Potash Application - Rust Preventative?

[VirginVegGrower]

I've just read that potash applied in April can help in the fight against rust. Now given that I always end up with rust on alliums somewhere, has anyone heard of this, carried it out, been successful?
Thanks in advance!

[bearded bloke]

According to Marshalls .........

Garlic responds well to potash, so if you have any available wood ash you can make use of it by digging it in to your soil,so if you have any available wood ash you can make use of it by digging it in to your soil

However .......

Rust disease – rusty spots form on the leaves, sometimes killing them off completely, often resulting in smaller bulbs size. This commonly happens when the growing garlic sits in damp soil for too long, it can also happens if grown in soil where either onions, garlic or leeks have been grown before. There isn’t a cure for rust disease, but if you see any leaves with rust-coloured spots on, remove them and throw them away to help prevent the rust from spreading. Don’t grow garlic, onions or leeks in areas that have been affected by rust - avoid these areas for 4 to 5 years as the spores can be active for years.

Taken from : How to Grow Garlic (Allium sativum) at Marshalls Seeds

[VirginVegGrower]

I rotate my groups on a four year plan. I have removed diseased foliage before. The soil is free draining and sandy. It's not just me that suffers up on that plot.
I may just throw it on anyhow.