Onion white rot

[Geoff TurnerParticipant]

My multisown onions have been struck by the dreaded white rot. This is on my new allotment: onions were fine last year but white rot has shown up after rotating to the next quadrant (4-year rotation plan at present). Odd thing is that not all of the onions have fallen over. Started about 4 weeks ago when a couple of clumps showed the signs – pulled them (no resistance) and they had the fluffy fungus. I lifted my garlic which was growing alongside and a couple of them seemed to have the fluffy fungus growth. Since then, odd clumps of onions have started to get yellowing leaves and loose in the soil – no more fluffy fungus, perhaps because I’m lifting them at first symptoms? 3/4 of the onions are still growing happily -so far. (this is different to my previous experience of white rot in my back garden, where the whole lot fell over at once) RHS says white rot doesn’t like temperatures over 20C I see; the weather has been hot but not sure the soil is likely to get this warm. I’m in Tyne & Wear.
So my questions concern how white rot spreads. I’m hoping someone will know. There’s much talk around no-dig about fungal networks; does this include white rot? Is the rest of my crop doomed? If I try to grow onions next year in the next quadrant of my rotation, what are the chances of failure due to white rot? Should I give up or try again?

[StringfellowParticipant]

Geoff, my understanding is that white rot is spread physically i.e. if you dug up a chunk of infected soil and spread it in an unaffected area, you will increase it. Don’t do that though 😉

I’ve had trouble with it, but it doesn’t put me off growing onions because:

1) I cleared an area of our plot (weeds, rubbish) that was unused for many years; this is the main onion growing bed.
2) We harvest and then fry for about ten minutes, any infected onions, followed by freezing. The yield is less but we still gain something. Any trimmings go in the landfill bin, not the green composting.
3) I’m going to try “Golden Bear” next year as it, allegedly, has white rot resistance!

Hope this cheers you up/ increases your options a bit, as it can be very disappointing to see your hard work and care end up in a failed crop. Cheers.

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