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Sclerotinia is being found in canola

  • Toodyay
  • Moora
  • Boyup brook
  • Kojonup
  • Katanning
  • Kendenup
  • Frankland
  • Kojaneerup
  • South Stirlings
A canola stem infected with sclerotinia
A canola stem infected with sclerotinia stem rot. Photo courtesy of: Bec Swift (DPIRD)
Sclerotinia sclerotes developing within infected canola stem
The developing sclerotes within the same infected stem. Photo courtesy of: Bec Swift (DPIRD)

Crop protection officer Bec Swift (DPIRD) and plant pathologist Jean Galloway (DPIRD) have found sclerotinia in Hyola 404 and 44Y24 canola crops near Toodyay. The Hyola 404 plants are infected mostly on auxiliary (secondary) stems rather than the main stems while the 44Y24 is showing more main stem infection. Sclerotes are developing within infected stems.

Canola with sclerotinia branch infection
Canola with sclerotinia branch infection. Photo courtesy of: Ravjit Khangura (DPIRD)

Plant pathologist Ravjit Khangura (DPIRD) has found low to moderate levels of sclerotinia in a number of canola crops in Moora, Boyup Brook, Kojonup, Katanning, Kendenup, Frankland, Kojaneerup and South Stirlings. Affected plants predominantly had lateral branches infections with low levels of main stem infections. Symptoms of sclerotinia infections were quite visible in paddocks with affected branches/stems showing bleached appearance.

Ravjit says sclerotinia infection causes premature ripening of plants and therefore poses the risk of premature shattering.

Look out for sclerotes in harvested seed

Harvest has begun for canola, lupin and pulse crops and growers are reminded to check their seed for the presence of sclerotinia sclerotes, especially if they are planning to retain their seed for next year’s crop.

Although the seasonal conditions were less favourable for sclerotinia this season, there is a high probability that the sclerotes may be mixed with the harvested seed in severely affected crops.

Ravjit advises that sclerotes are resting bodies of the fungus that are generally black in color, 2-20mm in length and can survive in soil for more than four years.

Growers are urged to carefully inspect their harvested seed and if they find large number of sclerotes, the seed should be graded. Ungraded seed used for sowing can inadvertently transfer sclerotes into the soil, which can later initiate the disease during the season.

Paddocks with heavy load of sclerotes should be rotated with non-host crops such as cereals for at least for 3-4 years to allow the sclerotes to decompose. Tillage and deep ploughing can also be employed to bury sclerotes to a depth more than 15cm.

Strategies for managing sclerotinia stem rot in 2018

Rotation, tillage and fungicides are currently the best strategies for managing scleronia stem rot, including:

  • Long rotations
  • Rotating with non-host crops
  • Avoiding sowing close to last year’s infected crop
  • Using clean seed
  • Using foliar fungicide.

Further information about sclerotina stem rot can be found at;

For more information on canola sclerotinia contact Ravjit Khangura, Plant Pathologist, South Perth on +61 (0)8 9368 3374 or Ciara Beard, Plant Pathologist, Geraldton on +61 (0)8 9956 8504.