David Hill wrote:
My old "Bible" recommends dusting with sulphur for downy mildew on vines.
I would think if you could leave both ends of the poly tunnel open all the
time and if you could put a fan about 1/3rd of the way down the house and
fit a timer to bring it on for 15 mins every hour to prevent a build up of
stagnant air then you could well avoid the problem.


I do leave both ends open all the time when the weather is warm enough.
The idea of the fan is interesting. Electricity supply will be difficult
but the problems are not insurmountable. I already have a spare fan that
could be used.

--
Howard Neil