Topic: Onion rot

[busy_lizzie]

Have just been over to my plot, and noticed that two rows of my onions had very yellow bottom leaves. Pulled some up to see the root was practically not existant and there was a slight white fungus looking material on them. Is this onion rot? it is my first year growing onions as my husband was the onion expert, and as many of you will know he died in February, so I thought I would carry on myself. We are on a four year rotation with our vegetables, so I would be disappointed if it is onion rot. I have pulled the two rows up that are affected, but the rest look okay. Can anyone give me some advice? I had 90 sturon and about 30 red onions. Thanks if you can  help. busy_lizzie

[RenishawPhil]

Sounds like onion rot to me :( all you can do is give them a miss for a while on that patch

[steve1967]

Hi Lizzie

This does sound like white rot. I have the same problem on my plot. This year hasn't been as bad due to the dry weather. I do rotate as you do. But its similar to clubroot once it gets a hold. Will take several years to go. I keep perservering and planting far more than I need in the hope I get a reasonable crop. This year from my Japenese onions I have lost 4 to white rot as opposed to last year where I lost 75% of the crop. So far with my spring crop I have noticed half a dozen with signs of rot. I have left them in place in the hope that the organism responsible will stay with that onion rather than spread.

[davyw1]

Your problem is the onion rot has activated and will as long as you provide the food which is the onion or garlic. If you walk on any activated onion rot or use the same tools without sterilizing them you will spread it.
There is variations on how long it lasts from seven to fourteen years, so you can not grow any onions within that time where the rot exists.
What you can try is to decide where your onion bed is going to be next year and spread garlic powder over it. (all  of it). This will only work if it is hot and humid as this is what activates the rot so when it does activate it has nothing to live off and dies.

[Tee Gee]

Dose it look like this ?

http://www.thegardenersalmanac.co.uk/Data/Onion%20White%20rot/Onion%20-%20White%20Rot.htm

[busy_lizzie]

Hi Tee Gee, Unfortunately it does, though the white fuzz is not quite as bad as your picture. If I pull all the infected ones up, what are the chances of my saving the rest? The other rows look quite healthy. Also what should I sterilise my tools with? I really have only used an onion hoe on that area. I also have leeks planted there too, could they be affected? It is so disappointing as it has never happened before in the ten years I have had my plot. Thanks to everybody who has replied. I really appreciate it. busy_lizzie

[davyw1]

Just stand them in a mix of jeys fluid.
As you say never had it in before but it only takes one person who does have it to walk on your garden, its as easy as that

[small]

Sorry to hear about the rot, isn't it disappointing when a crop gets so close. You may well get away with it for some of this year's onions, but in my experience it spreads so next year you will lose more, and so on.
I read on here last year about a method of waking up the rot spores by watering on mushed up garlic in the autumn,  the same principle as Davy and the garlic powder. I did this on a dedicated patch, have taken extreme care not to reinfect from other areas of the garden, and so far it looks to have worked - I have garlic, shallots, onions and leeks all looking good. I was going to report back here at harvest time, fingers crossed it has worked...all the best for your crop, and well done for carrying on as you have done.

[Ellen K]

This year, on our site, we have the Allium Leaf Miner and you can see the twisyed top growth and when you pull the onion up, it has secondary white rot.  I have pulled up about 1/3 of my onions (they are not going to make anything) but going round the site, you can see a lot of people aren't bothering.

My view is that we all have a bit of club root and onion rot and a million other diseases in the soil, esp if your site has been allotments for decades like most,  and what you have to do is keep it from getting too much of a hold by pulling out diseased plants and rigorous crop rotation.

So dont despair BL, your onion growing days aren't over yet.  And what small and davy suggested is definitely worth a go if you can find a tub of horse garlic powder.

[davyw1]

The best place to get a tin of garlic powder is a pet shop and you want Equine Garlic powder not the granuales

[bluecar]

Hello Davyw1.

Is the best time to spread the powder now as soon as you are aware of the problem? I've just lifted 3 onions which have a white fungus on and no root. I suspect a few more have the problem. Is it just scattered or watered in?.

Regards

Bluecar

[macmac]

http://www.amazon.co.uk/Garlic-Powder-Equimins-Nutrition-Supplements/dp/B008B5R612/ref=sr_1_10?ie=UTF8&qid=1373295860&sr=8-10&keywords=garlic+powder+for+horses

'Have just ordered this but not sure when and how best to use it so any advice please 

[davyw1]

You do not put it where your present onions are, you have to spread it on where your onions are going next year.
How it works is when you put the garlic on top of the soil and the conditions are right the white rot activates thinking there is food for it as there is nothing for it to feed off it dies.
You need to watch the weather forcast for when its going to be hot, humed and damp thats the conditions the rot needs to activate.
To put the powder on i just used my hand making sure i covered every bit of soil, an after thought was the long haired generals flour sieve but didnt fancy getting caught sneeking it out.

[macmac]

Thanks davyw1, we've always loved growing onions but had to give up in recent years so will definitely give this a go.

[cornykev]

It happened to mine a few years ago and got worse the next, I lifted all the onions and binned 85/90% of them. I did the onions in a bucket trick and watered in the liquid but I still planted on raised beds the next year and they've been fine since, touch wood. I will water in the garlic powder mentioned when the ground for next years onions is clear of crops and continue every year after.   

[davyw1]

It happened to mine a few years ago and got worse the next, I lifted all the onions and binned 85/90% of them. I did the onions in a bucket trick and watered in the liquid but I still planted on raised beds the next year and they've been fine since, touch wood. I will water in the garlic powder mentioned when the ground for next years onions is clear of crops and continue every year after.   

Kev, just about watering in, i didnt try that i just put the powder on and left things to nature, i think if if you are going to try that way just a light sprinkling so not to wash the powder in

[bluecar]

Thanks for the information.

I'll try the garlic powder. I use a three year rotation so that should also help a bit, but I assume I'm best sterilising any tools once I've used them on the affected bed.

Regards

Bluecar

[cornykev]

Cheers Davey, I did water it in when I left onions to soak in the water, but I will sprinkle it in when I use the garlic powder.     

[busy_lizzie]

Thanks for the tip about garlic powder, and instructions, I will certainly spread it on my next bed. So far I havent had any more onions going yellow, so I am crossing my fingers I will at least have some sort of crop this year. busy_lizzie

[chriscross1966]

Thanks for the information.

I'll try the garlic powder. I use a three year rotation so that should also help a bit, but I assume I'm best sterilising any tools once I've used them on the affected bed.

Regards

Bluecar

Affraid three years won't touch white rot, the general reckoning is that to be sure you'll need to leave the ground for 15 years before it sees another allium.... I tried putting garlic powder in last year where my  onions are this and I've got a lot fo rot showing, lost some of the overwintering tough-balls.... Looks like I'll have to build a raised bed for onions....