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Nematology Research

The University of Idaho nematology research program delivers statewide teaching, research and Extension programs that conduct nematode and disease diagnostics, develop economical control practices and apply practical knowledge to solve the widespread issues caused by nematodes across Idaho agriculture. Faculty and support personnel are located on the main Moscow campus and at research and Extension centers in Aberdeen, Idaho Falls and Parma — conducting research in the laboratory, greenhouse and field.

The first research program focused on nematodes in Idaho was established at the U of I Parma Research and Extension Center in 1981 under the leadership of Professor Saad Hafez. Since then, the program has reported a total of 32 genera and 117 species of nematodes on 31 unique types of host plants from 21 Idaho counties.

Current Research

Nematology research at U of I studies the biology, behavior, ecology and preventative methods for various species of nematodes to mitigate their impact on Idaho agriculture with an emphasis on those affecting some of the state’s most iconic commodities like small grains, sugarbeets and potatoes.

  • Over the past decade, Professor Juliet Marshall’s work has focused on screening wheat and barley varieties for resistance, susceptibility and tolerance to cereal cyst nematode (CCN) and lesion nematodes. While her research indicates the co-occurrence of CCN and lesion nematodes, continued research is needed to determine the synergistic effects of the two. During this work, the team discovered the presence of a new nematode in southeast Idaho which inspired studying a broader region and the continued screening of newly bred varieties of small grains.
  • Similar work is being conducted among sugarbeets and potatoes to prevent, contain and eradicate nematodes that threaten production of these top crops. U of I is a pioneer in trap crop research with Hafez introducing the use of oil radish as a tool for sugarbeet and potato nematode management while Associate Professor Louise-Marie Dandurand is pioneering research with the use of litchi tomato as a trap crop for potato nematodes.
  • Oil radish has been found to reduce nematode populations by 92% while increasing sugarbeet yield by nearly 25% and potato yield by 16%. The use of oil radish reduces the percentage of potato acreage once rejected due to nematode damage from 4% to 0.1% annually. The use of litchi tomato as a trap crop to control pale cyst nematode (PCN), the most-damaging nematode for Idaho’s potato industry, resulted in a 95% reduction in PCN populations. Both methods contribute to the reduced need for chemical fumigation in potatoes and sugarbeets.
  • Dandurand and her international team of researchers are world-leaders in PCN containment and eradication which was underscored by a successful $6.9 million USDA Specialty Crop Research Initiative grant. The four-year project aims to provide growers with the best management practices for controlling infestations of both root knot and potato cyst nematodes in potato fields and arming producers with improved diagnostic methods, management models, development of resistant varieties and novel nematocidal chemistries.
  • Professor Edwin Lewis and his team conduct research on group behaviors and interactions among insect-parasitic nematodes, investigating how these behaviors affect the use of resources and competition. Their work focuses on understanding how nematodes form and maintain groups, communicate with each other and coordinate activity. His studies have revealed that plants can influence interactions between nematodes and aboveground herbivores that share the same plant. He also examines how nematodes decide which plants to infect and utilizes nematode community structure to assess soil health.

Supporting Growers and Industry

Researchers work with growers and industry representatives to provide new and improved tools and information to ensure Idaho producers have the best resources to manage nematodes.

  • Diagnostic services — the Parma-based nematology laboratory conducts diagnostic services for growers, eliminating the need to send samples out of state. Research informs the continued improvement of these diagnostic services.
  • Variety development — research in small grains, sugarbeets and potatoes informs breeding practices for researchers to develop varieties of crops that are resistant or less susceptible to specific species of nematodes.
  • Trap crop education — specifically the use of oil radish and litchi tomato as many nematodes are problematic for a variety of crops and crop rotation may not reduce populations.
  • Improving nematicides — purifying litchi tomato, which is toxic to many nematodes, for novel nematicide production.
  • Modeling to develop new resources — like tools to manage an infestation and predict how that will impact yield.

A number of public-private partnerships have evolved from U of I’s nematology work in addition to the regular work with industry evaluating potential nematode control products. Current projects with industry include:

  • An effort to test the efficacy of mustard seed meal extract on effectively killing PCN in field conditions.
  • Developing a nematode pheromone to improve the abilities of insect-parasitic nematodes to find, infect and kill insect pests.

By the Numbers

  • Currently, 20% of a producer’s production costs go toward management of invasive nematodes.
  • It is estimated that plant-parasitic nematodes cause 12% of crop losses globally, which means $157 billion annually — of which, the US share is $5.8 billion.
  • The pale cyst nematode and golden nematode can reduce potato production by as much as 80%.
  • For every $1 of investment in the U of I nematology program, the Idaho agriculture industry is expected to benefit by an estimated $53.
  • The benefit of Professor Hafez’s program to Idaho potato and sugarbeet growers is estimated at $18.5 million and $13.9 million, respectively.
  • Total annual net benefit to the Idaho agriculture industry from the U of I nematology program is $29.7 million.

Our People

  • Louise-Marie Dandurand, Associate Professor
  • Saad Hafez, Professor and Extension Specialist
  • Edwin Lewis, Professor, Co-Director of the Institute for Health in the Human Ecosystem
  • Juliet Marshall, Department Head for Plant Sciences, Professor, Idaho Wheat Commission Potlatch Joe Anderson Endowed Chair for Cereal Agronomy


University of Idaho

Physical Address:
E. J. Iddings Agricultural Science Laboratory, Rm 242
606 S Rayburn St

Mailing Address:
875 Perimeter Drive MS 2329
Moscow, ID 83844-2329

Phone: 208-885-3776