USA
July 2014
Source: On Solid Ground, Washington State University
Cabbage seed infected with the black leg fungus.
Vegetable and oilseed growers are advised to take extra precautions after outbreaks of three fungal diseases in Pacific Northwest crops were recently found, said plant pathologist Lindsey du Toit.
For preventative measures and related information about the outbreaks on vegetables and oilseeds, view the newly released reports on black leg, light leaf spot, and white leaf spot by plant pathologists Cindy Ocamb, Oregon State University, and du Toit, Washington State University.
While only five Washington counties have quarantines for black leg, the most serious of the three, du Toit said all growers across the region should only use certified seed that tests negative for black leg in the coming growing seasons.
Black leg can be a significant problem in fall- or spring-sown plantings of broccoli, brussels sprouts, cabbage, collard, kale, rutabaga, mustard, canola and rape. The Pacific Northwest has particularly favorable environmental conditions for this disease, du Toit said.
The most recent outbreaks of all three fungal diseases occurred in Oregon’s Willamette Valley in early spring 2014. In the 1970s, outbreaks that nearly devastated the brassica seed industry in the eastern United States were tied back to the Pacific Northwest.
Visit the Pacific Northwest Vegetable Extension Group website for more information about the diseases. See the Extension publication Production of Brassica Seed Crops in Washington State for more on why black leg and other crucifer diseases have raised concerns about the need for additional quarantines.
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