A problem with leeks

 Normally I have no problem with leeks, this year is an exception. They
have grown normally, however when I came to use the first, yesterday ,
on cutting them there are rust colour thin "trails" along the leeks.
These persist most of the way through them. Any ideas as to what the
problem might be and how I can avoid it in the future please?
--
Residing on low ground in North Staffordshire

 "Moonraker"  wrote

I'm afraid to say that sounds like Leek Moth. Did you notice if the leaves
of your leeks looked like they had been at war this year, a bit ragged at
the tips to say the least? You may also notice small net like cocoons on the
leaves.
If it's Leek Moth there is nothing you can do and you will get it every year
from now as it's now got to your area. We have had it for years and find the
plants seem to grow through the infestation, especially if they are planted
a bit later than normal.
I've also had them attack onions at the neck.  :-(
--
Regards  Bob Hobden
Posting to this Newsgroup from the W. of London UK

 
I just wonder if this could be a mild attack of Fusarium Basal Rot

 
Mine have mostly all bolted this year for the first time. I can't
decide whether it's because of the weather or my feeding them while
they were in the seed tray. the feeding worked as I have much fatter
leeks that in years gone by.

Jonathan