Hi all

I have noticed what looks like black powder on the underside of my rhubarb
leaves.
It is probably some very small bug-type-thingy. Does anyone know what?

Also on the subject of rhubarb.........

For a few weeks, the stems produced were a good size, maybe 1-1/2" across.
Lately they are far more puny - between 3/4 and 1" across.
Is this usual as the growing season progresses and the large sticks get
pulled?
(I have never drastically reduced the numbe of stems in one hit, if that
makes a difference).

Phil