Most common under good soil moisture conditions, Aphanomyces root rot is a soil-borne disease that continues to affect pea and lentil crops in Western Canada. It is very difficult to identify and isolate using conventional methods and often requires a DNA test to confirm.
Pathogen numbers tend to increase in relation to the number of times peas or lentils have been planted in a field. So continuously growing the same crops in the same field over a 20-year period can increase soil pathogen levels under the right conditions.
According to Dr. Sabine Banniza, Professor of Plant Pathology at the University of Saskatchewan Crop Development Centre, the spores produced by this fungus are very resilient
“So, a year of drought will not make a big dent in the number of viable spores in the soil of an infested field,” she says. “They will sit there and wait out the drought, and when there is some moisture in the soil, and it doesn’t take much, and another pea or lentil crop is planted, they will revive and infect.
Right now, there are no in-crop management options for the disease so the best way to prevent outbreaks is to pay close attention to previous crops and the growing environments and by planning crop rotations carefully.
The Saskatchewan Pulse Growers offer pea and lentil growers these four practices to manage or prevent Aphanomyces when planning.
1. Record
It is important to record the state of your crops from year to year. Pay attention to signs of disease, such as stunted growth or yellowing in low-lying or damp areas.
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Know what year you last planted peas or lentils and what the environment was like at that time.
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Years of above-average moisture tend to increase outbreaks and spread of the disease. The pathogen’s spores need moisture to move through the soil, but they can lie dormant, waiting for ideal conditions for years.
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Check and test your roots and look for signs of root rot in your fields.