Dear Charles,
A very late update on what happened to my root crop when I harvested them. The carrots were a complete right off only growing about half an inch long and ended up being put straight on the compost heap. Strangely, the parsnips have been fantastic. Normal size and perfect.
This years seed is in the ground, the carrots are one end of the bed, the parsnips are the other end, the Bacillus Thuringienses is in the potting shed and my eyes will be sharper to spot any tell tale brown patches on the leaves.
best regards,
Anne