Battling blackleg? Infection may happen sooner than you think.

Blackleg is not a new disease and it can be found everywhere. For many years, it was effectively managed by planting resistant canola varieties and opting for longer rotations.

But over time, researchers have found blackleg races can change and adapt. According to the Canola Council of Canada, this has resulted in a steady increase in disease incidence in recent years. Another important piece of the puzzle is understanding how the timing of blackleg infections can impact canola.

Blackleg is an early-season disease

Early blackleg infections are responsible for the stem infections we see late in the year. After infection, the blackleg fungus moves from the cotyledon to the leaves, which then infect the stem. This restricts the plant’s ability to access moisture and nutrients important for final yield. In the most severe cases, stem girdling will cause lodging and may even cut off the plant completely.

A 2020 study published by Gary Peng at Agriculture and Agri-Food Canada (AAFC) in the Canadian Journal of Plant Pathology, stated effective control of early infection (at the cotyledon stage) can reap the biggest benefits for preventing later blackleg infections.

Typically, when we see severe disease symptoms at the end of the season, the damage is already done. But now, in addition to rotations and varieties, we have a new tool to protect canola at the cotyledon stage, offering a more sustainable, integrated approach to managing blackleg.

GO DEEPER: Watch Seedcare Technical Lead Ted Labun share key considerations when trying to manage blackleg.

Protect against blackleg with a seed treatment

Researchers have found that seed treatments provide the best chance to target the early, most damaging blackleg infections when cotyledons are especially vulnerable.

Research by Dr. Dilantha Fernando, at the University of Manitoba in 2019, showed that Saltro^® seed-applied fungicide from Syngenta is active on blackleg and protects cotyledons at emergence.

Lesion development on cotyledons of a moderately-resistant cultivar fourteen days after inoculation.
​​​​​​​Source: Dr. Dilantha Fernando, Rasanie Padmathilake, Dept. of Plant Science, University of Manitoba, 2019.

Saltro^® contains ADEPIDYN^®, a breakthrough Group 7 SDHI fungicide that’s highly effective against the blackleg pathogen. Saltro^® moves through the plant’s water-conducting system (xylem) and is taken up into the cotyledon so it’s present and active when needed most. This happens even when emergence is uneven or occurs over a period of time after planting.

Pairing the new with the tried and true

Saltro^® can be applied in combination with Helix^® Vibrance^® foundation seed treatment. This powerful pairing is known as Helix Saltro^® and protects against crucifer and striped flea beetles, Alternaria, seedling disease complex, and seed-borne blackleg in addition to early airborne blackleg.

In 2018 and 2019 Syngenta field research trials, canola seed treated with Helix Saltro^® showed significantly lower stem infection levels than untreated canola seed or current canola seed treatment standards.

Source: Syngenta research authorization trial in Mozart, SK, in 2019. Photo taken August 31, 2019.

Assessing the need for a blackleg seed treatment

When used as part of an integrated approach, Helix Saltro^® complements varietal resistance to the airborne blackleg pathogen.

According to the Canola Council of Canada, varieties with resistant genes will only protect against non-virulent blackleg races that are of the same type. In other words, the “key” (resistance gene) needs to fit the “lock” (target blackleg race) perfectly.

With Helix Saltro^®, there’s peace of mind from knowing that no matter what blackleg races are present in the field, the seed treatment will protect canola varieties suited to your farm and help ensure that they reach their full potential.

Using Helix Saltro^® also allows you to reduce disease inoculum on stem trash, lowering the risk of future blackleg infections.

Remember: seed treatments are just one component of an integrated management strategy. Helix Saltro^® should be used as part of a full blackleg management program that includes:

• Scouting (fall sampling)
• Crop rotation
• Variety selection
• Rotating genetics

GO DEEPER: Seedcare Technical Lead Ted Labun explains how to scout for blackleg in canola.

Performance evaluations are based on internal trials, field observations and/or public information.

Data from multiple locations and years should be consulted whenever possible. Individual results may vary depending on local growing, soil, and weather conditions.

Always read and follow label directions. Fortenza Advanced is an on-seed application of Fortenza Seed Treatment insecticide and Rascendo^® Seed Treatment insecticide. Helix Saltro^® is an on-seed application of Helix Vibrance^® seed treatment insecticide/fungicide and Saltro^® seed treatment fungicide. ADEPIDYN^®, Fortenza^®, Helix^®, Rascendo^®, Saltro^®, Vibrance^® and the Syngenta logo are trademarks of a Syngenta Group Company. © 2021.