Dry Bean Anthracnose

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Dry Bean Anthracnose
Colletotrichum lindemuthianum
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Race composition

• Michigan 7 and 73 in 1993,
• 65 (Epsilon) in 1996,
• Ontario 23 (Delta) and 55 (Lambda) in 1979
• 65 (Epsilon) in 1984
• 89 (Alpha-Brazil) in 1994
• Manitoba 89 (Alpha-Brazil) in 2000
• North Dakota ???

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Epidemiology

• Conidia spread by water or rain splash
• Effective spore traveling up to 4.6 meters per
• rainstorm of 10 mm or more
• Lesions appear 3 to 7 days later

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Epidemiology

• Optimum temperature 55-79oF
• Fungus stops growing at 90oF
• Requires 10 hours of relative humidity gt92
• or free moisture for spore germination

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Survival

• Under the seed coat as dormant mycelium up to
• five years if stored at 4oC
• On plant debris less than one year (Ontario
• conditions. Up to two years (New York state
• conditions)
• Significantly less disease in moldboard than in
  No-till

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Control

• Two to three year crop rotation
• Avoid planting in areas adjacent to fields that
• had beans the previous season
• Use certified anthracnose-free seed
• DCT (Diazinon, Captan, and Topsin) seed
• treatment is only 95-97 effective
• Do not enter fields when plants are wet

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Control

• Variety recommendation will depend on
• the race present in the state.
• Navy Envoy and Newport (7, 73, 89)
• Vista (7, 89)
• Fleetwood (73, 89)
• Kidney Most of them (73, 89)
• Foxfire (susceptible to all)
• Pinto Most are susceptible
• Maverick (7)

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Due to small size of seed sampling, sampling
procedure is very important
Michigan grow-out test

• Samples of 400 seeds each
• Planted in large petri dishes
• Let grow until etiolation
• Evaluate for symptoms and grow in agar if needed