Just noticed these spots appearing on some of the leaves of my Maori potatoes being grown in a jute coffee sack. Plant otherwise looks healthy, and i don't see any insects. It's not new or old growth affected.polka dots on tomato leaves

1 Answer 1


Looks almost as if the leaves have had something dropped on them, but the likeliest explanation is, unfortunately, some type of potato virus - if the lower leaves start to go completely yellow, or other symptoms appear, you'll know its a virus. However, sometimes there isn't that much to see on the leaves, but the tubers will be affected in some way. There are a lot of viruses which affect potatoes and many haven't even got proper names, being listed as things like 'potato virus Y' or whatever, but there is some information in the link below regarding viral infection


  • Looks most like Alfalfa mosaic virus from the mosaic patterning on the leaves. I guess I should pull the plants out and dispose of them, as well as the soil. Commented Jan 30, 2016 at 19:06
  • Sadly, yes but when you do, check the tubers, see what symptoms you can see there, might help to identify precisely which virus it is...
    – Bamboo
    Commented Jan 31, 2016 at 12:29
  • Just some tiny tubers present. Nothing obviously wrong with them otherwise but a very poor result after 3.5 months in the sack. Another reason to avoid using sprouting potatoes given to you by friends, and not certified seed potatoes. Commented Feb 2, 2016 at 0:51

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