I agree with Kari’s analysis. Sounds like Marssonina. Bring or send some up if you’d like.
Dan — Daniel R. Cooley, Professor of Plant Pathology Stockbridge School of Agriculture 418 Paige Lab 161 Holdsworth Way University of Massachusetts, Amherst, MA 01003 Office Phone: 413-577-3803 | Cell: 413-531-3383 > On Oct 9, 2018, at 7:52 PM, David Kollas <kollasorchar...@gmail.com> wrote: > > Dan, Brian, Kari, Mo, and others: > > Having read your comments and links, I looked more closely at my > symptoms. I was wrong about its association with yellow delicious breeding. > I can find it in Macoun, Empire, and many others. The symptom common to all > that I looked at with magnifying > glass was scattered dark blackish raised dots in the live or dead “spot” that > often retains its green color after surrounding areas have > yellowed. I did not find any affected leaves that exhibited the concentric > bands noted in the 2012 blog, with click-enlarging photograph, by Dave > Rosenberger on Glomerella leaf spot. Therefore I conclude it is not > Glomerella infection. If it is Marssonina leaf spot, I would > not expect it to have survived all the captan sprays I have administered. > Sooty Blotch and Flyspeck, in spite of all the favorable > conditions for those diseases, are rare here at this time. I suppose it > could have a physiological cause that made areas of the leaves > susceptible to opportunist fungi, and some petri dish work in a lab might > isolate and identify those raised black dots. It is discouraging > to loose the leaves before harvest, not knowing why, nor what could have been > done to avoid it, > > David Kollas > > >> > > _______________________________________________ > apple-crop mailing list > firstname.lastname@example.org > http://virtualorchard.net/mailman/listinfo/apple-crop
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