I've already signed up, but am curious about this test.
"Preventative action"! What preventative action? Short of covering
the whole plot with a plythene tent there's not much you can do.

Spray with a suitable fungicide. Covering is unlikely to help as the late
blight spores are already present in the crop and are triggered to germinate
by temperature and humidity.


A suitable fungicide is Dithane 945. I get mine from Wilkinsons. Over
the past few years I have seen it retard late blight's hold on the
crop.

Late blight is now constantly with us and is wind bourne.
Preventative measure also include spacing plants apart to aid wind
flow and thus quicker drying of the leaves. Blight need wet leaves to
infect. Above all, no watering from above, only at the base of the
plant. Removal of infected leaves helps, as does lower soil touching
leaves if it's wet. But as wind bourne, other parts of the plant can
be infected if the weather is suitable. Covering the plants only aids
humidiity, which benefits the fungus. Unless you have many plants
infected with brown patches up and down them, fungicide is the best
bet by far. If one plant is more badly infected than others, it's
worth removing that plant. If the weather stays dry, infection rate of
healthy plant tissue will be prevented.

Fungicide + praying is the best solution

N