Charles
I decided to grow Sturon onion from sets this year and obtained 150-odd from OGC and planted them in modules on 23rd March to get them firing before planting out late April to try and avoid the allium leaf miner.
Now it looks as if some sort of fungus is developing on the outsides. In the picture, the two middle sets appear to have white growth and quite a lot of the 150 appear to be developing similar.
1) Is this white rot?
2) As they have been in my lean to out of the rain since planting, could I have done anything to introduce the disease?
3) If it is disease, is it most likely that these sets were already infected?
Never having seen this before, I withold judgement as I am not sure of my ground.
But supplying infected onion sets would be really unacceptable, particularly if white rot hangs around, is difficult to eradicate etc.