Topic: New onion problem

[Froglegs]

Our allotments have all been hit by a new(new to us)onion problem the symptoms are stunted growth,twisted leaves and early bolting.  Anybody out there got the same ?

[BAK]

Yes - got it here (Sunningdale Berks).

Just sent a sample off to RHS to get their view.

[Tee Gee]

Have they been grown from setts or seed?

I am finding that setts over the last few years have been rather pathetic, last year I didn't harvest any grown from setts, seed grown ones were OK.
 
Plus having read about the  problems some of you are having with with DTB seeds I am wondering if suppliers of the seed who supply the seeds merchants are taking shortcuts in order to make a profit.

That is; are the seed merchants screwing the suppliers down so far that they( the suppliers) are having to take shortcuts to make a living, and as always it's the end user that suffers most.

I will be interested in the RHS' s findings

[antipodes]

This is what I have had and am having again this year. It is caused by a larva. Open up one of the affected onions and you will see a brown bug inside, quite small. It seems to eat into the skin and affects the growth of the layers of the onions. I am afraid that I lost a lot of onions through this last year.

[antipodes]

Found last year's thread with pics:
http://www.allotments4all.co.uk/smf/index.php/topic,75838.msg772838.html#msg772838

[BAK]

Mine are sets ... Centurion and Picko Bello.

Other people on our site are suffering from similar problems ... though by no means all.

[bluecar]

It could be due to the allium leaf miner which also results in twisted and stunted plants.

Regards

Bluecar

[antipodes]

bluecar I think you have it spot on.
Read this document to see good tips. Seems like the onions now have to be fleeced too, along with all the rest!
http://www.docstoc.com/docs/150702553/Allium-leaf-miner---Magazine

[bluecar]

Hello Antipodes.

Thanks for the link.

I've been covering my onion, leek and garlic plants for 3 years now (debris netting) and it seems to work. I just wish some of my fellow plotholders would do the same or if when they get attacked (which they do) destroy the plants rather than leaving them in and allowing the problem to perpetuate and obviously spread. On our site, whilst I cover as mentioned, my casual observation is that onions are more susceptible, then leeks and garlic seems to be okay..

Regards

Bluecar

[antipodes]

I have it again in my onions, even though I rotated, and I have removed all the ones that look affected. Sometimes you can't tell though until they are at maturity.
I did have some success with seed onions this year and those I had fleeced as they were planted among the carrots. They stayed fleeced till just recently and so they seem untouched.
Hard to know what to do. Maybe next year I will just do some echalotes and red onions and fleece them. I did a lot of onions at first as they are an easy way to fill the plot, but now the plot is half the size, I think I will do less of them, even though they have usually been a good crop for me.

[BAK]

As mentioned above, I sent a sample to the RHS.

Here is a brief summary of their reply.

There were no signs of any root problems, pest, stem / leaf nematode or mildew.

Lots of people around the country have been reporting similar problems.

They think that it is weather-related. Soft lush growth in April on sets or plants put out in February or March. This made them vulnerable to damage with the adverse weather conditions in early May.   

[antipodes]

I think that if the pupa have been in too long you no longer see the actual pest. All I can say is that 1) the leaves tend to curl, 2) the growth is checked 3) there is often rotting around the bulb and sometimes you can see damaged areas. You really have to take them out and cut into them to see if you can find the wee beasties which are a reddish brown and about 4 to 6 mm long.

Sorry to say that it doesn't sound anything like weather damage to me!!! Surely they would all have been affected then??

[springs]

Every one on are plots have suffered the same, sorry but no sign of little beasties, we all put it down to the weather . Never had anything like it on the plot before hope .we don't have it again

[juju]

We too in Leicester have suffered the same fate with onion sets but the onions that were set in October last were not effected. I think I will stick to winter onion planting. I do hope this onion madness is confined to 2014 and not passed on to next year. pickling onions will be quite expensive  this year.

[BAK]

Just harvested our onions. To continue the story from above ..

The vast majority of the onions recovered from the stunted / distorted growth in late May. There has been no subsequent sign of any pest / disease. The crop is OKish.

[chriscross1966]

My first thought was thrips or allium fly, but your crop would not have recovered from them...

[Robert_Brenchley]

When I had onion fly they never recovered.