Blackleg risk forecast high on South Coast

DPIRD's blackleg forecasting model uses past weather data to determine which areas are most at risk.

The modelling also assumes four milimetres of rainfall each week from the date of the forecast (date)

High rainfall zones such as the Southeast and Southeast Coastal regions are more susceptible to the fungus due to more moisture around the crops, while the Wheatbelt and Mid West regions are less likely to be affected.

This season, the forecast predicts lower susceptibility to blackleg in crops sown in early April, with this risk increasing to crops sown in late April.

As rainfall becomes more likely, and temperatures drop, the conditions for spore release becomes favourable.

DPIRD principal plant pathologist, Jean Galloway, said autumn rainfall and cool temperatures was what initiated blackleg development.

The fungus survives on canola stubble, and releases spores after each rainfall event.

"These spores can infect susceptible canola seedlings if they are not protected," Ms Galloway said.

Ms Galloway said blackleg can be mitigated at the 4-6 leaf stage using a foliar fungicide.

"Another option for growers in a high-risk area who have planted a reasonable amount of canola and in a region with plenty of canola, is to use an in-furrow fungicide," Ms Galloway said.

DPIRD recommends using the BlacklegCM App to help decide if a foliar fungicide is going to be an economical option.

The blackleg forecast is updated weekly, and can be found here, along with the forecast for each site.

The forecast is currently showing a moderate blackleg risk in Corrigin, Narrogin, Kulin, Lake Grace, Darkan and Katanning, and high risk for towns between Mount Barker, Lake King and Esperance.

Information on managing blackleg