Topic: Calling Onion Experts..what's this ??

[vegmandan]

I'm having a problem with some of my Exhibition Onion seedlings.

The top 1 cm ,no more, of some is just shrivelling up.

I am at a loss as to what it is that's happening.

I'm growing them indoors under lights in a well ventilated space so I dont think it's a fungal problem,and it is only affecting some,and only the top inch of the leaf ??

It's not travelling down the leaf but just affecting the top inch ?

Anyone got any ideas ?

Cheers. :(

[Lauren S]

I think Tee Gee will be able to help you out with the answers.
Sorry I'm no help ::)

[flossy]

   I don't know , but will take a risk and say I would cut the infected ? parts off .

   floss x

[cambourne7]

cut one off open the inside and see if there is anything inside??

[Tee Gee]

I think Tee Gee will be able to help you out with the answers.

Thanks for the confidence you have in me Lauren but in this case I am not totally sure. ???

Looking closer at the picture (see ringed section) I think something has been nibbling at it see here;



If this is the case the plant might have been weakened by it and died off, or indeed the plant may have been virused by the event I am not really sure  ???

I could do with a bit more information though for the following reasons;

Because of 'close up' photography I am not sure how big this plant is, and it might just be that it has naturally withered away i.e.

When a seedling reaches the 'crook' stage i.e. the top of the stem bends over this kink can cause the leaf tip to wither away.

I tend to use the crook stage as a sign to prick out and this withering seems to be a plant mechanism to encourage secondary leaves so my first question is;

Has this plant been pricked out yet?

Next question could it have been 'frosted' perhaps touching the glass of the greenhouse?

How high is that nibbled area above soil level? Why I ask is;..... could it be that some rodent (mouse/rat) has got at it?

How are all your other seedlings?

Sorry for being so vague but a picture, choose how good it is, (as this one is)  can beat 'hands on' when trying to resolve a question......Tg

[vegmandan]

Hi to give a bit more info,the plants are only about 4-6 inches tall,each in a 4 inch pot,grown from pips inside my house under CFL lights.

The photo appears to suggest they are bigger than they actually are,the withered bit is actually less than 1cm in length.

About half of my seedlings have got the same thing, from the biggest to the smallest,with no pattern to the infection(or whatever it is)just  random  attacks.

I'm going to give them a blast with Dithane just to be on the safe side  ???

[growmore]

Are or have you occasionally mist sprayed them ? .
Is there now or was there any condensation dropping on them?.

[davyw1]

DAN you say you have grown them from pips so its possible that it may have not been stripped back that extra leaf. If i was you i would trim of the tip because you are going to loose that leaf any way so it wont make any difference.

[vegmandan]

DAN you say you have grown them from pips so its possible that it may have not been stripped back that extra leaf. If i was you i would trim of the tip because you are going to loose that leaf any way so it wont make any difference.

Cheers,I just planted them as they came  ??? I didn't strip them or anything as I didn't know what to do not having grown pips before.

I think I might have overwatered to be honest and when they transpired moisture to the tip at night ,the lights might have scorched them the next morning,so I'll raise the lights a bit and be more careful watering wise. :)

[Tee Gee]

I think I might have overwatered to be honest

This is quite a common problem after forty years+ I don't always get it right.

I find that temperature and plant size plays a big part in the success of this.

Try this for an idea; You may have noticed from time to time some of the A4A members refer to young plants as their 'babies' well I think there is a bit of truth in this.

For example a baby is weened onto its liquid intake i.e. it is increased as the baby grows I think it is the same with plants, increase the water in relation to the root system ie small root system low quantities of moisture increasing as the root system increases.

The other thing is I drink more in warm weather than I do if it is cool, again this is the case with plants.

the lights might have scorched them the next morning,so I'll raise the lights a bit and be more careful watering wise.

Now that I know how you are growing them I would say your thoughts are justified.
When I first replied I did think of some form of 'scorching' although my first thoughts were frost.

Consider this as a tool for watering; Use a hand held spray rather than a watering can and give the plants a blast daily until such times as they start taking up more moisture.

I find adding a fertiliser at half strength and a fungicide at recommended strength to the spray gives a foliar feed and wards of any fungal disease that might develop because of fluctuating temperatures.

But that's up to you!!

[Sparkly]

Sorry maybe I am dim, but what is a 'pip'?

[vegmandan]

Sorry maybe I am dim, but what is a 'pip'?

A pip is an alternative to a seed,sometimes you get a few pips forming at the expense of lots of seeds in a seed head.
They look like small onion sets.

Here's me sounding like I know what I'm talking about... ;D

Anyway this is a pic of one of my pips just after it sprouted.

P.S your not dim,this is the first year I've ever grown any,let alone seen one.

Might be the last at this rate  ;)

[growmore]

I would suggest you only water from bottom avoid spraying or misting amd keep watering to a mnimum ..With having them in heat and lights they are gonna   be real tender plants..
You dont want to create too much humidity or subject em to shocks with spraying ..
davyw1 is the guy who knows his onions.  I would  ask his advice and do as he says..

[davyw1]

Dan that soil is far to moist, you will rot the pip. The best way to gauge if they need watering is by weight. Bottom water by dipping them (letting them stand for a while in slightly warm water and let the soil absorb the water.) Try and keep the top soil dry but moist where the roots are to force them down. Constantly check the the bottom of the pots for roots, when you can see the root then they are ready to be potted on into larger pots in M3 compost. REMEMBER there is only six weeks feed in multi purpose and M£ compost

ONION PIPS. When a seed head develops you get the seed pods from which you collect the seed. If you look into the seed head you can see what looks like a mini onion set, its from these that you grow the super big onions. You can only get them from the large onion.

[realfood]

Checked the three onion seed heads today that I had allowed to mature, but no sign of pips. Is it a particular variety of onion that produces pips?

[davyw1]

Checked the three onion seed heads today that I had allowed to mature, but no sign of pips. Is it a particular variety of onion that produces pips?

We are talking exhibition onions in excess of 12lb that have been put back to seed not let go to seed.

[Eristic]

onions in excess of 12lb that have been put back to seed not let go to seed.

But is there a difference?

[littlebabybird]

that have been put back to seed not let go to seed.

sorry can you explain this please?
lbb

[davyw1]

onions in excess of 12lb that have been put back to seed not let go to seed.

But is there a difference?

I don,t suppose there is, but you are not guaranteed it will go to seed before it gets neck rot, dies back, falls over or rots off also it has to be moved to over winter it which means disturbing the roots which is no good for the onion.

Quote from: davyw1 on Yesterday at 19:53:07
that have been put back to seed not let go to seed.

sorry can you explain this please?
lbb

If you go to a vegetable show you will find that in the rules of showing that the exhibitors can only lift ( take off the bench before auction ) are leeks and onion from seed. This so you can,t get their breed of onion or leek. If an exhibitor has not lifted them then he will of spiked them ( pushed a knitting needle from the roots up the centre of the leek or onion so it does not go to seed.

To put an onion back to seed you need to dry it out first, you cut back the stalk to not less than one inch not more than two.take of all the dead outside skin and trim of all the old roots and place it upside down  in a tube or bucket to drain ( most of the badness is in the neck ) and dry out, this can take up to six weeks.
When you are sure the onion is drained and dried out you then re plant it in a bucket and it starts to grow again producing the seed head. If you have done it correctly the seed head should be ready the back end of October for you take the seed and pips to be planted the second week in November at the latest.

[realfood]

Thanks Davyw1 for that explanation. After a lot of Googleing, I came across Medwyn Williams website, where he has a series of articles covering various aspects of vegetable growing including getting onions and leeks to form pips. His method appears to be allowing the plant to flower, but then cut off the individual flowers, not the head. In a last ditch attempt to reproduce, the plant forms pips.
There are also hints on growing your pips to exhibition size, though you need to trawl through many of his articles to find them, which may be of interest to Vegmandan.