Bright yellow patches on potato leaves

[Nes]

I noticed today that one of my first early potato plants (I think it's a pentland javelin, though I also have Bonnie Dundee and Ulster Classic in the same bed, and can't be sure which it is without hunting for a label ) has bright yellow patches on some of its leaves, while the rest of the leaf is a healthy dark green. Otherwise the plant seems perfectly healthy, as do the rest of the plants in the bed. Should I be worried? Or can I leave it be for a little while longer?

[shirlthegirl43]

How long have they been in? It is usual for the foliage to yellow and die off when the crop is ready.

[Nes]

It doesn't look like they're dying off. The patches are just that - distinct patches, with a real edge to them, where yellow meets green. The plants have been in for a while, and it'll soon be time to dig them up anyway, though I think Pentland is a bit later than other first earlies...

[shirlthegirl43]

To be honest, it sounds to me like it is just getting on for harvest time.

According to Dr Hessayon, yellow on leaves could be mosaic virus or frost, maybe you can google those and see if they are similar.

[Geo]

Potato aucuba mosaic virus?

Causes yellow spotting or necrosis of potato leaves and necrosis in potato tubers, but is rare and consequently of little economic importance.


>>>Click<<<


Geo..

[Geo]

Great minds think a like

Geo..

[shirlthegirl43]

LOL, thanks for the compliment Geo

Oh, wait a minute, you meant Dr Hessayon

[tattieman]

Could it be where water has got onto the leaves and been scorched by the sun?

[Nes]

Thanks for your replies and ideas.
I'm now wondering if it's alfalfa mosaic virus, though I'm not sure where it could have come from
Best dig it up and get rid of the risk of spreading something nasty to the rest of my tatties... unless anyone has any other advice?

[Nes]

Tattieman, I don't think it's scorch, as it's only on one plant in a 4m double row. I also haven't watered them recently, and it's not rained for more than a week.

[shirlthegirl43]

http://www.ipm.ucdavis.edu/PMG/GARDE...famosvirus.jpg here's a picture, does it help any?

[tattieman]

Unless the plant starts to die I would just leave it. It might have had aphids or other pests that have bitten the leaves and damaged them. If it starts to look unhealthy then remove it and dig the spuds out aswell.

[Nes]

Shirlthegirl, the yellow is about right, but the patches are more discreet than that, so am still confused

Tattieman, thanks for the reassuring advice. Will do

[tattieman]

Does it look like some one has splashed yellow paint on your plant with a brush?
If so I have one like it and I am not worried.

[Nes]

Does it look like some one has splashed yellow paint on your plant with a brush?
If so I have one like it and I am not worried.

Yes! Oh good. Will leave it alone for a while longer then, but will keep an eye on it. Cheers!