Have I got blight?

[nick nack]

Hello grapes

Can any of you let me know if the plants in the pictures have blight?

Thanks

NN

[Nicos]

Yep- looks like first signs to me
How many plants do you have?
I'd be tempted to chop off ALL the top growth now to rescue the spuds. They'll be fine if left in the soil for now if undisturbed. ( just dig what you need , when you need it.)
Mine looked like that 3 weeks ago and the whole lot was affected 2 wks later.
If you are lucky enough to be in a rain- free area , then you could try spraying with copper sulphate a couple of times a week.
(Ha ha...just noticed you are in Cheshire too!- wonderful hail stones and thunderstorm we're having as I type eh???)
I've found that all my spuds are at least twice their normal size, so we didn't lose out on taking the haulms off early.

Blighted spuds don't keep so you'll need to tuck into them!!

[nick nack]

Thanks Nicos. Guess what I am doing tonight?

NN

[HeyWayne]

Bugger, looks like I have it too!

A few of my potato plants look like that.

[nick nack]

Sorry Wayne for spoiling your day.

NN

[HeyWayne]

Sorry Wayne for spoiling your day.

NN

No worries, I wasn't sure if it was part of the "dying back" process, I hoped it was, but hey-ho!

[nick nack]

Wayne

I thought it was part of the dying back but thought I just make sure. Good job I did I might have been left with nothing, at leats got a chance to save the crop.

NN

[jondanie]

Nick,
The pics does seem to show a small blight infection. However the infection isn't too serious right now (but that can change very quickly) and you still have a lot of green leaf. Personally, I would pull off the infected leaves, remove from your plot and spray ASAP, with Dithane or even a copper sulphate (Bordeaux or Burgandy mix) I wouldn't take off the entire foliage at this stage (unless they are say second earlies where the spuds should be almost full size by now)

Once potatoes reach a certain growth stage, the foliage isn't really needed for the spuds to bulk up, to give a reasonable crop. Maincrops need to stay growing much longer to get any worthwhile yield.

hope this helps,

[nick nack]

jondanie

Thanks for the info, it puts a different light on the matter. Can the products you mention be applied on wet foliage (peeing down in Stockport at the moment) or does it have to be very dry?

NN

[veggiemo]

Hi nik nak,

I think I'd agree with Nicos. Once the spores have reached the stems as yours seem to have done it is usually too late. The commercial sprays are expensive and you will probably be paying out good money for nothing. The sprays really only seem to work if they are used before any signs of blight, i.e. if the national Blight Watch website, or someone else local to you warns that blight is about but you don't yet have any signs.

That was the reason for my original post, most of us will also inform our neighbours so that they can take action. If one garden/allotment has infection it will spread like wildfire in the wind an the rain.

Like Nicos, I also have a reasonable harvest even this early, and I planted mine very late this year. If you leave it too long you stand a good chance of lossing what could be a healty crop.

Good luck nik nak

[jondanie]

You're welcome Nick,

The aim of spraying now is to kill as much of the blight infection already there (not always possible though)

The trick is to apply the spray at one and a half times strength (check the label) in bright sunshine (mid-day sun, you might need to wait a while!) Make sure you cover under the leaves and stems as well. So you'll need a dry day(preferably sunny day) for this spray.

The combination of spray and sunlight will dessicate almost all of the blight spores already there.

I would use Dithane now, the copper based sprays are best for later on, to protect against tuber blight. The Burgundy Mix is easier to mix and apply. I'll give you the "recipe" if you want it.

Hope this helps.

[nick nack]

Jondanie

Once again thnaks for the info. What is this 'burgundy mix'. Yes I will have the recipe if I dont use it now I will be prepared for later on and probably other grapes could do with it.

If I remove the foliage will I still have to spray with the mix?

NN

[nick nack]

Well Grapes

I have removed all the top growth from the potatoes and I will leave them in the ground as suggested. Will let you know if the crop was greatly affected.

Thanks again for all the help.

NN

[MURFE 18]

Hi,Nick Nack,
it say,s in the books that you can only leave in ground for a short while [ 2 weeks] before they start to rot and slugs take over, i have the blight this year and so do a few others on site. have striped tops and burned them now removing spuds it also say,s they do not keep very well either, good luck

[jondanie]

Nick,
Burgundy Mix is an old blight spray used long before modern sprays were developed. It's a mix of copper sulphate (bluestone) and sodium bicarbonate (baking soda) It's made as a 1% solution, don't make it stronger as it injuries the leaves and it doesn't improve the blight control.

Mix for 10 litres (adjust quantities upwards depending on how much you need)

100g Copper Sulphate
125g Baking soda

Mix and dissolve each ingredient separately, then add the baking soda solution to the copper sulphate solution. NOT THE OTHER WAY ROUND! Then make up to 10 litres. Best used on same day as it's made.

Since you've chopped off all the foliage already, you don't need to spray. I would have left the foliage and sprayed as I suggested previously.

I would be highly surprised if any blight spores have reached your spuds, they should be fine. Best to do as previous posters have said and use them

Hope this helps,