[3759allen]

i've noticed that a couple of my potato plants have some poorly looking stems. only half the stems of the same plant seem to be effected, the other half looks healthy. all the rest of the plants also look fine.

have any of you got any ideas what it is? should i cut the effected stems back to ground level and tip them?

[fatbelly]

I get a few of my Spuds do this every year.
Pull them out because in my experience they infect others.
I don't know what it is thou.

[mumofstig]

Can't really tell from the pic - but if the stems have gone brown/black nearer the soil - then it's blackleg.

As fatbelly says, pull the plant and lift any spuds that have formed (you can eat these) before it spreads along the row.

[3759allen]

i have got another couple of pics.

it looks like the stems are totting from the top downwards. there looks like small fresh leaves towards the bottom. the stems that are effected seem to go like mush.

blackleg or something else?

any idea what causes this and what i can do to prevent it in the future?

cheers.

[mumofstig]

Blackleg - I think it comes in with the seed and damp weather makes it more likely. Good drainage helps.
 
Apart from lifting to stop the spread, and crop rotation, I don't think there's anything you can do to prevent it.

[3759allen]

the soil is very well draining, it has been a bit on the damp side and a topsy turvy spring so hopefully just that. the seed i got this year didn't seem as good as usual so maybe that has something to do with it.

do i have to lift the crop or can i get away with cutting the foliage back to below soil level?
 

[3759allen]

just looked on rhs site and it seems that if the tubers aren't effected yet they will rot if left so i will be lifting this afternoon.

[mumofstig]

Yes, lift them - but if they are clean you can still eat them.

[3759allen]

lifted and plants in a bag away from the bed ready to go to the tip.

just hope the rest are ok. i think it may have been dodgy seed as there's been quite a few that have come through very late and small or not at all despite chitting them. i've never had a failure or problem with potato's since i started 3 years ago. i will be a bit more selective with my seed next year and hope the same will not occur.

[jaydig]

This season I've had gaps in my rows of potatoes too.  Several different varieties, so I can't blame it all on one particular type, but they have finally started to come through.  Like yours, all of mine were well chitted before planting, so I don't know what the problem has been.

[3759allen]

at least it's not just me.

[AnneB]

I had five tubers of Ambo maincrop sourced via our local potato day.   All have succumbed to blackleg.   

The remaining varieties,   Colleen, Red Duke of York, Sharpe's Express, Charlotte, Osprey and Pink Fir Apple all seem to have escaped.   Let's hope they avoid the blight!!

[18Forts1999]

Have had a problem with Lady Christal this year. Many haven't come through and those that have are on the small side with wizened leaves. Have dug some up and the tubers aren't affected but am at a loss as to what the reason is. The soil is well drained, although clayey base, but I did put on some top soil later last season with plenty of muck.

[JayG]

I've had the odd case of blackleg in more than one variety of spud over the years - once the stem is clearly affected and wilting you will find it will easily pull out of the ground as it will be rotten at the base.

Important to dig up and destroy (not compost) affected plants so they don't infect others (then disinfect the fork you dug them up with.)

Rocket were pretty problem-free last year, but were disappointing in taste, so I'm growing Lady Chrystl again this year despite having problems with it in the past, notably with potato eelworm (PCN) of which there are two types, one of which it has good resistance to, the other it doesn't...

Some look good, some look distinctly weak, some have been knocked back by slug attack (unusual on my dry sandy soil.) Any plant which continues to look sickly will be dug up as it's probably succumbed to PCN and is unlikely to produce anything more than a few pea-sized 'tubers.'