[Aunt Sally]

These potatoes are on a neighbours plot.

Any idea what the problem is  :?:







The bottom one is a different variety to the top two.

[muddywellies]

It looks like the aminopyralid problem that's in the news at the moment. Here are some pictures:

Contaminated manure


 

[Aunt Sally]

I'm not sure...  The leaves seem to be a normal shape but they are white near the stem and then purple and green at the tips - quite pretty really  :roll:   I don't think they are curling up.  The pots in the bottom picture are collapsing.

[muddywellies]

Yes, those ones in the bottom picture do look particulary sad don't they? I got a massive book out of the library on pests and diseases at the weekend - I'll have a look in that tonight - see if it comes up with anything else. I'm really scared by the whole contaminated manure business :shock: We're lucky enough to get all our poo from our neighbours' horses - but I don't know where their straw comes from  :?

[Aunt Sally]

Thanks Mudy :!:

I fear they could be gonners though.  I'll give him the bad news in a couple of days time if that's what we decide it is  :cry:

[gobs]

Calcium deficiency can cause a lot of weird foliage symptoms in potatoes, if it just the odd few plants, more likely to be something else, can't hurt to try though.

As if just seen something similar, can't remember where... :?

[The Thin Blue Line]

lack of water.

[Aunt Sally]

lack of water.

Will that cause the whitness on the top leaves ?

[gobs]

Yes, the very last picture looks like the wilted ones I raided and need watering for a while.

Water stress is a common cause for Calcium def as in blossom end prob of tomatoes.

[Aunt Sally]

OK thanks, that is probably why the ones at the bottom are collapsing,  but what is causing the white bases to the leaves ?

[Yorkie]

One thought that occurs (though i could be completely off-beam here), is whether it's another trace deficiency?  If calcium isn't being absorbed, could another mineral deficiency cause the whiteness / prevent chlorophyll being used etc?

Would a general liquid feed help, as well as watering generally?

[Aunt Sally]

Thanks for your ideas all  

At least I've got a few ideas for him.  

[gobs]

I know, what you mean, it can be something much more serious all the same, but very hard to tell with chlorosis, as it can have so many reasons.

Is there any other clue at all? Is the stem base healthy and the roots, what are the tubers like?

Any powdery, fungal signs, discoloration on stems, underside of leaves?

Any difference in growth to the rest of the plants, how many are affected, how are they situated, could it be spreading?

Are the leaves dry or brittle? Is it only the  top growth affected or does it spread within the plants?

What are the varieties?

Glyphosate damage in tobacco:

http://www.forestryimages.org/images/384x256/1440082.jpg

[woodburner]

Looking at gobs tobacco pic, I'd put my money on it being glyphosate! :shock:

[Aunt Sally]

That's VERY much like it  :!: