Blight potatoes

Are there different kinds of blight - some just caused by the weather if the potatoes themselves are okay is there still need not to plant agian for seven years? If so what do commercial growers do?
I am in a bit of a fix as I was reclaiming land from gorse etc. and htought that the easiest way was to grow a lot of potatoes. So have I really messed up?
Is there soemthing I can put in the earth to make it better after having the blight? Also have chocolate spot on broad beans which I grew in a raised bed in a part of the garden which had never been cultivated before.
thanks for any advice.

 

lapod, as far as I know there arn't different kinds of potato blight, I assume that it is the same one that attacks potatos and tomatos.
As for stopping it next year, it may not strike if the weather is dryer.
I get it on toms, and this year I've sprayed a couple of times with fungicide as a preventative, up to now not a sign, but I reckon it will rear its ugly head in late sept/ oct time when things get really damp all day.

When I used to grow Broad beans I always got chocolate spot, but never was it a real problem.
Seem to remember it being put down to a lack of potash, but never proved it to myself one way or another.

 

Thanks Pete,
All the potatoes are edible and look great except fo the original which was all squishy and decayed.
yes and the broad beans taste fine too.

Thanks for the reassurance.

 

There is only one potato blight - phytophthora infestans. It propagates through water and is a water borne mould - it is not a fungus! Its behaviour is well understood http://www-biol.paisley.ac.uk/bioref/Chromista/Phytophthora_infestans.html. Predicting blight is the tricky subject. A period of time must elapse whereby both temperature and relative humidity are maintained at a certain level (a Smith Period). Once the conditions are met, 7-10 after is the blight risk period. Your choice is to "taget spray" to protect them, buy a resistent variety (Remarka), or lose them. There is no need to spray as a matter of routine and resistent means that - not invulnerable! My lean to green article has further links to information on the problem http://www.plotkeeping.talktalk.net/page3.html

 

TIG, I was under the impression that blight was fungal, as fungicides seem to work on it.
What exactly is a mould?

 

I agree pete, I always thought blight was fungal that`s why you treat it with copper fungicide. David.

 

Its an airborne fungal infection.

 

It can also overwinter in the soil. David.

 

True, but not so common.