Bug or Fungus Damage?
I planted a number of my h. striatum seedlings out into my garden this spring. Many have been destroyed over the course of the summer by some sort of disease or bug. Can you help me identify the problem?
The first sign of a problem I see is that leaves start to turn yellow. Close inspection reveals they have rotted at the connection to the bulb and dropped off, despite most of the leaf staying green. Sometimes I see a small amount of what looks like white fungal spores on the soil surface near the bulb.
Digging up the bulb, here is what I find:
The roots and basal plate have been separated from the rest of the bulb, and there is mush in between. However the top of the bulb is still very firm, washed off, it looks like this:
And cutting it in half to look for burrowing insects, I find none:
I have seen no trace of any insect, so I think this is most likely some sort of fungal rot. Only the plants that are in fairly wet soil in nearly full sun seem to display this problem.
Ideas? Is it a fungus? Is there any way to prevent this (aside from the obvious answer of planting in a different spot)?