Topic: Treatment for onion white rot

[George the Pigman]

Has anyone tried using sulphur powder to prevent/eliminate onion and garlic white rot? It's getting to be a big problem for me over the last few years.
The idea springs from an article I found http://scialert.net/fulltext/?doi=jm.2011.904.911

It should also make the onions more pungent as sulphur compounds are what give it its strong flavour and smell!

[BarriedaleNick]

Yes..

There is a thread somewhere about this - I think I may have even started it!  AH found it..  http://www.allotments4all.co.uk/smf/index.php/topic,78156.msg792062.html#msg792062

I tried a small patch last year with great success but empirically it isn't significant as I need to replicate it this year.

I used garlic powder and liquidised onion and watered into my test bed. Previously the test bed had produced onions with white rot but not all were affected so I think it was a decent enough test.  I didn't get any rot at all - not a smidge.  However several fellow growers didn't get as much rot as previous so maybe it was a dry year or something else was affecting the amount of rot.  So not at all conclusive but well worth a shot.

[small]

I was delighted with my first year trial of mashed up garlic watered in, barely a sign of rot and a really good crop of onions, shallots and leeks. Did the same again for last year, and lost at least half the crop, had to pull the rest early and freeze rather than store the usual way......I don't think I did anything differently, but I couldn't bear risking the disappointment again so I'm afraid for me it's Tesco from now on. Good luck if you decide to give it a try, let us know how you go on.

[BarriedaleNick]

I think you need to aware of conditions when applying it - soil temp must be right and you have to water in really well.  I did a bed last September for planting out this year so we will see - in a few months!  I'm not totally convinced as yet.

[Pescador]

Am I missing something here?
George asked a question about using sulphur to control white rot.
The answers are about using garlic as a control method.

George, I will read that paper with interest as I have had to abandon all Alliums, and if sulphur promises to be a good bet then I'll give it a go this year. It's got to be cheaper than garlic granules!

[Pescador]

BarriedaleNick, What were the results of the treatment, how was this years crop?

[johhnyco15]

i was going to give up this autumn on onions untill last year i put in 3 rows of spring onions my dad had sown for me i had no room for them so i dragged three lines in the soil next to my large toms and literally chucked them in and forgot  about them july came and not one had any rot and they were the size of golf balls so i had a bottle of amillatox soaked the ground and put in my autumn onions if it dont work then im off to tescos too

[George the Pigman]

Well this year I have decided not to bother growing garlic due to the white rot problem and only use sets for onions instead of growing them from seed. The ones from seed were badly affected but I had a good crop of shallots that I grew from sets. It must be something to do with the fact that the ones from seed (and garlic bulbs) spend longer in the ground and so are more likely to be affected.
I haven't seen white rot on spring onions - perhaps its because they are a different type of onion from the other varieties?? Mind you I don't get good crops from them as they seem to grow very slowly with me!

[Vinlander]

Well this year I have decided not to bother growing garlic due to the white rot problem and only use sets for onions instead of growing them from seed. The ones from seed were badly affected but I had a good crop of shallots that I grew from sets.

Interesting - many people avoid onion sets because they think they are MORE likely to get white rot. It's the opinion of many experienced and competent growers too - I'd say a majority, and I know for a fact that if you dig out the failed sets as soon as a difference shows you find a lot that have died from white rot - and most of the time it happens so early that you can only conclude that they brought it with them.

I don't think the set-growers are very fussy businessmen - and those that are carefully producing a clean crop are probably among the ones charging absurd prices for them (as are 90% of the cowboys - and impossible to know if it's just the difference between lucky cowboys and unlucky ones).

Cheers.

[Vinlander]

Am I missing something here?
George asked a question about using sulphur to control white rot.
The answers are about using garlic as a control method.

Sulphur is a traditional method of controlling fungi (and mites) and has been around for centuries - if it was effective and economic (key issue) to use in the soil (where else?) to stop white rot I think we would all know already. It certainly makes onions taste stronger - not necessarily in the first year.

It is a fair point to revisit - but it's also fair to offer an alternative in this thread - especially if it is an relatively new and little-known technique that is gaining a very good reputation.

I must point out that a key factor was missing from the garlic/onion powder/mash method in this thread - it has to go on the bed for an entire season without onions or garlic (though there's nothing to say you can't get some other crop off the bed in the meantime).

I may have just missed it - but it is pointless without stressing it. I've even read that there's no problem mashing dodgy onions (unless you think the bed is clean anyway - seems unlikely) - because the whole point is that the fungus starves to death. I would certainly be happy putting a shop-bought 5kg bag of onions (for as little as £1.25) through the blender and using it in this way. You don't get much sulphur for £1.25 these days...

Cheers.