In article ,
Janet Tweedy writes:
|
| No. Blight is carried only in living tissue.
|
| Why is the new growth at the top apparently unaffected when the lower
| branches and stems are riddled Nick? Does it come upwards from the soil
| then?

I don't know, but some pathogens seem to infect the growing shoots
and others don't. Plants have an immune system of sorts, though it
is very poorly understood, and can sometimes outgrow diseases. At
a wild guess, it is because the new growth is faster than the blight,
which takes hold as soon as the rapid growth stops. Until the plant
is weakened enough that new growth isn't rapid, when it dies.


Regards,
Nick Maclaren.