The Pulse Root Rot Research and Coordination team brings together plant disease experts from across the northern Great Plains and Pacific Northwest. Together, this group combines university research and extension expertise with federal research capacity to address a major disease challenge facing U.S. pulse crop producers.
Root rot is one of the most damaging and difficult‑to‑manage diseases affecting pulse crops such as peas and lentils. It is caused by a group of soil‑dwelling pathogens that can limit seedling emergence, weaken plants, reduce yields, and, in severe cases, cause complete crop failure. Because these pathogens live in the soil, management decisions must be made before planting, often with limited information about disease risk.
The Pulse RAC, launched in 2023 as part of National Predictive Modeling Tool Initiative, is working to give farmers better tools to manage this risk. Our goals are to develop and validate disease risk prediction models that support practical on‑farm decisions and to improve communication and education around pulse crop disease management. To achieve this, the team is developing improved soil sampling methods, monitoring commercial fields to understand how soil pathogens, weather, and management practices affect yield, and building a coordinated Extension and outreach program to deliver research‑based information directly to growers and facilitate the adoption of a root rot risk prediction model.
In the growing season of 2025, Pulse RAC collaborators sampled a total of 32 pea and lentil fields across Montana and North Dakota to detect root rot pathogens in the soil and rate root rot disease outcomes in the field. Soil samples were submitted to the National Agricultural Genotyping Center to test for a panel of nine soilborne pathogens of pulse crops (PRR1.1,2,3-Q). In parallel, we conducted bioassays growing susceptible pea plants in collected field soil to bait out root rot pathogens and rate root rot severity under highly conducive conditions in the greenhouse. From these combined efforts we found that soils where Aphanomyces euteiches was detected also had more severe root rot disease in bioassays (Figure 1). This suggests that the presence of A. euteiches in field soil increases the risk of severe root rot disease under conducive conditions. Soil test such as those offered by the NAGC therefore have the potential to be used as tools for early detection of soilborne pathogens implicated in severe root rot outbreaks. However, soil sampling protocols (where, when, how) need to be refined and validated to ensure reliable and accurate detection of critical root rot pathogens.
In the 2025 growing season, Pulse RAC collaborators sampled 32 commercial pea and lentil fields across Montana and North Dakota. Soil samples were tested for key root rot pathogens, and complementary greenhouse studies were used to measure disease severity under controlled conditions. These efforts showed that fields where Aphanomyces euteiches—a major root rot pathogen—was detected were also more likely to experience severe disease. The finding suggests that root rot pathogens like A. euteiches could serve as indicator species for increased root rot risk. This finding supports the idea that soil testing can help identify fields at higher risk before planting and reinforces the value of investing in improved diagnostic tools.
Building on these early results, the Pulse RAC team has developed an initial root rot risk framework, known as PulSAR (Pulse Soilborne Assessment of Risk). Ongoing and future field sampling will focus on collecting the data needed to refine, test, and validate this model so it can become a reliable decision‑support tool for growers.