Topic: Avoiding blight on potatoes?

[Smileyk]

Our potatoes are just coming up and dh was at the allotment last night and was talking to potato man (the resident expert!  ;D ) and he said that with the blight around on the other allotments we should spray now to try and avoid it.  I have a problem with this as:

a). I'd like to be as organic as possible
b). he didn't say what to spray them with!

So what should I do?  Do I leave them or can I spray with something that isn't a "nasty" chemical?

Advice please?

[Barnowl]

There's no cure I'm aware of , but I think Bordeaux mixture is the usual preventative...

http://www.organiccatalog.com/catalog/product_info.php?cPath=61_181&products_id=517

.... I'm sure someone will correct me if I'm wrong.

[Smileyk]

Okay potato / blight experts out there.  Potatoes are through the ground and we've just earthed up.  There has been blight on the other allotments so do I need to spray and if so when?

Any help appreciated!

Thanks  ;D

[tim]

No 'expert' but - Bordeaux mixture IS the only 'non-nasty' - every 2 weeks - every leaf - top & bottom!

And respray after rain!  That's why so many have lost crops this year - there wasn't a day you could spray!

[telboy]

Very true Tim,
Went away for a week in July. Before I left the main crop was upstanding & looked healthy as one could wish.
Came back & the tops were over with the dreaded symptoms.
Took off all the haulms to the ground/left for three weeks/lovely dry spell/ dug up the lot.
After drying/bagged/now inspecting after only one week. Lost 10% already.
Not growing Maincrop next year. (not even the Sarpo rubbish)
After 30 years, this is the only problem I've ever given up on.
There will be others no doubt - the spuds will be replaced by peas. Easier on the back also!

 

[theothermarg]

silly question!!!! going by the fact that it sometimes afects my toms in the G/H
it seems to be airbourn so provided the spuds are put in clean earth wouldn,t covering them with fleece stop? it has anyone tried?
marg waiting to be shot down

[Robert_Brenchley]

The spores are microscopic, and I can't see fleece stopping them. It would be nice and warm and damp imder the fleece too; ideal conditions for fungi.

[theothermarg]

The spores are microscopic, and I can't see fleece stopping them. It would be nice and warm and damp imder the fleece too; ideal conditions for fungi.

mmm yes you make a very good point there. i think my plan next year is to go for 1sts and 2nds put them in early/ dig them up early and try spraying them
marg

[growmore]

I think The most effective spray available to us for blight  is Dithane 945 ..

[tim]

Certainly effective, but less 'organic' than Bordeaux'?

Is it systemic, or must foliage be sprayed over & under?

[dandelion]

Is traditional copper fungicide The same thing as Bordeaux mixture?
http://www.lovethegarden.com/products/pestdisease/murphyfungicide.html
I used it on my toms after first signs of blight and it has been effective so far.

[growmore]

Tim, It isn't systemic and you have to drench same as with bordeaux..

[tim]

Thanks - & less 'organic' than Bordeaux?