Nematodes have a sense of humor too!

Maybe they're trying to tell us something

Nematodes are microscopic worms that live in the soil.  They do various things to different plants but the Root Knot nematodes will cause damage in your carrots.  They will cause forking in the carrot and, if the carrots are left in the ground for a long time like we did, cause large galls like this.  They also attack both the tap root and secondary roots causing them to have large knots or spheres on them.

It doesn't harm the taste of the food and in some cases creates some interesting carrots.  But if you were commercially growing them you wouldn't be able to sell them for top dollar.  

Rotating crops is a great way of preventing the nematodes from one season to another.  Also interplanting with marigolds are supposed to help prevent them.  There are also nematode parasites that you can purchase at gardening stores and online that you release around the base of the plants as part of an Integrated Pest Management system.  Lastly, I saw something on YouTube a while back and if I find it I'll post a link.  Mushroom mycelia actually create tiny nooses that the nematode swims through and it tightens down on it.  Then the mycelia feed off of it and in the process kill it.  

If you have a small home garden you may not worry that much about it.  At least you get some entertainment out of them!

Coop