Diseases in Canola

Broad disease constraint resources are outlined in the Agronomists Toolkit. Specific disease categories are listed below:

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White leaf spot

Constraint - White leaf spot

Description

  • A white-spot forming fungal disease that is mainly a problem in wet weather

  • White leaf spot survives on canola stubble between crops and after prolonged wet weather in autumn/winter, wind-borne spores are produced that cause primary leaf lesions on canola

  • Damage is worse in wetter areas 

Symptoms

  • Commonly infects canola seedlings on lower leaves

  • Leaf, stem and pod lesions are greyish-white to light brown and up to 10 mm in diameter

  •  In severe infections, lesions can merge and lead to premature defoliation 

Damage

  • Yield penalty is very rare

Management

White leaf spot infection is not usually severe enough to warrant control. Crop rotation, control of volunteer canola and cruciferous weeds, providing adequate nutrition, and isolation from the previous year’s infected canola stubble will help to reduce the risk of infection.

 

Links and Resources

AOF - White leaf spot

Page contains information on description and management.
DAFWA - Diagnosing white leaf spot

Introduction, what to look for in paddock and plant, what else could it be, where did it come from, and management strategies. Page last updated 2014.
DEPI VIC - Canola diseases. White leaf spot

The section on white leaf spot contains introduction, symptoms, disease cycle, and management. Published 2008, page last updated 2009, page reviewed 2010.
DEPI VIC - Identification and management of field crop diseases in Victoria. White leaf spot

Page 146. Table 11.1 gives a key for canola diseases at different stages of plant growth. Page 155. Introduction, symptoms, disease cycle, and management. Published 2012.
GRDC - Back pocket guide. White leaf spot

Page 2. Introduction, symptoms, disease cycle, and management. Published 2013.
GRDC - Best Practice Management Guide. White leaf spot

Page 65. Introduction, symptoms, disease cycle, and management. Published 2009.