[Jakell]

 A couple of my garlic plants seemed to be dying last week. I pulled them and discovered the roots and lower bulb  (and the surrounding bit of soil) were covered in a white fungus. Also one of my onions, the rest are in rude health. I wasn't too worried thinking I will deal with any fungus with sulphur when it shows itself.

 After reading up on white rot on the net I am now horrified, 8-18 years before your soil is clear again, cannot grow onion family until your soil is clear, no real solution, organic or not. Having prepared myself for the worst I looked at my alliums again this morning. Garlic is yellow tipped  so I pulled a few and discovered no rot at all, The onions are great with no yellow tips at all.

 My question is this... Is it possible to have some white rot (assuming that's what it is), but not enough to affect your whole crop, that a 3 year rotation should keep in check. or is it like potato blight ie a hint and it will do for the whole crop?

[Aunt Sally]

Oh yes it is quite possible.  I have it on my plot and lose about 20% of my crop to it.  The rest seem OK

Some pictures here

[Jakell]

Oh yes it is quite possible.  I have it on my plot and lose about 20% of my crop to it.  The rest seem OK

Some pictures here

 That is a relief, however 20% seems like a lot to me and I would be worried about it increasing . How many courses in your rotation? I can only fit three beds onto my plot  so it is three years max for me.

 Sorry about the duplication of the thread below

[Aunt Sally]

I working on a 3 year rotation at present but having said that I don't put the onions back in the same place in the bed when it comes round to the 3rd year again so it probably works out a lot longer.

[Jakell]

I working on a 3 year rotation at present but having said that I don't put the onions back in the same place in the bed when it comes round to the 3rd year again so it probably works out a lot longer.

 Actually that is the same with me. Alliums and brassicas different ends of the same bed, swapping end when they come around again. This is mainly to prevent clubroot, but it should work well for the onions too.
 You have to more creative when you only have three beds.

[upert]

surely not all white mouldy matter on the base of an onion is the dreaded white rot? can't it be a common or garden rot? yes, i've found some on a few of my onions. it doesn't look rotten at all, so here's hoping.

[Aunt Sally]

It probably is white rot 

[upert]

i think i had something like it last year and yet the plot was unworked before i took it on. for quite a while too. i can't seem to accept it's white rot. i'm in denial.

[Paul Plots]

OK - so now I know a bit more about rotten white rot. Useful.... thanks

I usually lose some onions to it each year.

"Next year", it says on my reminders list, "plant the onions on the new half-plot despite the soil being better suited for making pots and see what happens!" 

[themoog]

Been reading this with interests, as I discovered white rot on my garlic at the back of the bed but none on the over-wintering onions in the rows in front. I've got 5 year rotation (but tiny beds) so I'll see what happens. With any luck I might have managed to get some more space by then, as I'm not allowed more than a quarter plot until the waiting lists go down  .

I'm encouraged to hear that I don't have to consider the whole bed out-of-bounds though.

[Aunt Sally]

http://www.rhs.org.uk/advice/profiles0800/onion_rot.asp

It seems to sugest here that once it's in the soil it NEVER goes 

"If the infection is diagnosed do not grow susceptible plants in that area of the garden again."

[DavidT]

In the winter treat the area where onions/garlic and their ilk have grown, with Jeyes or Armillatox. Ideally, treat the ground with jeyes or armillatox. A month later, turn the soil over and treat again, Do this one more time, then leave the ground to the elements until planting time. Repeat yearly until the virus is gone.

[Aunt Sally]

It's a fungus rather than a virus David.

I am aware that these treatments have been used in the past but as the products are no longer permitted as soil treatments I'm afraid that these forums cannot endorse their use for white rot.

[Salmo]

What else do you kill with Jeyes or Armillatox? It does not discriminate between bad soil life and good and the soil ecosystem may get completely out of balance. It could even be why the white rod fungus has thrived.

Good garden hygiene is needed. Clear up plant waste, have a wide rotation, do not compost or dig in diseased material, clean your tools throughly ( a good use for Jeyes fliud).

A lot of the onion family are overwintered these days. I just wonder if the overwintered plants help to carry the fungus over from one season to the next?

[granjan]

Has anyone tried garlic spray or powder?  The idea is that you use either on ground in which you are growing anything but alliums.   The smell encourages the rot to grow.  Having no host plants, it kills or weaken the white rot. 

I've tried spraying this year as I have it on the allotment but thought I would try digging in powder next year in the spring.

Any thoughts :unsure