Posted 27 August 2012. PMN Crop News.
Speckled Apples a Little More Rare in 2012
Source: University of Illinois at Urbana-Champaign Press Release. www.illinois.edu
Urbana-Champaign, Illinois (August 13, 2012)--Two fungi are often responsible for smudging/speckling on apples. The two diseases caused by these fungi (the culprits behind the smudging/speckling) are termed sooty blotch and flyspeck. Random smudging is caused by hundreds of small reproductive fruiting bodies resulting from the sooty blotch fungus. Circular patches of specks are caused by flyspeck. Both fungi overwinter on various types of plant material and spread to orchards as spores in May and June.
Both types of fungi need temperatures that are not much higher than 70 degrees. They also need humidity to be in the 90 percent range. Minus those conditions the fungi go dormant. During most seasons, they drop off during the summer and become active in Late August/early September. In 2012 - given a forecast that calls for continued dry weather - one would not be surprised if speclling/smudging tends to be more rare.
Regardless, sooty blotch and flyspeck are relatively minor diseases. The fungi attack only the skin of the apple and usually do not penetrate the fruit itself. Universities often simply recommend that the home gardener rub the fruit with a piece of material to remove the specks/smudges.