Agronomy

Root rot complex, namely Aphanomyces euteiches and Fusarium spp., continue to cause a significant economic impact on the pulse industry through the decline in pea and lentil acres.

Currently, best management practices and root rot mitigation strategies available to growers rely almost entirely on crop rotation, where avoiding pea and lentil production for 6–10 years has become common practice. The Root Rot Task Force (RRTF) continues to fund agronomic research testing combinations of different management practices to mitigate root rot complex in peas and lentils.

What we know so far about Aphanomyces root rot:

• It is an oomycete with long-lived resting spores, ten or more years.
• Needs moisture for infection, excessive moisture=severe infections.
• Peas and lentils are equal in susceptibility.
• Inoculum builds over time when favourable conditions and host crops are grown.
• Ideal soil pH range 4.5–6.5 and soil temp 22–27°C for oospore germination.
• Most often and problematic when in combination with other root rot pathogens, Fusarium, Pythium, and Rhizoctonia.
• Seed treatments with limited early season activity provide suppression only.
• Keeping crops healthy – stress-free, pest-free, and with good nutrition can help protect and build crop resiliency but won’t cure an infection.
• There are no natural fixes- the current management strategy is to prevent infections and inoculum from building.
• Rotation is critical. Fields with confirmed Aphanomyces must remove host crops from the rotation for six or more years.