White rot in garlic

[bikermike]

Botheration!
I am 70% sure I've got it.
is there anything else that gives white gunk with black spots in it?

anyway, seperated out the affected and will store it seperately to the unnafected (and keep a careful eye on all of it).

so no alliums in that bed for 5 years (does it affect brassica?), and the off-cuts all disposed of away from tge compost. Can I use the scapes that have grown on the tops next year? (I wont plant any saved cloves)

Mike

[Nicos]

Can't really help, but there is some interesting info here about treatment.....

https://www.motherearthnews.com/orga...e-rot-zbcz1412

This scientific paper helps with ID and gives info as how to use garlic powder to treat the area...

https://rvpadmin.cce.cornell.edu/uploads/doc_480.pdf

[bikermike]

Thanks Nicos

I have been looking into dried garlic for horses.

One thing I'm not sure about is how to work out if I have managed to get rid of it. Does anybody know of any labs that can test for it?

[Nicos]

Just a thought....
Would testing samples give an accurate result?
I'm just thinking that you would probably select a few samples to send off and find different results for different localised areas and depths? A bit like pH testing?
Maybe trial and error would be the way to go..and a lot cheaper?

[bikermike]

The ever-tricky question about costs/value for a hobby...

I'll be losing that bed for alliums for a long time. I'll need to grow them at the opposite end of the plot next year, and hope it's not there. The actual ££ cost to me in terms of lost garlic revenue is small, but in terms of utility of the plot, that has a value I'm willing to spend against.

I get your point about risk of false negatives. I can minimise that to a large extent as I know where it came up. And it will depend on the cost.

If I do trial growths, there is an equal risk that I will feed the mould before I spot it's presence (the garlic powder trick seems very clever in that you trick it to deploy and exhaust it). And as it was partial across the bed, any test growth would either have to be across the whole bed or risk false negatives, plus disposal costs of contaminated stuff etc.

[Scarlet]

I had it about 10 years ago...I tried a few things but as you say the "true" feed it. I've grown everything else in that bed but you need to be careful not to carry any of that earth else where - when you harvest/compost etc.

I grow garlic elsewhere. I would only use garlic cloves from a good supplier now. I'm sure I brought it in with cheap cloves.

[Plot70]

The idea is that the dried garlic germinates the spores and then washes away leaving nothing for the fungus to live on.
It would be nice to find out what is in the garlic powder that triggers germination. If it is cheaper to make than garlic powder it would be useful.
You obviously loose the bed for a year with the powder but that is better than 10 years.

[bikermike]

ooh, people with experience of this problem!

Did you do the garlic? how much did you use? how often? Did it affect other crops in that bed?

Thanks

Mike

[Plot70]

The bed would be good for something that is not a bulb crop during garlic powder treatment.

[Mr Bones]

Our plot is covered in patches of white rot. The least affected row of elephant garlic was one I'd squeezed in unplanned where garlic had been grown the previous year. Maybe because affected bulbs (onion, garlic or elephant) are pulled up as soon as they show signs of infection, it's likely the white rot is triggered to grow but not allowed sufficient time to mature and seed.
For the last couple of years we've ignored crop rotation with onions & garlic and stuck to growing them in the same two beds which are drenched with diluted elephant garlic puree straight after the crop is lifted. Incidence has reduced from 50 to 25%, hopefully it'll keep dropping.
At least doing it this way the beds aren't lost and are planted up after harvest with a different quick crop that will be finished in time for the next autumn allium planting.

[bikermike]

Thanks - encouraging news.
Mr Bones - is it a one-hit with garlic or a repeated dose (weekly/monthly/every third Sunday after Septuagisma)?

Mike

[Mr Bones]

I'd guess the more times garlic drench is applied the better chance it has of working. We only apply once a year because that's all the spare ellie garlic we have. Typing this makes me realise it's high time I bought some garlic powder and gave the beds a double dosing.
It's mentioned in the link that Nicos posted that soil conditions need to be warm and damp, just a point to consider when applying.

Ps. Golden Bear onions (only available as seeds) are sold as downy mildew resistant but also display very good resistance to white rot.

[Nicos]

It says 135lb/acre...which is...0.0151314906 kg / m<sup>2

= 15 g /m2

Is that roughly what you use Bones?</sup>

[Mark_Riga]

The 'seeds' of white rot are small black grains that can remain in the soil for 20+ years waiting to be activated. I have an affected patch. It appears to be lessening now but I only grow autumn onion sets spaced at least 6" apart. This year, the crop which is still mainly in the ground, has had 3 affected onions so far. I remove the onion and use in the kitchen discarding the base and affected material. The top is composted. I then carefully dig out a square of soil with a border spade and discard that, in my case in the hedgerow opposite where it will do no harm but you could put it on a bonfire if you have one or somewhere aliums are never to be grown.

[Mr Bones]

It says 135lb/acre...which is...0.0151314906 kg / m<sup>2

= 15 g /m2

Is that roughly what you use Bones?</sup>

Don't know about the weight, I reckon I use about 2.5 fair sized ellie cloves per m2. Thanks for posting though Nicos I'm hoping to buy a pack of garlic powder, it'll give me a guide to work to.