Providing practical information to help you protect your farm from biosecurity risks

Don’t let biosecurity slip in the clean-up after the floods

March 30, 2012

Victorian floodingFarmers are urged not to let biosecurity practices slip in light of the recent flood events across much of the south east of Australia. As the clean-up continues, it is timely to consider a few biosecurity issues in preparation for sowing the winter crop.

The movement of flood water across paddocks will have brought with it debris and trash from adjacent paddocks and farms, and from outside the district. This trash could carry any number of foreign weed seeds, fungal diseases or pests.

Areas which have had flood trash pass through them or deposited on them should be monitored carefully, both before planting and during the growth of the next crop. Any weeds, pest or diseases which emerge should be dealt with as quickly as possible.

NSW Grains Biosecurity Officer Louise Rossiter advises that from a biosecurity point of view, there are a number of potential threats that the movement of significant volumes of flood water can bring about.

“It’s important to consider water flow and trash in deciding what crops to sow where in 2012. Rotation practices you have used in the past may no longer be effective as the flood water will spread disease by infecting adjacent paddocks” she said.

“As an example, management of Ascochyta in chickpeas includes ensuring that it is not planted within a certain distance from a previously infected crop. But if floods have crossed the paddock, diseased stubble may have moved from an infected paddock into a paddock that used to be clean” said Ms Rossiter.

Victorian Grain Biosecurity Officer Jim Moran says that weeds are always a problem after floods. “It is important to remember that weed seeds can be brought in on flood water and trash. They may also be introduced with fodder drops to stranded stock” he said.

Another consequence of the floods and a wet summer is volunteer wheat and barley seedlings. This is a significant issue which could cause a disease epidemic if not controlled.

“Leaf diseases in crops in the 2011 season may be carried through to the next season. Mild temperatures and wet weather over the summer can result in a ‘green bridge’ of volunteer wheat and barley seedlings that can carry diseases” said Mr Moran.

“If these self-sown seedlings are not eliminated well before planting of the winter crop, they will provide an ideal source of infection and inoculum build up for the 2012 winter crop” he said.

Some producers will need to employ contractors to fix waterways and roads, replace fences or to just keep up with the extra work load. Remember to keep a record of who has been on your property and where they came from. It is also important to ensure that any vehicles or equipment have been cleaned down before entering your farm.

Here are five key activities to consider in the flood recovery process:
1. Take notes about where water has run and or lain across your property and any trash it has left deposited. This is so you can keep an eye on these areas in the future.
2. Eliminate the green bridge by spraying or removing any weeds or volunteer seedlings as soon as possible and well before sowing the next crop.
3. Keep an eye out for weeds in any areas where there have been flood waters and trash deposits, or fodder drops for flood affected stock.
4. Make sure any vehicle or equipment coming onto your property is cleaned down before entering the property, and ideally before leaving your property.
5. Keep records of contractors that come onto your property to repair any damage or do recovery work.

The National Grain Farm Biosecurity Program is funded by grain grower levies through Grain Producers Australia, administered by Plant Health Australia.

If you see anything unusual, call the Exotic Plant Pest Hotline on 1800 084 881. For more information or a free copy of the Farm Biosecurity Manual for the Grains Industry please contact:

Rachel Taylor-Hukins at NSW DPI in Orange on 0409 945 069
Jim Moran at Vic DPI in Bendigo on 0418 377 930

Photo: Courtesy of Jim Moran, Victorian DPI