Newbie to the forum here - thanks to all for wonderful discourse and work!
Follow-up question for this topic: a high percentage of our orchard consists of semi-dwarfs (mostly M7) that were planted in the mid-80s, especially in our one upper (highest elevation) PYO block. Thusly we have many older trees, a high percentage of which have been colonized with black rot, especially in some of the weaker cultivars (i.e. traditional Golden Delicious and Gala). We don't see a high occurrence of FELS in this block, suprisingly, just the classic black rot on limb and trunk cankers. I've only noticed heavy colonization of FELS in our Honeycrisp, which is in a completely different block with younger/healthier trees, strangely.
More orchard background: Though we manage our farm with bio-diversity and ecosystem health first and foremost, we have mixed opinions on allopathic organic materials and are new to holistic sprays altogether. Michael recommends holistic trunk sprays to enhance health before infection (which I hope to implement starting this growing season), but I'm interested in hearing how holistic trunk/limb sprays can help lengthen an aging tree's life even after colonization by black rot. Has anyone had success/experience with this? We are about to lose our Golden Delicious altogether and don't have a planting ready to replace it. This will leave a gap in our PYO varieties for the "late-season" window unless I can nurse these trees along for a few more years...
Our current management for Frog Eye Leaf Spot/Black Rot: manage orchard for beneficial fungi on the orchard floor as much as possible; remove black rot cankers during winter pruning (chip small diameter wood back into the orchard soil and burn large diameter wood); maintain proper pruning for airflow. We receive the "Michael Phillips Badge of Fungal Honor" every year - lots of 'shrooms growing on the orchard floor.
We'd prefer to not use sulfur. Additionally, we cannot use copper as an allopathic measure because we graze our sheep through this block, and copper is incredibly toxic to sheep. We found this out the hard way when we fed hay grown by a neighbor who fertilizes with composted pig manure (pigs' bodies are very adept at eliminating copper, and so their manure has a high percentage). We lost several animals before figuring out the problem. Now we feed solely with hay grown from our own hay field (they also graze rotationaly throughout other parts of the farm).
Thoughts? We have begun being more aggressive at eliminating inoculum in the orchard--oh how it hurts to take down those trees!--but as of now this is our only strategy.
Addition after more thoroughly reading the wonderful thread on Anthracnose - would an application of Biodynamic tree paste on the trunks be worth a try?
Door Creek Orchard
Zone 5a in Wisconsin
Edited 1 time(s). Last edit at 02/14/2016 05:42PM by Liz Griffith.