Topic: Blight

[brownthumb2]

 I was told potato blight only lives or survives in living  tissue now I've been told it can survive  in soil for up to four years ..What is the right information

[Beersmith]

Well I don't know  the answer to your question, but in my opinion it does not matter too much.

However hard I have tried to do all the recommended things about avoiding blight I have never managed to avoid it any year when we get a lengthy period of warm humid weather in spring or early summer.   But that doesn't happen every year, and in those years blight rarely seems to be an issue.

Now I am a tidy gardener and always try to dispose of diseased plant materials very carefully, but on an allotment field with many plots not everyone will be as  careful, and so as far as potato blight is concerned my philosophy is that chance plays a big part. 

Because it is a fungus disease and spread by spores in the air it can literally blow in from miles away.  It seems more common in summer so I grow first and second earlies only, but otherwise I just trust to luck.

[BarriedaleNick]

I think that the answer is essentially - Blight cannot survive in soil or fully composted plant material. It over-winters in living plant material and is spread on the wind the following year by spores from infected tissues.

However what is unknown or little researched is the question of oospores..

"The presence of new strains in the UK means that the pathogen now has the potential to produce resting spores (oospores) in the affected plant tissues. The oospores are released from the rotting tissues to contaminate the soil. These resting spores have yet to be found in the UK, however, and little is currently known about their survival and their potential as a source of the disease. The investigations into oospores are continuing and more information may be available in a few years." - from https://www.rhs.org.uk/advice/profile?pid=217

[strawberry1]

I had a warning yesterday, in somerset. I stopped dithering and put a couple of tomatoes into a wall greenhouse

[tricia]

I've had another one today. They seem to have changed the name from Smith to Hutton for this year!

Tricia

[Jayb]

Generally I still think

potato blight only lives or survives in living  tissue 

is correct.
However, strains are continually evolving as with the harder hitting 'Blue 13' and I believe strain 'hybrids' are becoming more able to adapt and survive. There's quite a lot of reference to oospores, which is scary stuff.