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

Weed alert: Red witchweed confirmed near Mackay

August 1, 2013
Witchweed damage on maize

Corn stunted by witchweed infestation. Little Rock, South Carolina, USA. Image: Randy Westbrooks, US Geological Survey, Bugwood.org

Biosecurity Queensland has confirmed that a serious exotic weed red witchweed (Striga asiatica) has been found near Mackay.

Biosecurity Queensland’s Director Invasive Plants and Animals, John Robertson, said samples were collected and have been identified by the Queensland Herbarium.

“While the weed has been confirmed on one property, information to date suggests that the infestation may be on a small number of other properties in the immediate area,” Dr Robertson said.

“The affected property is being placed under movement restrictions, which means no equipment, soil or plant material is allowed to be moved on or off the property without approval.

“While our priority is to minimise the biosecurity risks, we will continue to work with the owner to ensure some business continuity.

“Biosecurity Queensland has established a response program including a local control centre in Mackay.

“Potentially affected plant industries have been notified and Biosecurity Queensland is working with industry representatives to provide information to producers.

“We are urging producers to check their crops and report anything they suspect could be red witchweed. Further information on red witchweed is available from www.daff.qld.gov.au

Red witchweed is a root parasite that is exotic to Australia and affects the production of sugarcane and cereal crops by depriving them of water and nutrients.

Dr Robertson said this was the first confirmed detection of red witchweed in Australia.

Producers are urged to report any suspect weeds to Biosecurity Queensland on 13 25 23.

Witchweed on roots

Underground attachment to roots. USA. Image: USDA APHIS PPQ Archive, USDA APHIS PPQ, Bugwood.org

For producers who suspect they have red witchweed:

1. Report the plant immediately to Biosecurity Queensland on 13 25 23. 

2. Take photos of the infestation and store until you are contacted by Biosecurity Queensland. 

3. Do not attempt to remove any flowering plants, as this may allow the weed to spread tiny, dust-like seeds.  

4. Don’t move any soil, machinery or products (including mulch) that might contain soil off-site. This will help avoid spread of seeds to other properties. 

5. Seeds are tiny and can easily drop into the soil, enabling its spread. Therefore, keep the weed in place until Biosecurity Queensland can investigate. 

Visit the pages within the Essentials section of this site to find out how to prevent the entry and spread of diseases, pests and weeds onto your property.

Identifying red witchweed

Witchweed (Striga spp.) (Queensland Department of Agriculture, Fisheries and Forestry)