Blackleg Management Guide, 2018 Spring variety ratings

Quantify the risk, paddock by paddock

Blackleg can cause severe yield loss, but can be successfully managed. This guide and the BlacklegCM app will help growers and advisers effectively manage canola crops against blackleg infection and determine if there is a high-risk situation and what practices need to change to reduce or prevent yield loss. Follow the four steps, in sequence, from this management guide.

Key Points

• Never sow your canola crop into last year’s canola stubble.
• Choose a cultivar with adequate blackleg resistance for your region.
• Relying only on fungicides to control blackleg poses a high risk of fungicide resistance.
• If your monitoring has identified yield loss and you have grown the same cultivar for three years or more, choose a cultivar from a different resistance group.
• Monitor your crops in Spring to determine yield losses in the current crop.

Leptosphaeria maculans, the causal agent of blackleg disease, is a sexually reproducing pathogen that may overcome cultivar resistance genes. Fungal spores are released from canola stubble and spread extensively via wind and rain splash. The disease is more severe in areas of intensive canola production.