[jambop]

We have had some high temperatures over the last couple of weeks and my spuds were already approaching the point where the would be ready to start haresting. Am I correct in thinking that potatoes stop growing after they have been exposed to a high temperature for a period of time?

[Yorkie]

I hadn't previously heard that - if you still have leaves that are providing nourishment to the tubers, I'd have thought there is still a chance of the tubers growing more.

[sunshineband]

I've not heard that either, except in the contaxt of them needing more water to keep growing when it is really hot. There is a lot of leaf cover there to transpire water out of the plant in high temperatures.
I flood mine along the gullies between earthed up rows, so the water soaks in well and does not evaporate. Keeps the leaves dry too