
Choose seed that is good quality and disease-free. Best practice is to use seed treatments to manage seed and soil-borne diseases to protect against early infection by Aphanomyces, Fusarium, Pythium, and Rhizoctonia
Developed by the Root Rot Task Force with members from Alberta Pulse Growers, Manitoba Pulse and Soybean Growers, and Saskatchewan Pulse Growers
The need for a Pulse Root Rot Network (PRRN) was identified in 2021, when Canada’s pulse grower associations developed a National Pulse Research Strategy to identify research priorities and coordinate pulse research across Canada. In this strategy, controlling root rots in pea and lentil, in particular Aphanomyces and Fusarium spp., were identified as a top priority. The PRRN was launched in 2022 by the western Canadian pulse crop commissions (SPG, APG, MPSG) to catalyse a collaborative approach to root rot research and management focused on agronomy, breeding, and pathology in peas and lentils.
Root rot complex causes significant yield impacts and limits production areas for peas and lentils. Aphanomyces eutiches, Fusarium sp., and other fungal pathogens, dominate the root rot complex. Profitable and sustainable pea and lentil production require us to eliminate this risk. The Root Rot Task Force has developed a strategic action plan to address the challenges pulse growers face due to root rot complex. Our mission is to eradicate the risk of root rots through a coordinated, collaborative effort across the pulse industry.
CONSIDERATION | HIGH RISK | LOW RISK |
---|---|---|
Soil test for Aphanomyces | Positive test result | Negative test result |
Environment the last time or times peas/lentils grown | Above average moisture (wet) | Below average moisture (dry) |
Symptoms last time peas/ lentils grown | Patchy to whole field affected; late season lodging | No symptoms; healthy field |
Action | If one or more checked above = HIGH RISK. Do not seed peas or lentils into the field. Choose a different field, wait until soil test is negative, or remove peas/lentils out of rotation until you have a confirmed negative soil test or 8-10 years depending on growing region and other risk factors. | Consider intermediate risk factors |
CONSIDERATION | HIGH RISK | LOW RISK |
---|---|---|
Field conditions | Heavy texture with poor drainage Field has compaction issues | Lighter texture with good drainage No compaction issues |
Number of times peas/lentils grown in past 20 years | Greater than 5 times, or unknown | Fewer than 5 times |
Last time in peas or lentils | Less than or equal to 4 years | Greater than or equal to 8-10 years |
Action | If the majority of checks in this column then consider the field as Intermediate Risk – consider Minor Influencing Factors before planting peas or lentils into this field. | If the majority of checks in this column then consider the field as Lower Risk – consider Minor Risk Factors to help reduce potential infections and severity. |
CONSIDERATION | HIGH RISK | LOW RISK |
---|---|---|
Rotation – crops included | Limited diversity (two year rotation) | More diverse (three+ year rotation) |
Rotation – managing Fusarium | High residue levels infected with Fusarium from previous crop (cereals) | Low or no Fusarium infected stubble from previous crop |
Weed control – presence or absence of susceptible weeds (alternative hosts) | Weeds have been out of control on the field with high levels of host weeds | Field is relatively weed free going into pea/lentils |
Action | Intermediate Risk – Consider Management Decisions (Table 2) prior to seeding to address minor influencing factors where possible or plan to seed peas and lentils in a different field. | Low Risk – Field is low risk for Aphanomyces infection but no guarantee of no risk. Consider Management Decisions in Table 2. |
Choose seed that is good quality and disease-free. Best practice is to use seed treatments to manage seed and soil-borne diseases to protect against early infection by Aphanomyces, Fusarium, Pythium, and Rhizoctonia
Varieties can differ in the susceptibility to root rot pathogens; choose varieties with improved resistance where available. Check seed guides for Fusarium ratings
Toot rots impair a plants ability to access nutrients. Use a balanced fertility plan to ensure nutrients are available and easily accessible. Know the safe rates of seed placed fertilizer to minimize stress to young seedlings.
Address any compaction in the field and do not move heavy equipment across the field if it is higher moisture (including rolling under wet conditions). Choose fields with good drainage or lighter land for planting peas or lentils
Check out the Aphanomyces Risk Evaluation App (AREA) for more information
Resources for your specific province can be found at saskpulse.com, albertapulse.com, and manitobapulse.ca
Root rot pathogens can have a devastating impact to plant performance and are a significant threat to pea and lentil production with substantially reducing yields of up to 70% in peas in high root rot conditions. Root rot pathogens are seed or soil-borne diseases and can infect the plant at any stage between germination and maturity, and at any part of the root system up to a short distance above the soil.
Root rot causes a brown discolouration of the roots and the plant is unable to develop a strong root system. With this disease, the plant wilts, there is reduced plant growth, yellowing of leaves, root decay and premature death. As the damage is initially done at the roots, root rot may not be immediately obvious. Root rot may also reduce the pea or lentil protein content as the pathogen attacks the nodules. This impacts the plant’s ability to fix nitrogen and prevents normal nutrient and water uptake.
The root rot pathogens include Aphanomyces euteiches, Fusarium spp., Pythium spp., and Rhizoctonia solani. These can also be considered as a root rot complex where more than one pathogen is present. Aphanomyces euteiches and Pythium spp. are organisms that belong to a group of fungal-like root pathogens and are considered water molds. They do particularly well in saturated soils.
Aphanomyces was first reported in Manitoba in 1997 and into the early 2000’s. It was only positively identified in Saskatchewan in 2012, and in Alberta in 2013. It is likely, however, that root rot pathogens have been present for much longer as it is native to our soils.
Aphanomyces has had the greatest negative impact on yields due to difficulty in managing the disease. The length of time that the oospores (resting spores) can survive in the soil, the absence of genetic resistance, and the lack of effective control measures makes it the most damaging root rot pathogen. Fusarium spp. and the other pathogens can also work with Aphanomyces to increase the severity of the disease. Fusarium is the most common root rot disease in pulses and can also infect cereals and other rotational crops, however, its impacts are less severe as there are pea and lentil varieties with partial resistance and some available control measures. Pythium spp., and Rhizoctonia are also less worrisome as both can be controlled by certain seed treatments.
Research efforts since 2012 have increased our understanding of root rot pathogens, their life cycle, virulence, diagnosis, and the interaction between the plant, the pathogen, and the environment. More work is needed to understand what factors could potentially impact the survival of the resting oospores, novel management strategies and control options, and breeding of resistant or partially resistant varieties.
The best route for controlling root rot at this time is prevention and knowing the root rot risks. Know your field’s history; test your soil; manage the crop rotation including limiting the frequency of susceptible crops; utilize best soil management practices (good nutrition, and reduce compaction). Maintain good field records. How well did the crop do last time? What were moisture levels then and in subsequent years? Were there patches of diseased and dead plants in the field? Did these patches coincide with water pooling areas and waterways?
Figure 1. Aphanomyces infection is characterized by (1) yellowing and wilting of shoots, (2) pinching of epicotyl, stopping abruptly at soil line, (3) lateral roots with watery and honey-brown decay. Fusarium infection sees (1) shoots remaining healthy, (2) blackened tap root, starting at seed attachment, (3) healthy lateral roots. Source: Syama Chatterton, Agriculture and Agri-Food Canada
Resources for your specific province can be found at saskpulse.com, albertapulse.com, and manitobapulse.ca
APG, SPG and MPSG recognized the interest in eradicating root rots in Western Canada during development of the National Research Strategy in December of 2021. In response to common interests a Root Rot Task Force was established with members from each of the prairie pulse crop commissions. The first initiative of the RRTF was to bring together researchers, agronomists and industry from across Canada through participation in the first Root Rot Rodeo (RRR) event to form the Root Rot Network (RRN) in June of 2022. The outcomes from this event were the basis for the the current root rot strategy that focuses not only on research priorities but a coordinated effort on funding and communications.
Pulse Root Rot Network: Network of researchers, agronomists, industry partners and stakeholders invested in root rot research.
Root Rot Task Force: Collaborative crop commission team of SPG, APG, and MPSG members driving coordinated efforts across industry, academia, and government.
Universal root rot strategy: Unified approac to addressing existing barriers to agronomic tools and addressing knowledge gaps in root rot research
Provide growers with recommendations and tools for effective on-farm root rot risk management and assessment.
Specific Target Outcomes
Ensure robust genetic resistance to root rot pathogens is available to growers.
Specific Target Outcomes
Deepen understanding of biology, pathogenicity, and interactions of the root rot pathogens in pulses.
Specific Target Outcomes
Develop funding mechanisms established for root rots that are collaborative, coordinated, and accessible.
Establish reliable funding capacity and streamlined processes for research.
Specific Target Outcomes
Ensure human, capital, or monetary resource limitations do not hinder advancement of root rot research.
Specific Target Outcomes
Provide unified, science-based messages on root rot recommendations and information for growers, agronomists, and industry.
Develop cohesive, coordinated updates of recommendations and root rot extension across provinces and disciplines.
Specific Target Outcomes
Establish a reputation for gold standard processes in root rot research and extension.
Specific Target Outcomes