Fall Beet Fail

I've grown gorgeous spring and fall beets for the last three years, including this spring.  This year fall beets have been a total failure and the carrots and spinach aren't much better.  Beet seeds went in about 5 weeks ago...with a scoop of home-made compost per square...about half the seedlings rotted right at the soil surface, and the other half rotted below the soil.  Maybe there was a pathogen in my compost...and the 98 degree temps here probably don't help.

Beet seedling rotted right at the soil level...and the stem above ground laid down and grew flat along the soil for a couple inches before the leaves start...not upright like a nice healthy beet.


At right, a typical failed, stunted, floppy beet seedling rotten right at soil level...at left, beets with decent greens but rotted deformed main root below soil level...never had this problem before. 

Some years are good for beets, some not so much. Also I think there are specific soil requirements to get the beet to bulb up.... boron maybe?

Also, beetroot can take upwards past 90 days to get a mature bulb.
http://myfolia.com/plants/90-beetroot-beta-vulgaris

I sent the pics to our local Master Gardener program at the county extension office...they said it was Damping Off.  Instead of messing with purchasing a fungicide I think I'll just buy bedding plants for those raised beds and reseed beets in another area.