Nick wrote after..
Wally wrote:
A couple of my potatoes where looking a bit sick and
laying flat, so not knowing what the prob was I dug
one of them up to see what lay beneath.
All the potatoes seemed OK but quite small and not
fully developed.
The only thing that I could see that may be the trouble
was red ants although they don't seem to have attacked
the tubers.
Do ants affect root crops, should I be concerned about them
and lastly how do I get rid of them???

No.

Look on the roots of the potatoes; if you see small (c. 1mm) spheres
of translucent whatever, you have eelworm.

Also, if you have had the dry weather we have had in the last month or so it
could simply be lack of water.

--
Regards
Bob Hobden
just W. of London