Nitrogen-Fixing Nodules on Honey Locust, or not?

I’ve always heard that honey locust does not form nitrogen-fixing nodules like many leguminous plants. Many argue that some degree of nitrogen fixation occurs through a “different mechanism.” This past weekend I was planting a grafted cultivar of honey locust (Calhoun I believe) and ran into the below photos. This plant was grown in containers, so the likelihood of it acquiring nematodes is slim. It appears very healthy with good growth. To me, the mycelium is an indication of good health. Is this wishful thinking, and is this what nitrogen-fixing nodules should look like?IMG_20181110_091849820_HDR



I believe this to be just fungal mycelium.
Typical nitrogen fixing nodules on legumes are a swollen part of the root itself, if active – pink inside

Andy would be a good person to ask about nitrogen fixation on honey locust.

Thanks David. I will reach out sometime this week.

1 Like

I was also under the impression that honey locust does not fix nitrogen.

I have also read somewhere that they do have a root association with nitrogen fixing bacteria. That it is more primitive than the nodule forming relationship and thus does not grow nodules for the bacteria to live in.