Hi Gerry,

thank you for coming by our office the other day and providing good photos to accompany your question!

After further inspection of the carrot in the photos, it looks like a symptom of root-knot nematode (Meloidogyne hapla) based on the galls.  These galls typically form on the fine feeder roots on carrots, but can expand; larger galls are usually associated with higher nematode population density. Other symptoms of root-knot nematode damage on carrots can include forking, hairiness, stubby roots, and stunted growth.

Parasitic nematodes in general can be difficult to manage and nearly impossible to eradicate, however here are some recommended cultural control methods that can help in root-knot nematode population suppression and reduction:

Crop rotation - although M. hapla has a very broad host range, monocot crops are not included, so planting corn, asparagus, or small grains in that bed area for a season can reduce the population. Although there are other crop cultivars that are labeled as nematode resistant, it is not for this specific species.

Weeds - Managing weeds is an important control strategy, as they can also serve as hosts.

Cover crops - Research has shown that planting certain brassica cover crops can work to suppress nematode populations.

Biological Control - Adding compost and increasing soil organic matter to promote stronger microbiological activity in soil can boost competition against nematodes.

Do not compost infested plant material, and be mindful about moving infested soil to other growing areas.

Produce with nematode galls are still edible, although maybe not preferable, and your instinct to cut the tough galls out is a good one!

Fall is a good time to sample and test soil for nematodes ahead of the next growing season, and is recommended to guide management decisions. Please reach out to our Plant Diagnostic Lab for details on sample collection and analysis - https://extension.unh.edu/agriculture-gardens/pest-disease-growing-tools/plant-diagnostic-lab

For further information, here are some good Extension-based resources:

UMass Amherst - https://ag.umass.edu/vegetable/fact-sheets/root-knot-nematode

U. Maryland - https://extension.umd.edu/resource/root-knot-nematodes-vegetables/

Please let us know if you have further questions!