This is one I haven’t seen before.
I had a 15 gal “Alampur Baneshan” mango that started showing symptoms of “Black Death” referenced above. The tree had just flowered so I wanted to try to avoid cutting it back so I sprayed and drenched it with sulfur instead. I
A few days later, it was clear that the sulfur wasn’t effective as the flowers were now wilting and the black area had spread to other branches. I did what I should have done initially and cut back the tree until there was no black visible, which only left me with a couple of inches above the graft.
I removed it from the pot to check its roots and to my surprise, I didn’t find a soggy mess. Instead, what I found was that the medium that was used when it was up-potted from a 7 to a 15 gallon, had been colonized by mycelium, creating a hard outer layer that the roots were not growing into (there were a few roots that got through, but not fibrous). I removed the encrusted outer layer and got down to healthy roots, which brought me back to a 7-gallon size rootball, and I planted it.
Has anyone ever seen this before? I’m guessing the roots were deprived of oxygen by being encased in that mycelium but I had always heard that it’s beneficial to roots, thoughts?
I have some citrus that needs to be potted up, would you use that mycelium-colonized medium (looks like pine bark and sawdust) at a diluted ratio, or should I just spread it like mulch over an in-ground tree?