Topic: Carrot fly...

[Gordonmull]

It was all going so well.

Despite having fleeced the crop I seem to have a minor infestation. Found a grub in one today along with the distinctive little tunnels I remember so well from last year. Looked like the second one I pulled had had a bit of a nibble on it too.

My setup is as follows: 9 rows of carrots, with fleece over three rows, then another length of fleece over the next 3 etc. I have only been harvesting from under one fleece, one was removed for thinning and replaced. I left the other fleece in place and didn't thin since it was too much of a nightmare untangling all the leaves and getting the fleece back on.

What to do now? Do I pull the lot? Is it worth checking the crops under the other two fleeces or is that just tempting fate?

[ed dibbles]

Ah you have unwittingly set up an experiment  :) If the ones you thinned have some carrot fly damage and the unthinned ones don't you have proof it's the thinning out that attracts the fly.

Then you can act accordingly ;)

Last year I grew the carrots under fleece being meticulous with replacing the fleece immediately after thinning the carrots. That worked well with no damage from the pesky fly.

This year I'm trying a different tack - leaving the annual weeds to grow with the carrots (the weeds disguise the smell of the  carrot foliage). Thin initial sowing but no thinning after other than harvesting the roots.

I have been pulling out the large sow thistles but all other weeds are left in place.

So far no carrot fly damage on any of the carrots harvested so far :)

As with many of these things it's a case of trial and error.

[Linnea]

my gut feeling would be to leave them be. it sounds like mine in that when I've taken the fleece off to weed/thin I've let a fly in so unlikely to ruin the whole crop but got to some.
At the end of the day is there anything to loose by leaving them and maybe picking one or two extra each time to make up for the nibbled ones?

[ed dibbles]

Quite so - Likely to be minimal damage if they have been fleeced almost all of the time.

You may find the damage in in a relativaly localised place anyway but when harvesting pick one or two more just in case.

[small]

I always seem to get some carrot fly, worse some years than others....but I just cut out the tunnelled bits and use the rest - after all, I'm not trying to grow supermarket appearance carrots, just carrots with taste.

[Gordonmull]

There was a period they were unfleeced - from June until Mid-August, when I thought the CF wasn't supposed to be about...it seems I was mistaken. I pulled all of the carrots from under the part I was harvesting from - they were spring sown so most are a good size anyway, just in the ground to keep them fresh. Just over half were damaged. I'll chop out the bad bits cut them up and freeze them for convenient soup, stew and mince material.

Based on this (and curiosity piqued by Ed's experiment) I took six carrots from under the other two fleeces, all June sown. Two were damaged, coming from the bed I didn't thin  ???  ::) Interestingly, (to me anyway) it was the larger carrots that were mostly affected with the few little 'uns mostly escaping. [EDIT - I meant 6 from under EACH of the two fleeces]

I'm far more worried about suitability for storage in sand than I am about appearance. Freezer space isn't that huge.

My June sown will just have to live with it since they are only fingerlings yet. 10% infestation I can live with but I'm hoping the grubs will just remain in the carrot they infected and not travel too far. Anyone know?

[laurieuk]

Do remember that if you have had carrot fly in that area before the grubs overwinter in the ground so regardless of what you do above the ground you may get infected from below. I asked the RHS about the thing of putting up a barrier to stop them flying in as they can only fly at a low level but as they say you may trap them inside the barrier . I now grow in containers standing up too high for the fly to get at.