Help! potato blight!

[Jardiniere]

I know there is probably stuff on this somewhere in back threads but need advice!!
I have planted potatoes for the first time in this garden and they almost all have died back with black leaves, slimy stems etc etc.
I am certain it is blight and i have already pulled out the earlies but not thoroughly dug through (Sarah Raven says to leave the pots in ground for a few weeks).
I now have to do the same to my second crop.
There are a few odds and ends at the other end of the garden that do not appear to be blighted yet so i have sprayed them and all my tomatoes with bordelaise mixture.
will burn the vegatation as soon as it is dry enough.
QUESTIONS
1.What causes it? It has been incredibly wet here, the wettest May/June i have known in 16 years of coming to this house. (But first year i have properly gardened here)
2.Will i get it every year?
3. What can I now plant in the space left by the potatoes? the space will be available by end of June.

[big digger]

Hi Jardiniere
I am also in France and was told when I planted all my potatoes - that there was blight last year - I have sprayed also Bordeaux mixture as soon as the haulms appeared and still spraying today - I have used the advice from the John Seymour Self sufficiency book - he cuts the infected tops off with a sharp knife and destroys them by burning - leaves the potatoes in the ground for at least a fortnight after wards - preferably longer, so they dont come in contact with blighted soil.

it is caused by spores which settle on the leaves at first causing dark brown patches then going slimey.
I am no expert but have been very wary of this and sprayed according to advice. If you planted early I should say your potatoes must be nearlyy grown so if you cut off tops and leave you may be lucky to save some of your crop-You must make sure after this infection that every single potato is out of the ground as they harbour the spores that continue til following year. best of luck let me know how it goes
big digger

[TPeers]

If you are not certain that you have the halms out of the ground the blight will run to the spuds which turn black and slimy. You must clear the ground of all the infected material and dispose of it by burning or black sack and dump - it must not be composted!

The only recourse you have is to choose blight resistant varietys in the future - this years heavy rain in May seems to have triggered blight early. Watch out for you tomato crops as they can also be affected.

As to what you can follow with, I don't think there is too much of a problem, follow the rotation you had planned but do clean the ground carefully before hand.

Terry

[Protea]

I'm assuming, that as you're in France, its been a bit warmer than it has been in the UK for the past few weeks!

Warm and wet weather are ideal conditions for the spores of Phytopthora infestans (late potato blight) to germinate, and infect growing tissue (of potatoes, tomatoes and other members of the solanaceae family). Alternatively, with it only being June - it may be early blight (Alternaria solani), symptoms are similar but caused by a different pathogen. Treatment is the same however.

Bordeaux mixture is only effective as a preventative spray - you need to apply it before the infection occurs (when conditions are conducive to attack) as it has no curative effect on the disease.

Its likely that you may experience the disease in future years - you could try growing some of the blight resistant varieties (Sarpo.....), or just grow earlies which should escape the main late blight season.

info on early blight: http://www.gardenorganic.org.uk/pdfs...rly_blight.pdf
Late blight: http://www.gardenorganic.org.uk/pdfs...ate_blight.pdf

[Jardiniere]

Thank-you for the advice.I have pulled out all the haulms but cant burn them yet as its been too wet and also we arent allowed bonfires here between may and sept so i am going to have to burn them bit by bit in my oil drum with the lid closeby and hope no one reports me.
some of the tomatoes do seem to be affected but others arent - either because ive got them with the bordeaux or they are resistant varieties (need to check my seed packets)or they just arent showing it yet.
NEXT YEAR - i have a piece of uncleared land which i hope to clear by next year -so the potatoes will go in there next year - and i thought i could grow the tomatoes in pots and bags etc on the terrace away from the garden soil.
Does that sound right? anyone?