Botrytis On Begonia Tuber In Propagator

I thought there might be a problem of too much humidity in the propagator for the begonia tuber which had the stem infected with botrytis. It only took a day or so to show itself.

Although this stem was removed and the wound dusted with yellow sulphur powder, placing it in a too-humid cool propagator was asking for trouble. Still, it was worth a try.

After rubbing off the botrytis with my thumb and adding some more sulphur powder, I opened the vents wide and turned up the heat to about 64 - 70 deg F (18 - 21 deg C). I had hoped to avoid this, since it tends to produce thin shoots, but I'll just have to manage. At least the botrytis seems to have been stopped - for now, at least (botrytis thrives in cool over-damp conditions).