Thanks for a very useful service you are providing.
I have an ongoing problem with rust on the spring onions. It may have come
through some infected bean seed or from the Yorkshire fog on the top
paddock. I've tried milk unsuccessfully (it's good for powdery mildew
control on the courgettes). There is seemingly no difference between beds
that have been maintained weedfree and other weedy beds. A pretty radical
approach discovered by accident is to mow the infected crop and let it
grow back! Amazingly it grows back totally clean!!! It would be nice however to
find a slightly less brutal method!
Rusts can be easily identified by the many orange or red pustules on leaves or stems which break open and release masses of spores.
One recipe worth trying is the following:
A heaped tablespoon of wood ash is stirred vigorously into a litre of water, left to stand overnight, strained and mixed with a cup of sour milk or buttermilk. Before spraying the mixture is diluted 3 times with water, but the strength of the solution should be checked by a trial on a small area of plants to ascertain the most effective dilution.
Cheers , Holger