Sincere thanks for the responses to my Pioneer Mac post.
Mark Evans _____ From: [email protected] [mailto:[email protected]] On Behalf Of Matt Stasiak Sent: Friday, April 09, 2010 2:57 PM To: [email protected] Subject: Re: Apple-Crop: sickness in the Pioneer Mac block Mike, To add my two cents, we have had an on again off again problem with Lucostoma (Cytosopora) canker on McIntosh here at the Peninsular Research Station on both RedMax and Marshall, not yet on Pioneer. At least 4 blocks of various ages (Redmax/M26 20 yrs, Marshall/M26 10 yrs) showed symptoms. It even moved to an Empire/M26 block adjacent to one of the McIntosh blocks, but did not spread as quickly. Your description of symptoms, leaves hanging on through winter and major limb and leader die back sounds similar to what we saw. We have also seen greater symptom expression after cool wet extended falls. Our pathology lab did not always have success in isolating the causal agent and would often only find secondary fungi like Alteraria in samples. Lucostoma is apparently a week pathogen, but can enter trough wounds such as pruning cuts and branch stubs. We had the best luck isolating that fungus right around budbreak or late in the season around harvest. Diane Brown, a former MS student of Dr. Patt McMmanus UW Pathology, dabble with it a few years back, she had trouble isolating it from cankers. If I remember right, her IDs were mostly from fruiting bodies that yielded spores. But only a subset of the cankers had fruiting bodies, at least at any given time. She also only had limited success trying to inoculate health trees as part of here research. Matt J. Stasiak, Researcher University of Wisconsin - Madison Peninsular Agricultural Research Station 4312 Hwy 42 Sturgeon Bay, WI 54235-9620 Phone: 920-743-5406 Fax: 920-743-1080 cell: 920-559-0529 e-mail: [email protected] http://www.cals.wisc.edu/ars/peninsular/
