Q.
Can you tell me what this is on one of our peach trees? The leaves are
developing black spots on the margins.
Can you tell me what this is on one of our peach trees? The leaves are
developing black spots on the margins.
A.
I am looking at your picture now of the peach leaf. It was hard to see what the
problem might be with only one picture and that picture was low resolution.
I am looking at your picture now of the peach leaf. It was hard to see what the
problem might be with only one picture and that picture was low resolution.
What I saw was one leaf inside the
canopy in some shade with some black spots developing on the leaf margins. I
couldn’t be certain but it looked like there was a yellow halo around the black
spots on the margins. I don’t know if this is typical of all the leaves or just
the leaves in the shade.
canopy in some shade with some black spots developing on the leaf margins. I
couldn’t be certain but it looked like there was a yellow halo around the black
spots on the margins. I don’t know if this is typical of all the leaves or just
the leaves in the shade.
For me there were two possibilities;
irrigation or a disease called shot hole fungus or Coryneum Blight. If it was
over the entire canopy and it involves leaves in full sunlight then I would
tend to think it was irrigation related.
irrigation or a disease called shot hole fungus or Coryneum Blight. If it was
over the entire canopy and it involves leaves in full sunlight then I would
tend to think it was irrigation related.
It usually occurs if the tree is not
getting enough water at the time of an irrigation or if you waited too long
between irrigations. If the tree has gotten considerably larger in the last two
years than I would add any emitter or two to the irrigation of the tree.
getting enough water at the time of an irrigation or if you waited too long
between irrigations. If the tree has gotten considerably larger in the last two
years than I would add any emitter or two to the irrigation of the tree.
I would also mulch the surface of the
soil to conserve water and reduce water stress.
soil to conserve water and reduce water stress.
If this is Coryneum Blight then you
would spray the tree with a copper-based fungicide such as Bordeaux mixture
immediately when the leaves fall from the tree this early winter. You would
follow up with the spray in the spring as the leaves are coming out and new
growth is emerging but after blooming has finished.
would spray the tree with a copper-based fungicide such as Bordeaux mixture
immediately when the leaves fall from the tree this early winter. You would
follow up with the spray in the spring as the leaves are coming out and new
growth is emerging but after blooming has finished.