Protecting Australia’s plant health: plant quarantine in an evolving biosecurity system †

As a geographically isolated and island continent, Australia has historically been protected from the impact of many damaging plant pests found overseas. However, the advent of modern transport systems and greater global trade in live plants, seed and plant products is increasing the movement of pests including invertebrates, pathogens, and weeds. Exclusion of these threats through an effective biosecurity system is essential to support and protect Australia’s agricultural producers and unique flora. Biosecurity measures must balance risk-based regulation with successful trade of goods, including live plants, seed and plant products. Although achievement of zero biosecurity risk is not a broadly practical outcome, geographic exclusion of threats is an effective approach to support and protect Australia’s unique environment. This is particularly important in the trade of live plants as nursery stock. Latent infection presents a significant hurdle for detection of plant pathogens in border inspections to exclude their entry with imported plants. Post-entry plant quarantine enables latent infection to be expressed as visible symptoms, while providing sufficient time for targeted testing of asymptomatic plants. Here we provide a synopsis of the pivotal role plant quarantine has and continues to play in Australia’s biosecurity system.