Australia’s experiencing one of the wettest seasons with the third consecutive year of La Niña causing widespread rain and flooding.

Prolonged rain and flooding not only damages crops, but increases the risk of weeds, plant pests and diseases establishing in new areas.

Floodwater does not respect property fences or regional boundaries. An uncontrolled body of water adds disease pressure that requires extra vigilance when it comes to spotting anything unusual in paddocks and grain crops.

Increased risk

Flood conditions increase the risk of a once localised weed, pest or disease spreading to become one of regional significance.

What was once a property with intact boundaries, entry controls and hygiene regimes may now be awash with topsoil and plant or animal matter from kilometres away, which is an ideal way for new weeds, pests and diseases to spread.

Weeds you have seen along a waterway, on a farm or roadside reserve could now be establishing in your best paddock.

Vigilant surveillance

It is crucial to keep a close eye on paddocks in the coming months. Especially areas that have been flooded and left with debris, should be monitored carefully, both before planting and during the 2023 growing season.

If you spot anything new or unusual, it needs to be identified and managed quickly. Immediately report an unusual plant pest or disease by calling the Exotic Plant Pest Hotline on 1800 084 881.

Control movement

In addition to floodwaters, the actions of farm workers, contractors and visitors can also spread pests and diseases. Machinery, livestock, fodder, vehicles and clothing can all carry infested soil or plant material, especially in muddy conditions.

Anyone moving on to or off a farm has a role to play in preventing the spread of pests and diseases through vigilance and adherence to basic hygiene principles.

Importing grain and fodder for livestock from further afield due to local shortages, also poses a risk for hitchhiker weeds, pests and diseases spreading. Good management practice would be to enquire about any issues at the source property, and if possible, feed out in a quarantine paddock that can be closely monitored for germinating weeds.

Remove the green bridge

Spilled and non-harvestable grain that remain in paddocks, washed in and resident weed seeds, can all germinate quickly in favourable conditions. These opportunistic seedlings form a green bridge for pests and diseases to survive between crops.

As soon as paddocks are accessible, volunteer seedlings should be removed to prevent pest and disease inoculum build up, threatening the 2023 winter crop.

The Grains Farm Biosecurity Program (GFBP) aims to support management practices designed to prevent, minimise, and control the introduction, spread and distribution of pests such as weeds, insects, nematodes, molluscs, bacteria, fungi, and viruses. Early detection through continuous monitoring and surveillance is critical.

The GFBP is funded by grain grower levies through Grain Producers Australia (GPA), administered by Plant Health Australia.

For more information about grains farm biosecurity in your region, contact your state’s grains biosecurity officer or visit the Grains Farm Biosecurity website.

Useful resources:

By Jim Moran, Victoria Grains Biosecurity Officer