Home

What Are Nematodes?

Nematodes are typically tiny roundworms that thrive in virtually all environments on earth. They are the largest group of multicellular species in the animal kingdom. Some species are parasites of plants and cause economic losses in a wide variety of food, ornamental and industrial crops. Other species however are beneficial: they may help in the recycling of soil nutrients, or may feed on pathogenic fungi, bacteria, insects or other nematodes. In addition, nematodes are one of the favorite model organisms in studies on molecular genetics. This workgroup is mainly focused on developing and extending information about plant-parasitic and beneficial nematodes.

Sting nematodes feeding on a corn root

root-knot nematode damage on carrots

California Nematology Information

Plant Parasitic Nematode Thresholds/Damage Levels

Crop damage is typically related to the density of plant-parasitic nematodes at seeding or planting although plant response as well as soil biotic and abiotic factors may modify the crop injury extent. A Nematology Workgroup project compiled crop damage thresholds for some important nematode pests in California.

Meeting Reports

Annual Work Group & Work Shop Meeting Reports

Nature of a beet cyst nematode population suppression unraveled

Tiny parasitic roundworms (nematodes) that typically feed on underground plant parts are responsible for an estimated $10 billion in crop damage in the U.S. Nonchemical management of these pathogens has progressed slowly. No biological control product against plant-parasitic nematodes has ever received California EPA registration. The lack of understanding of microbe-nematode interactions is perhaps the greatest impediment to significant progress. Nematode-suppressive soils are soil sites where conditions for nematode-caused crop damage are present, but where such damage does not occur or where it occurs at a much lower level than expected. These are often sites where biological control occurs naturally and plant-parasitic nematode populations are typically maintained below the economic threshold.

Read about: Nature of a beet cyst nematode population suppression unraveled | View Other Stories