[ferreter51]

I've been growing potatoes for several years, but only for two in my present kitchen garden but I've never seen damage like this before.  About 50% of my Desiree tubers have slug damage, but 10% also have large, apparantly chewed-out areas.

I attach a photo of one tuber showing 'normal' slug damage marked with an 'A', but the larger area is what I haven't seen before.  Could it be rats?  Has anyone else seen this kind of thing before?

[sunshineband]

Yes I have !!!! 

You are right that this is likely to be rats who have made the tooth marks at the bottom of the potato

We had rats in our garage last winter and they ate parts of loads of our stored spuds.

The hollow middle happened during growth and the upper brown marks ate rot -- maybe from something like wireworm damage before they were dug, and now those parts are rotting.

Done my best to help - sorry it's a bit of a list 

[ferreter51]

Yes I have !!!! 

You are right that this is likely to be rats who have made the tooth marks at the bottom of the potato

We had rats in our garage last winter and they ate parts of loads of our stored spuds.

The hollow middle happened during growth and the upper brown marks ate rot -- maybe from something like wireworm damage before they were dug, and now those parts are rotting.

Done my best to help - sorry it's a bit of a list 

Thanks for that.  Unfortunately all the damage was done before the potatoes were dug up and not when they were stored.  I can find no trace of underground rat runs or tunnels actually going down in or around the beds.  The Charlottes I dug were affected, but not to the same degree.  Today I will dig up a couple of haulms from the bed of Caras to see if they are also damaged.  It is early for that variety, but I would rather have a smaller crop of decent spuds than one which is heavily damaged.

[sunshineband]

Other plot holders have had damage from rats on growing crops -- I just gave this as an example of when I had seen identical damage. Sorry of this was misleading 

[ferreter51]

Other plot holders have had damage from rats on growing crops -- I just gave this as an example of when I had seen identical damage. Sorry of this was misleading 

No problem.  I have just dug up some Caras and they are badly affected by the chewing, although not by the holes.  A few of the holes and hollow centres have slugs in them, but, of course, slugs can take advantage of the holes made by wire worms.  I don't want to use rat poison, but that may be the only option left.  For slugs I am going to try Nemaslug again.

[sunshineband]

And for wireworms just pick them out as you dig 

Our plot was riddled with them when we first started and now, 18m later, they are few and far between.

That was a lot of digging over and over, and hudreds (literally) of wireworms later.
 
Actually you can also trap them in buried pieces of potato with a stick in so you can find them again aka potato kebabs round here 

[brown thumb]

am i right in saying potatoes are poisonous to rats but not to mice think i have read it some where if thats correct  just think you will have given poor ratty a sore tum if not worse

[sunshineband]

I don't think potatoes can be poisonous to rats, given the amount of damage we had to our spuds in storage last year and one of my plot neighbours suffered with his crop whilst still in the ground 

There is plenty else they could eat and yet they came back for more spuds 

[lazza]

am i right in saying potatoes are poisonous to rats but not to mice think i have read it some where if thats correct  just think you will have given poor ratty a sore tum if not worse

I think it's sweet potatoes that are poisonous to rats.

[loam ranger]

Ive had some of my Kestrel spuds nibbled by rats, also some tomatoes have been got at by rats.
When I checked the traps in the polytunnel this morning there was a rat cought in one of them.  must killed about twenty this year.
Geoff