Manure & Slugs

Last autumn I manured most of the patch where my spuds were to go but I don't quite have enough and left an area the size of 2 rows of spuds un-manured.

About a week ago I began to lift my maincrop spuds and I started with the 2 rows that had not been manure. Virtually every single spud from that area had been very badly slugged and are unusable.

Today I started to lift the spuds from the manured area & they have been untouched by slugs and are lovely spuds. I don't know whether this is just luck or has anyone else had a similar experience.

I did add a bit in the trench this year and I must say not too many have been slugged..  I'm going to do it deep this year..

Were they all the same variety?

No to be fair they weren't, the slugged variety were Maris Piper & Marfona.
The non slugged variety were Desiree.

This year I put a a good helping of manure in the trenches, and put the seed potatoes directly on top of the manure.  Had to throw half away due to slug damage.  3rd year now of throwing half of them away due to slug damage, previous years did not use manure.  Now I won't be doing tatties in the allotment soil in future, instead doing them in containers and grow bags.  Maybe my plot is just a slug paradise, as I had slug damage on my carrots, and beetroot too last year.  And this year they already eaten my kale, cabbages, cauliflower, purple sprouting, sprouts.  I know it has to be them cos it's all under netting.