The NVT's blackleg role

Investment in screening program to help fight canola devastation caused by blackleg

Agronomy
Dr Steve Marcroft, Marcroft Grains Pathology. PHOTO Paul Jones

Dr Steve Marcroft, Marcroft Grains Pathology. PHOTO Paul Jones

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Screening programs aim to stop blackleg's devastating threat to the canola industry.

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Blackleg is deserving of its ominous common name as it is the most devastating of all diseases for canola and nearly brought the fledgling Australian canola industry to its knees in the 1970s.

Leptosphaeria maculans is the fungal agent of blackleg and its management is challenging, as it is a sexually reproducing fungus and therefore highly variable and continually evolving.

GRDC recognised the threat that blackleg posed to the industry and has invested in blackleg screening methods for canola varieties for many years.

It is imperative to use an integrated disease management program; this should not only include avoiding the previous year's canola stubble and using fungicides in high-risk situations, but also selecting a resistant canola variety suited to your region.

Screening program

GRDC recognised the threat that blackleg posed to the industry and has invested in blackleg screening methods for canola varieties for many years.

Since 2000, Marcroft Grains Pathology has been managing the screening program, which is provided as a voluntary service for all canola seed and breeding companies operating in Australia.

Blackleg is deserving of its ominous common name as it is the most devastating of all diseases for canola.

It screens all pre-release NVT canola entries and all commercial cultivars for their response to blackleg. Canola varieties are bred with a variety of combinations of different blackleg-resistant genes, but these genes can be overcome by the fungal disease.

This means that the rating of a canola variety's response to blackleg can change over time.

2019 Autumn Variety Ratings Fact Sheet Blackleg Management Guide. SOURCE NVT Online

2019 Autumn Variety Ratings Fact Sheet Blackleg Management Guide. SOURCE NVT Online

Blackleg population monitoring sites are established each year alongside NVT yield sites across all canola-growing regions in Australia to track changes in frequency of virulence towards specific resistance genes (resistance groups).

Strict protocols are used and data is objectively collected from each site. Data is analysed by the Statistics for Australian Grains Industry (SAGI) biometricians.

Ratings are updated twice a year and provided to industry through a management guide and the Blackleg CM app, both being GRDC investments.

GRDC Research Code GP1905-001SAX

More information: Dr Steve Marcroft, 0409 978 941, steve@grainspathology.com.au

Blackleg Management Guide

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