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Type: Diseases

Chocolate spot (Botrytis fabae)

As the name suggests, this fungus (and, less commonly, its relative Botrytis cinerea) causes small red/brown spots on leaves and streaks on stems. The disease progresses rapidly in damp conditions, when the spots enlarge and spores are released, spreading the infection to other plants. In serious cases, the spots merge and darken, and may cause stems to collapse and even kill the plant.


  • Red/brown brown spots, sometimes with a white/grey centre as they expand, on all parts of the plant
  • Shrivelled and dropped leaves and flowers
  • In severe cases, collapsed stems

Prevention & control

  • Good crop rotation, removing crop residues. Note that autumn-sown beans may help the disease to overwinter
  • Autumn-sown crops are more susceptible as are those grown on nutrient-poor soils
  • Avoid overcrowding and weed growth as this fungal disease thrives in humid conditions
  • Destroy affected plants but only after harvest as the beans are usually still edible even if the pods are unsightly
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