[Nufan182]

Hello all,

Still rather new to this all so apologies for naiveity.

My Maris Peer and King Edward potato leaves on one of my half plots have died back. On my other plot they seem to be thriving. Does anyone have an idea as to why this is happening?

Nufan

[DD.]

Could be blackleg again.

I say "again" as there's a lot of it about and there are quite a lot of posts about it if you do a quick forum search.

[JayG]

I note that both varieties you mention are susceptible to potato eelworm (PCN) which is therefore another possibility.

Is one of the half plots new to you or have you not grown potatoes there before? The reason I ask is that PCN is very persistent in the soil and it may have been lying there waiting for spuds to be planted for years.

A recent thread mentioning both blackleg and PCN:

http://chat.allotment-garden.org/index.php?topic=107822.msg1211430#msg1211430

[Nufan182]

The plot where the potato leaves have died right back was vacant for about two years. I took it it over last July and just cleared it and didn't chance growing anything in it until this year. There was a huge row of bramble grown through some Terram where my two rows of potatoes are. I don't know if this matters or could have exacerbated things?

[JayG]

They won't have enjoyed the competition but I wouldn't expect that to have killed them prematurely.

You won't have enough clues unless you investigate as per the thread I quoted previously.

[Nufan182]

Good morning JayG,

Thank you for the link to your other post.

I went up to the plots this morning to put your advice to the test.

1) I pulled on the leaves and it did not snap easily and was not noticeably blackened.
2) I dug up a plant that seemed worst of all and to my surprise the potatoes themselves were incredibly good looking, nice and clean with a couple of red 'King Edward' eyes and no sign of any egg like structures. The only thing is the tubers are around a walnut/golf ball size.

I did however pick up in the thread about watering. I must admit I give them a little sprinkling of water every now and then as I understood they absorb water from the ground.  I have not increased the watering for the spuds during the warm weather. I have never fed them apart from a sprinkle of Growmore when planting the seed potatoes. Perhaps it is my lack of watering that has caused the leaves to die back?

I just find it strange that between my two plots one is growing fine and the other is not. This allotmenteering is so confusing at times :s

Nufan

[JayG]

Well that's certainly an better outcome than finding blackleg or PCN! 

You're right - it's impossible to either know everything, or to always be able to repeat your successes even when you think you've finally "cracked it" (Mother Nature always makes sure of that!) 

In your case it could be that your new plot has less water-retaining organic material in it than the other, or is otherwise slightly less favoured as far as water retention is concerned. The competition from the brambles won't have helped either if moisture was an issue.