[tonydevine125]

Why did my potato plants die yet have many under-developed potatoes which looked OK except for their size?

[flitwickone]

photos of the plants would be good someone will probably identify the cause

[DD.]

As well as the variety.

[JayG]

Have a very close look at the roots of the plants you have dug up; if there are some or possibly many round, pinhead-sized, whitish or yellowish structures attached to the roots your spuds have suffered from eelworm attack, which causes premature die-back and consequently small tubers. The tubers may (but don't always) also have cysts attached (you can eat the tubers but you won't get fat!)

If not then back to the drawing board and yes, more info and preferably a pic!

[peapod]

Far too many possibilities, and JayG listed one of those! Pics really are required and could help other people too  

[mumofstig]

we don't know where you are, so it may even have been drought conditions

[Muddylou]

Why did my potato plants die yet have many under-developed potatoes which looked OK except for their size?

My first earlies (Lady Chrystl) are pretty much like that, some plants with only two medium potatoes, some with a few small pots and every now and again I get a plant with a large yield of large pots. I'm sure it's the very dry weather we had. They taste very nice though.

[Jay The Digger]

My Desiree and maris pipers have both suffered with this problem.  My Charlottes were fine, but they were out early. 

Everyone on my plot seems to have been affected, which makes me think the weather is the culprit.   The tubers are the size of large marbles with a handful about golf ball size despite regular watering.  The plants have started to die back, so they aint gonna get much bigger. 

These mediterranean summers don't suit everything.  My sweetcorn on the other hand has gone crazy !!!!!