sherwindu wrote:
Many references tell me not to mix dormant oil with any sulfur compounds. They
recommend a 30 day interval after doing the dormant oil.

I find that, no matter what else I do, I will still get both leaf curl
and brown rot unless I use a dormant spray on my peach tree. I use a
mixture of dormant oil and copper sulfate, spraying once right after
pruning and once again as the flower buds start to show color (just
before they open).

Actually, I use a commercial dormant spray that already has the oil and
copper sulfate combined. I understand that this mixture is not
available any more, but I have seen it in separate bottles -- oil in one
and copper sulfate in the other -- packaged together with instructions
on how to mix them.

Copper sulfate is a fungicide that is usually classed as a copper
compound, not as a sulfur compound.

--
David E. Ross
Climate: California Mediterranean
Sunset Zone: 21 -- interior Santa Monica Mountains with some ocean
influence (USDA 10a, very close to Sunset Zone 19)
Gardening pages at http://www.rossde.com/garden/