Topic: White Rot

[dicky]

Our onions and garlic were starting to die off a little earlier than expected, so a gentle tug on a few of them found them far too easy to pull up and with the dreaded white rot. Add to that Nematodes and some strange red bug in between the layer. 3 out of 30 storable....doh..

So has anyone got any ideas what the little red bugs between the layers of the bulb could be?

Also am I safe to just dig the ground over and use it for squashes straight away?

[Plot22]

Dicky

I am hoping it's not because my site is inundated for the last 2 years with allium leaf miner. Try this link which I hope that I have copied it correctly from an American site  www.ento.psu.edu/extension/ve/pest-alert-allium-leafminer. It shows the little red bugs that have turned from maggots and will eventually turn to flies in September. I think you may have to put it in manually as the link does not seem to work but it does show the bugs.

[johhnyco15]

our whole site has been affected this year really bad my white onions lost the two rows completely  brown onions 1 in 3 usable  red the same even shallots decimated a real bad year I've a load of later planted onions so far unaffected but im sure that will change in the next few weeks  the thing is nothing has been grown on this patch of ground for at least 8 years this is why i put them there  defo no onions for me next year its aldi for me in future 49p a kilo it really aint worth the stress

[squeezyjohn]

I've had it here too ... some of the garlics keeling over.  I suspect it could be a very bad year due to the conditions in spring.

[Pescador]

There's been quite a lot said about White Rot on this forum in the last couple of years, which you can find using "Search".
Here's one link https://www.allotments4all.co.uk/smf/index.php/topic,78831.msg798157.html#msg798157
I've got some garlic growing well at the moment in a patch that I treated with garlic powder last year, having had terrible problems previously.
All seems well at the moment!

[Paulh]

I've had both white onion rot and rust on my garlic in previous years but this year has been successful. First, I've not watered the garlic except when it looks very dry - I think the moisture helps the rust in particular. For the first time in ten years of growing garlic, I've had no rust (the garlic is OK too). Second, watch the plants like a hawk (though don't try to hover over them). If one looks weak, dig it up. If it has white rot, get the whole lot up. Don't put it off. I did that this weekend and found say 8 out of 50 odd affected. By next weekend it would be at least 24, based on what I didn't do last year. I'll have to watch what I've harvested, but I'm feeling optimistic.

I'm trying the garlic powder, working on the basis of digging it into the plot wherever I'm working on it unless I'm going to plant onions etc., there this season (no point in giving it a head start). My problem is finding a reliable internet supplier who will send a few KGs of the stuff without reneging on their delivery rates ...

Any other experiences would be interesting.

[squeezyjohn]

Well I did the full garlic powder treatment on the bed I found a garlic with white rot in it ... so it's not massively encouraging.

[lezelle]

Hi Ya, Laurieuk did a thread on white rot and advocated the use of garlic powder to kill off the spores. Very good thread so look it up it's interesting. I am trying the treatment and so far so good. Good luck

[squeezyjohn]

Yes I know it's a great thread and a very interesting theory ... I prepared all my allium beds with several garlic powder treatments last autumn and again this spring, and despite that I still have fairly extensive white rot on my garlics.  It makes me wonder whether any good results that people have seen have been purely coincidence with years where the weather makes white-rot less common.

[johhnyco15]

this subject was on gardeners question time a few weeks ago  the question was we like to grow big onions but we get white rot can the panel help the reply was dont grow onions there is no available cure for white rot you can use all the garlic powder amilotox and the like it wont work some years are worse than others depending on the weather so you pay your money you take your choice

[Tee Gee]

Question: ?

Having read the above comments I would like to know from the people that have contracted this problem did you use "Seed Sown" Onions or "Onion Sets"?

I have had my plots for around thirty years now and luckily  have only been affected once, which must be around fifteen years ago now.

 Maybe it the cynic or the skepticism in me but I think it is possibly the quality of the stock we are receiving  from the seed merchants and / or possibly the quality of our gardening techniques, in particular gardening hygiene, or a bit of both.

Over the last few years I have purchased sets from various places e.g. Marshall's, D.T Browns, Pound Shops, and from stall holders  at the NVS Vegetable show in Harrogate and the quality of my onions (in some cases I was ashamed to call them that) were rubbish, and would you believe it the Pound Shop stock was as good as any.

Now I do not know how these people source their stock but I guess it is the residue after the 'selected' stock has been sold to the big names in the industry.

The tell tale sign is that they are usually very small.

Could the fact be that they are small is the answer? that is: Small is best!...could it be that they do not contain any virus wheras larger one might do????

For instance if a Dahlia or a Chrysant stool becomes virused one usually roots tiny tip cuttings as opposed to the traditional 2"-3" long ones as it is said the tip of new growth is virus free.

Then of course there is micro-culture but that's another story!

I have this hunch  based on my experience with viruses when I exhibited my wares, that is: we only bought stock from trusted sources and if you think about it..... to get the best onion seed..... you get them from the top growers who have saved their own seed.

People like Medwyn and Robinsons are usually quite good but even here they select the best seed for themselves and sell the residue commercially.

This year I have gone back to "Seed Sown" onions having purchased the seed from D T Brown. The varieties I have sown are "Exhibition" and "Red Baron"

I looked at them this morning and the tops and necks seem quite healthy for the time of the year they are in the bed that suffered from White Rot all those years ago so fingers crossed hears hoping Iam onto a winner this year....only time will tell.

By the way I never use the "dig in onion tops" or "garlic powder"  options my theory is get rid of what might be the "Winter Host" plants so I prepare my beds thoroughly in Oct/Nov and remove all weeds.

In spring before planting out I  remove any weeds that have germinated, my hope is that by doing doing these two tasks I have greatly cut down on the chances of getting white rot. This was what I was meaning about garden hygiene.

So that folks is my slant on the problem.......what do you think?

[johhnyco15]

in reply tg i do agree in some cases bad stock is the culprit however ive grown onions ,shallots all from seed on different parts of my plot with the same outcome a fellow two plots from swears that he never gets white rot as he saves his own seed each year this year he has not one onion out of the 80 he planted

[squeezyjohn]

My garlic was grown from sets as it has to be because garlic doesn't make seeds.

My onions, however are all seed sown ones ... so it will be interesting to see if I get any problems there.  I have always had more problems with white rot on garlic than on my onions.

I agree that the sets are awful, they always go to flower for me and won't store, but with seed sown ones - I've not yet had a single one bolt on me.

[Digeroo]

I am growing from set from Local garden centre Wyevale.  Doing ok at the moment.  One has gone to seed and one failed to grow though I did not plant a few soft ones.
Preferred the previous garden centre regime, they used to have them loose, which was much cheaper and you could mix the varieties with a few of each.   And you could ensure they were all good and hard.  But actually more of their went to flower especially the red ones. 
I do not like onions, so grow them more as a protection for carrots.

[pumkinlover]

Some interesting thoughts.

[lezelle]

Hi Ya, Some very interesting info there TG and has got me thinking. I had noticed the setts I purchased from Robinsons seemed to be very small to what I used to buy. I have considered using seed and indeed one of my over wintering onions is throwing a seed head and I have left it to gather seed. I also thought about picking the little plantlets like you do with leeks, would that work i wonder? I did try the garlic treatment this year but it has been so dry that the onions are not fairing well and I have one overwinter one showing signs of white rot. With onions being, in my opinion shallow rooted, the white rot spores must be shallow and being dry, well who can say. It will be very interesting to see how the out come is for different people and areas. Much to think about. What works for some does not suit others. Seed or setts, what a nice dilemma to have for next year. Happy gardening

[Paulh]

TG, your "garden hygiene" is going to be good for diseases like rust which I recall can be held by weeds but I'm not sure it would have any effect on white rot where the dormant spores lie in the soil. The hygiene there would be to keep separate parts of the plot quarantined which is beyond most of us, though I guess easier with raised beds and a no dig policy.

As I understand it, the garlic treatment works by triggering the spores into life which then find there is nothing for them to grow on. My concern is that I would not want to wake them all up and have them still ready to go when I plant my garlic. I've not seen any suggestion how long the awoken spores can remain viable. So my strategy is to treat all my plot when I am digging it unless I am going to grow the onion family there within the next 12 months. You also have to treat several inches depth of soil, so I am not sure how effective one treatment will be.

TG may well be correct that some years are generally better or worse for white rot and this year I have been fortunate. We'll see how my onions fare.

[laurieuk]

As I have said previously I have used garlic powder and it CLEARED the white rot but there are conditions that some may not like to use.  It has to be used while the spores are alive which means as soon as the crop is cleared also I use the same plot each year for my onions. I  used the same area for many years in the gardens where I worked before retirement as it was a good place. White rot is carried over in the soil so walking on it can spread it back onto clean soil. It is the only thing I have found that worked despite many years of trying.

[BarriedaleNick]

For the garlic treatment to be effective at all I think you need several things in play.  The soil needs to be warm and you need to get the garlic/onion "soup" into the soil so ideally when it is raining and the soil is already wet.  Then do it again a week or two later maybe turning the soil over a little.  Even then it is difficult to tell if it has been effective - as TG mentions some years are good/some bad.  I would say it does have some effect. My plot was terrible for it and always lost so many onions - over the last few years I have been doing
 the garlic method I have lost none or a few.  So confident now that I forgot to actually treat a bed last year!!