[Mark's Sussex Allotment]

Hi Guys,

I have this weird rusty looking pattern on my potato leaves and some of them are wilting.

They are in the poly tunnel and are almost ready to flower

Any idea what it is and is it serious?

[mumofstig]

Photo might help 

[Welsh Merf]

Err . . . there is a photo mummy! 

[Yorkie]

I don't think it's blight; it looks more like a nutrient deficiency. What, if anything, have you been feeding them with?

[Mark's Sussex Allotment]

They have had pototo fertiliser added to the mix, but havent fed them since they were planted in february.

Could it be underwatering?

Too much feed in the mix?

[mumofstig]

Err . . . there is a photo mummy! 

There is now 

[Steveharford]

Looks more to me like something untoward in the compost. I merrily spread loads of grass cuttings around mine once. Only later did it dawn on me that the grass had been professionally treated not long before. My spuds looked like that

[Mark's Sussex Allotment]

The compost is Verve from B&Q and the only thing added was some organic potato fertiliser.

[Steveharford]

Ive got mine in verve too. Seem ok at the moment

[mumofstig]

Maybe magnesium deficiency  could try spraying with epsom salts mix on a morning so they dry out before you close up in the evening.

[Mark's Sussex Allotment]

I thought that too. Thought they would be more yellow though.....

It's a shame, i was really hoping someone on here would tell me straight away

Thanks for the help guys

[Eightball]

I would say it's damage from thrips. They can spread something called tomato spotted wilt virus which kinda looks like this. I had it a little bit on some of my tomatoes last year and I assume as potatoes are in the same family they can get it to.
http://www.bbc.co.uk/gardening/advice/pests_and_diseases/identifier.shtml?thrips

[Paul Plots]

I would say it's damage from thrips. They can spread something called tomato spotted wilt virus which kinda looks like this. I had it a little bit on some of my tomatoes last year and I assume as potatoes are in the same family they can get it to.
http://www.bbc.co.uk/gardening/advice/pests_and_diseases/identifier.shtml?thrips

I think you may be on the right path Eightball..... The leaves look as if they are developing something rather than lacking something. Darkish, dry dusty spots.

How much ventilation is there through the tunnel? I'm wondering if something is having a quiet nibble and might have introduced a form of mildew... that and the cold / slow growing conditions seems to have knocked them back perhaps?

[BabbyAnn]

I think virus is a more likely cause - try googling mosaic virus and look at images

[Headgardener22]

What variety of potato are they? Is it all your spuds or just some?