Sooty blotch and fly speck are two distinct diseases of apple, but usually occur together.
- The fungi cause a discolouration or blemish on near-mature fruit in the orchard.
- The blemish is superficial and downgrades the fruit and hence reduces the market value or saleability of the fruit.
- In the UK the diseases occur sporadically in conventionally sprayed orchards, usually associated with wet summers and shady orchards.
- However, the diseases are becoming of greater significance with the increased production of fruit with reduced fungicide inputs in summer and of organic production, where losses can be high.