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Barley Yellow Dwarf Virus (BYDV) in Grass Seed Production
OSU HAREC Grass Seed Field Day
Jordan Eggers
Symptoms:
• Stunting of plants
• Yellowing of leaf tips or yellow uneven blotches on leaves
• Some leaves may have purple or reddish coloration
• Leaves may become burnt or necrotic at the leaf tips later in the season
• Symptoms can sometimes be mistaken for nutrient deficiencies
Symptoms typically first arise in early spring of fall planted wheat or grass. Most severe
infections occur in early planted wheat that did not have an insecticide seed treatment. Later
plantings can also become infected especially if insecticides are not used AND temperatures
remain warm into late fall (November or December). Lack of aphid killing frosts in October and
November the past couple of years has lead to more severe BYDV infections. Additionally the
cooler, wetter springs has encouraged symptom development. Young plants are more
susceptible to infection therefore avoiding the virus or protecting against virus spread early in the
plant life cycle is important.
BYDV life cycle:
Transmitted by aphids
1. Aphid feeds on infected plants, virus moves through and is retained by the aphid
2. Aphid moves to an non-infected plant and begins feeding, can be long or short distances
3. Virus is present in aphid saliva, as aphid feeds it expels some saliva and the virus along
with it.
4. Offspring produced on infected plants can pick up the virus then spread to adjacent
plants.
5. Once infected, perennial grasses remain infected and symptoms can return each year.
Subgroup I
• MAV- A less severe strain carried by aphids (Grain aphid, Sitobion avenae),
• SGV – carried by Schizaphis graminum
• PAV - A less severe strain carried by aphids (bird-cherry aphid, Rhopalosiphum padi,
grain aphid, S. avenae, and others including Rose-grain aphid, Metopolophium
dirhodum).
Subgroup II
• Also known as Cereal Yellow Dwarf Virus
• RPV - the most severe strain, carried by aphids (Bird-cherry aphid, Rhopalosiphum padi),
• RMV (Rhopalosiphum maidis)
Subgroup I are the most commonly found strains in the Columbia Basin. From recent BYDV
wheat surveys the most frequently found strains are SGV and MAV. The PAV strain has been
detected but seems to be rare. Recent tests have not detected the Subgroup II strains in the
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Columbia Basin; however they may be present at very low levels. The OSU HAREC Plant
Pathology Lab has had Kentucky bluegrass plants test positive for BYDV.
Hosts:
Over 100 monocotyledonous species are susceptible to BYDV infection, including:
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Creeping bent grass
Oats
Broam
Orchard grass
Quack grass
Meadow fescue
Barley
Annual rye grass
Perennial ryegrass
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Timothy
Annual bluegrass
Kentucky bluegrass
Rough bluegrass
Rye
Wheat
Durum wheat
Corn
Impacts on Grass Seed Production:
• Can infect many common grasses
• Can cause stunting
• Studies have shown that BYDV infected grass can result in decreased or increased
foliage dry weight depending on virus strain and host species and cultivar.
• Research shows rye grass roots are negatively affected by BYDV even in cultivars with
increased shoot growth
• Little information on impacts on seed yield
• Grass fields may act as reservoir for virus, could impact adjacent new grass planting
Control:
• Manage grassy weeds, grass/grain volunteers in wheat and grass fields.
• Remove green bridge plants well ahead of planting, at least two weeks is ideal
• If there is heavy aphid pressure, consider aphid control especially during the first months
of growth. Be aware of warm temperatures late into the fall.
• Maintain proper soil moisture and fertility
If you suspect BYDV is present in you field contact your local Extension agent or contact the
OSU HAREC Plant Pathology Lab by calling Jordan Eggers at 541-567-8321 or by E-mail
[email protected]. The OSU HAREC Plant Pathology Lab can test plants and
aphids for the presence of barley yellow dwarf virus.
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Figure 1. BYDV infected wheat. Note the yellow and purple coloration at the leaf tip.
Figure 2. BYDV infected wheat (right) next to healthy wheat (left).
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Figure 3. BYDV infected perennial ryegrass. Arrows highlight symptomatic leaves
Photo by C. M. Ocamb, 2007
Figure 4. Circular patches of BYDV infected perennial ryegrass.
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Photo by C. M. Ocamb, 2007