There are currently no control options for Aphanomyces. Several best management practices (BMPs) have been identified that help increase a plant’s ability to withstand root rot infections. These practices include understanding the Aphanomyces life cycle, identifying the risks for root rot infection, confirming Aphanomyces oospore load through soil and tissue tests, tracking weather data and previous crop history, and avoiding building Aphanomyces spore loads by managing crop rotation.
Varieties
There are currently no registered Aphanomyces-resistant pea or lentil varieties. See Breeding and Research to understand what has been done and future research directions. Research and investment in varietal development and genetic resistance are ongoing across the western provinces and the United States (U.S.) to release pea and lentil varieties with resistance to Aphanomyces and the root rot complex. With partial resistance, the disease severity can be reduced but not eliminated.
Seed Treatments
Some seed treatments have been labelled as suppressing Aphanomyces euteiches; however, efficacy is tied to several caveats. Seed treatments will not have activity on Aphanomyces infections 28–35 days following seeding, and foliar fungicides have zero activity on root rot diseases.
Rotation
Rotation management, which involves removing peas and lentils from the rotation for six or more years, is the only real management option available to growers. Growers and agronomists should ask several questions to determine the risk level for future Aphanomyces infections and how long they should avoid growing peas or lentils in a particular field.
Visit Agronomy to learn more
Soil Amendment Research
Ongoing research, led by Dr. Syama Chatterton and Dr. Michelle Hubbard, is investigating different soil amendments and the use of natural products to reduce Aphanomyces oospore load in the soil. One such project is investigating whether liming soils will suppress Aphanomyces root rot and whether it is economically and physically feasible for growers. It has also determined whether soil amendments could reduce Aphanomyces in patchy areas.
Calcium is thought to prevent zoospore production from oospores, as soils with more free calcium seem to have greater Aphanomyces suppression and subsequent disease reduction. Preliminary results have indicated that surface applications of lime did not change the calcium concentration of the soil, and incorporation of high amounts of lime would likely be necessary.
Hydrated lime has been proven to kill Aphanomyces in sugar beet but has not yet been demonstrated to kill pulses.
Other applications, such as MustGrow, seed treatments, nitrogen and phosphorous fertilizers, and lime and calcium products, are also being tested with varying results. Please see the Research and Resources pages for more information on the ongoing root rot research.