- Author: Michelle Leinfelder-Miles
A crop consultant brought in some alfalfa plants and asked if I could help identify the problem. In the field, he was observing stunted plants with shortened internodes and suspected stem nematode (Ditylenchus dipsaci). What seemed different this year is that he was seeing these stunted plants intermingled among healthy plants, and in the past, he was accustomed to seeing stunted plants in groups.
Nematodes are microscopic roundworms that use their stylet, or needle-like mouthpart, to puncture plant cells and suck out their contents. The alfalfa stem nematode lives and feeds in the stems and crown of the plant. Symptoms of infection include plant stunting, shortened...
- Author: Michelle Leinfelder-Miles
I recently received a call from a PCA who had questions about nematodes that infect alfalfa. He had observed stunted crop regrowth after the first cutting and had reason to think that nematodes could be the cause.
There are three nematodes that tend to be the most problematic in alfalfa. Stem nematode (Ditylenchus dipsaci) is a nematode that feeds on above-ground plant parts, unlike most plant-parasitic nematodes that feed on roots. To recap a blog by Rachael Long and Dan Putnam, stem nematode symptoms include stunting, shortened internodes, and even plant death when infections are severe. It is a fairly easy pest to diagnose if...