Allotments 4 All

Hello all,

I have noticed some discolouration in the leaves of my maincrop onions. (Setton, from sets).

Firstly some background. All aliums on three adjacent 1.2m beds, manured late last summer after potatoes. Japanese onions and garlic planted late October, shallots and maincrop onion planted early spring.

All treated to a top dressing of bonemeal after planting and then of blood fish and bone when leaf growth starts. None of the aliums have been watered unless very dry, and since initial topdressings, have only had a couple of light feeds of Comfrey tea.

So far so good. All progressed superbly. Monster plants. Lifted our garlic last weekend due to a very light affliction of rust ( endemic on our allotments) starting to worsen. The bulbs were superb, except for one with Onion white rot!. It was only one, and other tenants commented on regularly losing a few to white rot each year.

Shaken but not stirred, I decided to lift The Japanese onions the following day, since the tops had mostly fallen, and it looked like we were in for some wetter weather. Fabulous onions, four times the yield of last year. All firm and healthy except five or six with white rot.

Now to the shallots. Still in the ground, and a week or so ago the leaves  progressively started to yellow a bit at the tips on the older leaves, . Probably normal, but it struck me that they were a while off ready, and they Had been universally lush not long before. Decided to give them a fed, to see if I got the expected burst of green new growth. New growth seems healthy,. Jury out on that one for now.
I also tugged at a few gently to see if they came away easily which would signify white rot, but they appear firm.

And so the the Maincrop onions around which my question revolves (Thankyou for bearing with me while I cut a short story long) Two days ago I noticed the leaves which are about three feet tall, and very lush growth, were starting to show quite noticeable pale alternating patches some of which have a discernable elongated ring around the pale area. I am not aware of this signifying white rot, and have given them a light feed to see if they perk up.

The reason for the rather extended overview of the alium patch is that they are perhaps a little to crammed in, in my pursuit of yield, and the rust and white rot may have contributed to making the area vulnerable to other diseases.

Has anybody ever experienced the symptoms I describe on the maincrop onion leaves, and if so, does it suggest disease or a nutritional deficiency?. I am hoping someone could shed some light in order for me to take the right remedial action ( even if that is nothing, which is so often the case)

A botrytis fungus of some kind? pictures on the web generally show far more advanced cases, so I am unsure.

Help!. I must have my onions, shop bought just wont hack it anymore.

Hopefully someone has seen this before, and can advise. I will try to post photos tommorow.

plot88(Cardiff)

I'll leave it for the photo's then...  :-\

Oval rings sounds like leaf blight.

http://vegetablemdonline.ppath.cornell.edu/factsheets/Onion_Botrytis.htm

Thanks for the responses.

Sorry about the lack of photos, but I didn't bring the camera this evening. Thought I'd post just in case someone knew instantly what this was.  I suppose I will have to shamelessly bump this post tomorrow when I get a couple of pics.

Leaf Blight? I wondered about that. Most accounts describe the development of lesions, but this is not advanced yet so difficult to tell.
Anyone know of practical approaches to combating leaf blight available to the mostly organic allotment gardener?

Cheers
Plot88(Cardiff)