Topic: POTATO BLACKLEG

[Hugh_Jones]

For over 50 years (on and off) I grew potatoes, and never saw potato blackleg or knew it was.  However, 3 years ago it struck - in a then new variety from a certain firm (and my 3rd year of purchasing potatoes from that firm).  After a strong letter of complaint from me I was informed that the disease was soilborne, nothing to do with the seed, that I was probably overmulching, and that normal 4 year rotation would prevent any build-up.  And I fell for it.

After losing a good 20% of my crop to the disease for the next 2 years, this year I planted my spuds in ground that had never seen spuds before, I used separate tools (sterilised each time) for the plot, ensured that there could be absolutely no cross-contamination from other beds, used no mulch, and guess what? 20% loss of crop to blackleg.

My question is whether there are any of you lot out there who grow spuds regularly, who have never had potato blackleg,  and who can recommend your seed supplier, and if so WHO IS IT PLEASE?

[teresa]

Hi Hugh

dont know if this will help, read somewhere black leg problem the ground is too wet. Have you tried earthing up as soon as they are planted that what hubby did.
Sorry cannot help with seed supliers.

Teresa

[Hugh_Jones]

Nothing to do with wet ground teresa.  My soil is a dry one at the wettest of times, and this last summer  particularly I have had the greatest difficulty in supplying enough water to maintain growing conditions. And it`s no different than all the donkey`s years that I`ve grown potatoes without any signs of any blackleg.  No, I`m absolutely convinced that it arrived with some dodgy seed potatoes, and if the supplier is getting them every year from the same grower, then they will continue to be dodgy.  The only way I can be sure is to try some from a fresh, safe supplier and grow them in a fresh piece of ground.  

That`s why I want the names of suppliers recommended by  people who`ve never had the problem.      Doesn`t seem a lot to ask, does it? So why is everyone so backward at coming forward?

[teresa]

Hi Hugh
Try this site.

Scottish Agricultural Science Agency - Internet Site
Home | Plant Variety Testing | Potatoes ... More information. CONTACT US ... DATABASE ... DISEASE TESTING ... FORMS ... NEW VARIETY ... BlackLeg ...
| From www.sasa.gov.uk | More results from this site

Good Luck Teresa
what do you know about Manchester Rhubarb?

[gavin]

Hi Hugh - I'm not much help, as I've never seen blackleg.  Which might just be a good sign?

I copied and pasted this from the HDRA page

"The main source of infection is the planting of infected tubers; even certified seed can contain a certain amount of blackleg. The disease can also survive in the soil, and in potato debris, but these are unlikely to be important sources of infection. The disease is unlikely to spread from plant to plant during the life of the crop. Healthy tubers can be infected from diseased ones which have rotted in the soil, or in store. Some infected tubers will carry the disease without showing any symptoms."

And I get most of my seed potatoes from the Chase Organics catalogue on http://www.organiccatalog.com/, the rest from the local potato day.  

All best - Gavin

[Hugh_Jones]

Thanks Gavin.  The Chase Organics Catalogue it shall be from now on.

Just in case you may ever get it, the signs are a general yellowing of the leaves, margins of upper leaves roll inward, the stems darken in colour, collapse and rot.  The only thing you can do is dig out the affected plants and burn them, but of course you have to get up every single tiny tuber off the plant, and this inevitably means you damage the roots of the plants on either side and lose even more of the crop.

[tim]

- don't  forget 10% discount for HDRA MEMBERS? - Tim

[Hugh_Jones]

Thank you for your belated contribution, tim, although I`m quite sure that you could have answered the question all on your own if you`d come in a bit earlier.