PestFacts WA

Canola blackleg risk forecasts

Map showing the relative current risk of spores coinciding with the seedling stage based upon Blackleg Sporacle model outputs for various locations in Western Australia, 29th April 2024. Map generated by: DPIRD blackleg forecast model.

DPIRD's blackleg spore maturity forecasts for Western Australia for the 2024 growing season have begun, and forecasts are available online. The latest forecast is current for crops sown up to 29 April 2024. This forecast will be updated weekly.

Blackleg crown canker can result in yield losses on susceptible canola varieties. The disease occurs when spores are released off the previous season’s or 2-year-old canola stubble. When these spores land on canola plants in the early vegetative stage this can result in crown canker forming. It is advised to avoid planting this year’s canola crop into paddocks that were sown to canola in 2022 or 2023.

The forecasts show the expected risk of blackleg infection occurring during the 4-6 leaf stage, relative to the date of sowing. For crops sown in the mid-to-late April period, the risk of blackleg spore showers coinciding with the seedling susceptible stage are high for some areas in the Albany and Esperance areas. Growers in these areas should consider using the BlacklegCM decision support tool to determine if they should apply a foliar fungicide to their canola crops during the susceptible 4-6 leaf stage. BlacklegCM is available for download from the Apple App and Google Play stores. This app previously only worked on tablets but is now also available for phones. For more information refer to DPIRD’s Blackleg CM page.

If you are using the BlacklegCM decision support tool you can manually enter the blackleg risk levels that relate to your sowing date and location into the app under the “Crop Circumstances – Spore maturity risk” section.

Further information

For more information, refer to DPIRD’s Canola blackleg spore maturity forecast for Western Australia page to check the blackleg model forecast for your district.

For more information about blackleg in canola contact Senior Research Scientist Andrea Hills, Esperance on +61 (0)8 9083 1144 or Principal Research Scientist Jean Galloway Northam on +61 (0)8 9690 2172. 

For more information about the blackleg risk forecast, or the BlacklegCM decision support tool, contact Principal Research Scientist Jean Galloway, Northam on +61 (0)8 9690 2172.

Article authors: Janette Pratt (DPIRD Moora) and Jean Galloway (DPIRD Northam).