Diseases of Faba Beans

Photo: Howard

Picture description
Bold chocolate spots.

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Management strategy

Ascochyta Leaf and Pod Spot.
Ascochyta fabae f.sp. fabae

What to look for?

Photo: Zimmer	Picture description Chocolate spots on pods and leaves.	Photo: Kharbanda	Picture description Tan to blackish lesion which produces typical botrytis sporulation (i.e. gray mold).
. Photo: Kharbanda	. Picture description Seed borne phase of chocolate spot.

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Management strategy
Use disease free seed and follow a 3 - 4 year crop rotation.

Mosaic.
Bean Yellow Mosaic Virus

What to look for?
Seed-borne from trace to 5% in faba bean. In areas of high aphid activity, a large percentage of this aphid-stylet borne virus will infect the crop, even up to 100%. Yield losses result but only 2-5% of the seed will subsequently carry the virus.

Photo: Evans

Picture description
Typical mosaic virus.

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Management strategies
Use virus-free seed if at all possible.

Powdery Mildew.
Microsphaera penicillate var. ludens

What to look for?

Photo: Rashid/Bernier

Picture description
Shows up very late in the season on faba beans, sometimes only on individual plants.

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Management strategies
Not really a disease problem.

Powdery Mildew Frequently Asked Questions

Rust.
Uromyces viciae - fabae

What to look for?
Not generally a problem disease in Canada. The fungus is seed-borne and has 5 spore stages. Some strains of this rust can attack peas and vetches.

Photo: Morrall

Picture description
Rusted leaf.

Photo: Rashid/Bernier

Picture description
Rust on the bean pods.

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Management strategy

Seedling Blight.
Rhizoctonia solani

What to look for?
Rhizoctonia may cause some damage in cold dry or cold wet springs. Stand density is not usually seriously affected.

Photo: Kharbanda

Picture description
Rhizoctonia lesions.

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What to look for?
A pythium type damping off fungus that has been isolated from faba beans in Manitoba.

Aphanomyces euteiches

Photo: Rashid/Bernier

Picture description
Seedling blight.

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Management strategy

Root Rot.
Fusarium sp. Rhizoctonia solani

What to look for?
Fusarium sp. are sometimes found alongside Rhizoctonia infections in seedling stands.

Photo: Kharbanda

Picture description
Stem and root rot.

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Management strategy

Sclerotinia Stem Rot.
Sclerotinia sclerotiorum

What to look for?
Found very occasionally in faba beans. Not really a disease problem.

Photo: Platford

Picture description
Sclerotinia infection.

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Management strategy

Heat Canker.
Non-parasitic

What to look for?
Collar damage can occur with rapid seedling emergence, in hot sandy type soils.

Photo: Rashid/Bernier

Picture description
Collar injury.

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Management strategy

Herbicide Injury.
Picloram/soil persistent

What to look for?
Faba beans are sensitive to less than 1/2 part per billion of this soil persistent herbicide. Faba beans may easily pick up Picloram that was applied as a spot treatment to soils as much as 40 years earlier. A half ounce per acre of Picloram for weed control in cereals will show up in faba beans two years or more after application.

Photo: Rashid/Bernier

Picture description
Severe leaf distortion.

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Management strategy
Avoid Picloram use in a faba bean rotation.

Photographs and information assembled and prepared for ARD by Dr. Ieaun R. Evans Agri-Trend Agrology Ltd.

Diseases of Faba Beans

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