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Tomato, Buckeye Rot

Buckeye Rot on green tomato fruit

Phytophthora spp.

Buckeye Rot of tomato is caused by three species of Phytophthora: P. capsici, P. drechsleri, and P. nicotiana var. parasitica. Buckeye Rot almost always occurs on fruit that are in contact with the soil and can occur on green or ripe fruit.


The disease begins as small brown spots on fruit which grow in to large, round or oblong lesions with alternating concentric rings of light and dark brown discoloration. The lesions are firm, with smooth margins; but eventually become soft and decayed.

Life Cycle:

Buckeye Rot is most prevalent during warm, wet weather and is spread by surface water and splashing rains. Excess soil moisture favors infection. The disease is important wherever there is high humidity, warm temperatures, and abundant soil moisture. Different tomato producing regions may have different species involved.

Cultural Controls & Prevention:

  • Avoid fields with heavy, poorly drained soils.
  • Reduce soil compaction.
  • Plant in raised beds.
  • Avoid low areas of fields.
  • Rotate to non-solanaceous crops.
  • Stake and/or mulch plants to reduce contact with soil.

Chemical Controls & Pesticides:

For Current information on disease recommendations ins specific crops including information on chemical control & pesticide management, please visit the New England Vegetable Management Guide website.

Crops that are affected by this disease:

Last Updated: 
January 2013

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