine Scale ( Marchalina hellenica) 6 in Victoria and South Australia, Cucumber Green Mottle Mosaic Virus in Northern Territory, and the Vegetable Leaf Miner ( Liriomyza sativae) 7 on Cape York and in the Torres Strait Islands.

Growers most likely to be affected by outbreaks of this nature include those contracted to deliver to large farms with properties across several states, or those growers holding the sole Plant Breeder Rights (PBR) to distribute their product nationally. This is especially true for ornamental, fruits, vegetables, vines and berries, and landscape stock.

What can you do?

Whilst you may not be able to stop the import of pest, disease and weed into this country, you do have control over what happens on your own property. Control who and what comes onto your property. Be vigilant in detecting biosecurity threats in your cropping/growing systems. Monitor crops, conduct site surveillance, and inspect your imports and dispatches regularly and thoroughly by using the BioSecure HACCP Guidelines. Most importantly, skill yourself and your employees across the processes and procedures associated with your business’ biosecurity. Report any potential impacts on your business to your state biosecurity agency as soon as possible.

For further help

The industry levy investment continues to fund research, development and extension programs to improve biosecurity controls. The Nursery Production Farm Management System (FMS) website hosts a well developed technical information library linked to the Nursery Industry Accreditation Scheme (NIASA). NIASA’s Biosecure HACCP Guidelines can help your business to assess your current and future pest, disease and weed risks.

To work out your obligations when importing and to understand any potential biosecurity threats, use the Federal Government’s online Biosecurity Import Conditions System (BICON) guidance tool.

Useful Links

Biosecurity Import Conditions System (BICON) guidance tool :
Nursery and Garden Industry Australia (NGIA) Biosecurity program:
Nursery Production Farm Management System:
Pest and disease fact sheets: