Concerns over Blackleg in canola have increased in Western Canada throughout the past few seasons. With wet conditions this spring and increased canola production under shortened rotations, protecting a valuable canola crop is more important than ever.
With the potential to reduce lucrative canola yields, Blackleg is a disease that needs proactive measures to prevent infection. BASF Technical Specialist, Glen Forster, offers these tips to help growers protect their investment:
· Inspect your crop regularly: fields with the greatest risk for Blackleg are those where there has been a yield loss as a result of Blackleg in previous years and varieties with lower Blackleg disease ratings are grown under short rotations. Early symptoms of Blackleg appear as lesions on cotyledons and the first true leaves. Lesions are round or irregular, often dotted with numerous black pycnidia – as they mature they become greyish in colour and form on the stem.
· Exercise good crop management: Blackleg inoculum overwinters in crop residues and will be more prevalent where canola is seeded under tight rotations. Growers should use sound crop rotation as well as rotate canola varieties to help manage Blackleg inoculum levels on a farm.
· Apply fungicides preventively: fungicides should be used preventively before symptoms appear, effectively stopping the disease before it starts. These products can be applied at herbicide timing before the appearance of Blackleg disease symptoms.
· Keep your crop healthy: when plants are not challenged by disease, they are able to grow more efficiently and tolerate short periods of cold, heat and drought.
· Beware of other diseases: Blackleg is only part of the issue; Sclerotinia is an important canola disease that thrives in wet conditions. An early season application to control Blackleg followed by an application of a registered fungicide at the 20 to 50 per cent bloom stage to control Sclerotinia will provide the best possible protection for canola crops.