Blackleg disease strikes canola fields in Idaho

Blackleg has been confirmed in more than a dozen fields in northern Idaho canola between Moscow and Grangeville.

Blackleg disease strikes canola fields in Idaho

 

Blackleg has been confirmed in more than a dozen fields in northern Idaho canola between Moscow and Grangeville.

For updates and added help regarding the outbreak, the disease and what you can be doing to scout for blackleg, go online to smallgrains.wsu.edu/blackleg-confirmed-in-Idaho-canola-fields

Scouting recommendations from Extension resources advise the following procedures:

Wear rubber boots that are tall enough to cover your calf muscles whenever you enter a field since rubber can easily be disinfected with alcohol to prevent spreading the disease in or between fields.

If crop height is lower than boot tops, you only need to sterilize the boots when you leave each field and before you enter the next survey area.

When finishing scouting a field, scrape and wash off any soil adhering to the boots. Then, spray boots with 70% alcohol (ethyl alcohol is advised) after you have removed the soil. It is a good idea to keep spray bottles filled with alcohol in your vehicle.

If the canopy is higher than your boot tops, wear a Tyvek suit to cover your pants (and waist, chest and arms if the canopy is that tall). Spray the legs of the suit, or any part which may come into contact with the canopy, with alcohol after you exit the field.

Place a plastic tarp (or similar fabric that can be easily washed and sterilized) in the vehicle onto which boots can be placed each time after they have been sterilized, along with any other sampling and scouting equipment that should be sterilized before being placed on the tarp.

Keep clean shoes to wear when driving between fields, and make sure those shoes do not touch the soil or any other surface that might have come into contact with the blackleg pathogen. Transferring from the clean shoes into the boots may be tricky to avoid contamination (be sure not to wear clean shoes to walk over areas previously stepped on with the boots).

Wear latex gloves and put on a new pair for each field (or spray gloves thoroughly with the alcohol solution).

Put a trash container of some kind in the vehicle that is designed for discarded gloves, paper towels you might have used to wipe off soil, and anything else that potentially could be contaminated with the blackleg pathogen.

Key Points

• Blackleg disease is found in canola crops in Idaho.

• Other PNW states are checking for signs of disease.

• Precautions must be taken to control spread of disease.

At the end of each scouting trip, autoclave any waste material that could be contaminated with the pathogen.

Karen Sowers, Washington State University Extension oilseeds specialist, has been checking fields in Columbia, Whitman and Asotin counties, and may be reached at 509-396-5936. Researchers from Oregon State University are also looking for potential outbreaks.

Blackleg was also found in residue of a 2014 spring canola field on the southern Winona Butte east of Greencreek, Idaho. If you have any live canola or other brassicas, winterkilled canola residue, live cover crops or cover crop residue, 2014 spring Brassica residues (e.g., canola, mustard, camelina), or even brassica weed species in or near fields, take a few minutes to get a close-up look at the leaves and stems for any sign of blackleg.

The best defense is buying certified blackleg-free seed, selecting blackleg-resistant varieties, rotating crops (four years between brassica crops), and making sure there is seed treatment applied.

 

06152241.tif

BLACKLEG STRIKES: Disease lesions on this canola leaf show what growers are looking for in a Pacific Northwest outbreak.

This article published in the June, 2015 edition of WESTERN FARMER-STOCKMAN.

All rights reserved. Copyright Farm Progress Cos. 2015.

Seed Diseases

Crop Management

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