WSU Extension


Strawberry : Gray mold
(revision date: 5/6/2014)

Fruit rot is caused by a fungus which attacks many plants. Strawberry leaves, stems, flowers, and buds may be attacked, but the worst damage is to the fruit. The rot typically begins as a brownish, water-soaked spot on any portion of the fruit. Infection may occur at the stem end of the fruit, or where the fruit contacts diseased plant parts or the ground. The infection spreads quickly throughout the fruit. Infected berries often develop a powdery coating of brownish-gray fungal growth. Berries infected in the field may not show symptoms until they are in storage, where they quickly rot. Cool temperatures and moist conditions favor disease development. Spores are spread by wind and splashing water. The fungus overwinters in diseased plant debris.
Management Options

Non-Chemical Management
  • Plant varieties which show resistance to gray mold. Among these are 'Shuksan', 'Totem', and others with erect fruiting habits.
  • Space plantings to provide good air circulation and reduce humidity.
  • Avoid overhead watering.
  • Keep berries from contact with soil. Plant in raised beds or use straw mulch beneath plants to help prevent fruit infection.
  • Provide proper culture. Excess fertilizer promotes dense, slow-drying foliage which may be more susceptible to disease problems.
  • Pick off diseased fruit and clean up plant debris. Destroy or discard (do not compost) diseased materials.
Select non-chemical management options as your first choice!

Chemical Management

None recommended

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Caption: Botrytis gray mold on strawberry
Photo by: R.S. Byther
Caption: Botrytis gray mold on strawberry
Photo by: R.S. Byther