Potato Scab

Dry weather and alkaline conditions can lead to common scab.

You have to keep the tubers watered whilst developing and avoid lime.

The vast majority of my spuds seem to have common scab on them.  Can anyone give me tips on how to stop this from happening next year?

Also, is it me or is anyone else havind difficulty keeping on top of the amount of weeds there are this year?!! 

The fungus responsibile thrives in sandy soils with relatively high pH, which I wouldn't think was a common combination unless it's been recently limed.

Plenty of organic matter, no liming, and attention to watering all help (my soil is sandy but I've only seen the occasional trace of it on my spuds.)

As for weeds, there will always be a problem with annual weeds if you let them seed, and perennial weeds if you don't dig them right out. It is also quite easy to recycle weeds via the compost heap if you compost weedy material and the heap doesn't heat up enough to kill any seeds on them.