"Jim W" wrote in message
Only a search for DIPLOCARPON ROSAE Sodium Bicorbonate on the web brought up plenty for me.. Although some were
*also* refs to the powdery
mildew. The other thing to do is to use the Chemical symbol formula so you'd search for:
DIPLOCARPON ROSAE NaHCO3
Although in this case google found that too specific (only 4 hits!)

The trick with blackspot seems to be addition of an oil and or potassium bicarbonate. Neem oil is also mentioned.
The basis of most of these bicarbonate controls is that they upset the pH balance enough to prevent the pest
functioning.
Incidentally the mildew experiment is one I repeated at University.. My results were inconclusive!-))

http://www.herts.ac.uk/natsci/Env/Fu...spot/home.html
Most interesting although out of date (2 years).. It only compounds my feelings as an organic supporter NEVER to
purchase cut flowers again!-)

Useful stuff sodium bicarb

Hmm.............looks like something individuals could usefully pursue without research funding - just so long as you
don't tell anybody you're using Bicarb for an off label purpose ;~))
It's difficult to imagine getting worse control than is currently available with the current domestic fungicides.

Rod.