Plant-parasitic nematodes affecting wheat yield in the Pacific Northwest

Abstract

Nematodes are roundworms with complex organ systems. They occur worldwide in all environments. Most species benefit agriculture by contributing to decomposition of organic matter and are important members of the food chain. Some species are parasitic to plants or animals. More than 2,000 of the 20,000 identified nematode species are plant parasites. The plant-parasitic species cause estimated annual crop losses of $8 billion in the United States and $78 billion worldwide. Most plant-parasitic species live in the soil and are so tiny they can be seen only with the aid of a microscope.