Organic Potato Blight Prevention/Cure

[Legin]

I have grown a few potatoes this year and have been luckily blight free. I presume the dry season has helped. Does anybody know of an organic spray to prevent and/or stop potato blight?

I know that my plot can't be completely organic as I am sure some of my allotment neighbours use non organic methods but at least I know *I* haven't used any allegedly harmful products on my crops.

Nigel.

[Legin]

[Tee Gee]

Does anybody know of an organic spray to prevent and/or stop potato blight?

I can't recall if there has ever been such a thing.

In the past we used Dithane 945 but that is now no longer available to the general public, if indeed it is still produced!

[gray1720]

I believe there are "organic" blight sprays, all of which rely on the fungicidal action of copper compounds. How safe are they? Well, this copper mine was abandoned in the 1920s, and this is how much regrowth there has been...

http://news.bbcimg.co.uk/media/images/48589000/jpg/_48589067_linda-loughead-parys-mountain.jpg

Adrian

[Jayb]

No, as Gray1720 says the only shop bought so called 'organic spray' is full of chemical nasties. Some reports around of success with homemade sprays using aspirin or willow infused solution, try googling if you want to know more.

I'm finding some of the recent breeding work with Late Blight resistant potato varieties are giving really good results even in a blighty area. Sarpo Mira and Axona were introduced a few years back and are capable of giving huge crops, though the potatoes aren't to everyone's taste, being on the dry side. Sarpo Mira has the best resistance out of the Sarpo varieties. More recently introduced are several other varieties, I've grown Carolus, Athlete, Alouette (and Sarpo Mira) with very good results so far this year. I've tried Toluca previously, which unfortunately did not have the reported late blight leaf resistance here.

[InfraDig]

Bordeaux ingredients still seem to be available on ebay but it has been been withdrawn for "amateur" use! For some reason it was also regarded as organic.

[Digeroo]

Never could understand how a copper product could be described as organic. 

I have also recently heard about the aspirin.  Have not tried it but sounds worth a go.  We suffer very badly, and no one removes the dead and dying plants.  Though funnily enough the plants survived in all the rain earlier in the year.  Got a good crop of potatoes.

[InfraDig]

I have stuck with first and second earlies. Beechgrove a couple of weeks ago (I think) were talking about cutting the tops off and destroying at the first signs.

[Vinlander]

Never could understand how a copper product could be described as organic. 

I have also recently heard about the aspirin.  Have not tried it but sounds worth a go.  We suffer very badly, and no one removes the dead and dying plants.  Though funnily enough the plants survived in all the rain earlier in the year.  Got a good crop of potatoes.

Anyone who thinks copper in gardening quantities is an effective poison for anything except fungal spores is making a very similar case to the  http://www.dhmo.org/facts.html site - an essential read that warns of the dangers of Dihydrogen Monoxide - which is far more worrying - I try to avoid it in its pure state.

Copper is an essential trace element (especially for mammals - the easiest source is sold as a food additive to improve the health of cattle, pigs etc.). Gardening quantities/concentrations only exceed this if you eat the whole plant (solanine in tomato/potato plants will kill you first) and even then only if you can eat something as incredibly bitter as copper. Just touching your tongue to a coin can spoil your day.

If you can actually see the blue film on a tomato fruit you can polish it off in a second (yes you should wash wrinkly varieties) and you will taste nothing. Compare that with Dithane where the whole fruit tasted of rotting cabbage.

Copper has been used against blight since the 1840s (found by accident) and is still not banned - just unavailable.

There isn't a single man-made 'cide of any kind that's lasted 1/10th as long - they  have all been banned , and everything available today is unlikely to see out the decade - then they will be allowed to sell something new which will also be banned - and so ad infinitum.

None of them were any safer when they came out - and they are just as unsafe now as they will be when they are banned.

Cheers.

PS. I speak as someone who loves science - but there just isn't enough of it about (plenty of imitations though) - the first casualty of conflict is truth, the first casualty of commerce is science.