White rot

[bikermike]

Quick question, how bad is it for other alliums?
i think I may have some level of it over the whole plot, and I can't avoid it, so it's about management. I have grown leeks and onions happily before.

I'll garlic water the known areas.

[burnie]

This is what the RHS have to say.....................Onion white rot / RHS Gardening

[Mr Bones]

Our garlic, elephant garlic and onions are affected (including spring onions) but leeks only on rare occasions.

[quanglewangle]

We sometimes get small anounts of white fungus around base of onions but doesn't seem to affect their growth, ripening, or keeping. I just wipe it off when harvesting. Maybe a different pathogen that just happens to be white.

We only grow autumn started Japanese sets - not claiming that makes a difference.

[quanglewangle]

Our garlic, elephant garlic and onions are affected (including spring onions) but leeks only on rare occasions.

When you say affected do you mean devastated, uneatable, or they have it but are still more or less ok?

[Mr Bones]

When you say affected do you mean devastated, uneatable, or they have it but are still more or less ok?

The underground parts are covered in white fungal growth, enough to make the leaves die off. At that point it's visible from above and a gentle tug shows the roots have already been eaten through. Sometimes the plant is still edible, sometimes not.

[ameno]

We sometimes get small anounts of white fungus around base of onions but doesn't seem to affect their growth, ripening, or keeping. I just wipe it off when harvesting. Maybe a different pathogen that just happens to be white.

We only grow autumn started Japanese sets - not claiming that makes a difference.

Ever since I started growing onions at my allotment I've noticed that around 10% succumb to some sort of mould around this time of year, the roots rotting and causing the leaves to wither, and if left too long the bulb will start to rot, too, but I don't think it's white rot.
For starters, it's doesn't seem aggressive enough. It doesn't spread through the onion all that quickly, and all the infected onions have always still been at least 80% edible. Secondly, the white fungal growth is wispy and sparse, rather than dense and slightly spongy as white rot fungal growth is. And I've also not once seen any of the black sclerotia that white rot is supposed to form.
There are other foot rots and base place rots that onions can be prone to, so I think in my case it's just one of those, rather than white rot.

[quanglewangle]

^^^^
My experience is similar to that of ameno.

I wonder if there is something in the way we grow our onions that, although the ground is infected, doesn't favour full blown development of the pathogen.
We:

• Grow autumn started onions
• Don't water them much after about May, although quite a bit before then
• May and June are often dry months are in West (compared with monsoon that comes with school holidays)
• Ripen them on greenhouse benches, not on soil.

Not advancing any of these as a cure but maybe looking for common threads among folks who can grow onions on ground that is infected but still get reasonable results.