Tomato Diseases: Fruit

Most of the diseases or problems with the tomato fruit result from contact with the soil or sub-optimal growing conditions. Keeping the fruit off the ground, proper watering and adequate sunlight will prevent many of the problems listed below.

Disease/Problem Symptoms Management
Anthracnosefungus Colletotrichum coccodes
  • Small, slightly sunken water soaked circular spots.
  • Spots will become larger and darken in the center.
  • Copper sprays offer some resistance.
  • Remove lower 12 inches of leaves to avoid contact with soil.
  • Water the soil, not the leaves of the plants.
Bacterial Speck
  • Tiny raised, dark spots
  • Usually have a white border
  • Copper fungicide
Blossom End Rot
  • Dark brown/black spots at blossom end
  • Spots become larger as the fruit rots.
  • Attributed to low calcium during fruit set.
  • May be caused by high nitrogen fertilizer or uneven watering.
  • Remove affected fruit water regularly and deeply.
Buckeye Rot
  • Common in Southern states
  • Similar to blossom end rot in appearance but it occurs on green fruit.
  • Remove affected fruit and keep fruit from contact with the soil.
Gray Wall
  • Green fruits may have a gray cast or gray blotches.
  • Red fruit has green or brown areas on the inside of the fruit.
  • Make sure that the plants are in a sunny location and aren’t shaded.
  • Provide even waterings.
  • Fertilize as recommended.
  • Keep soil loose around the roots.