| CAUSED BY |
- Pathogens (various fungal and fungus-like organisms) associated with root rot often appear as a complex, where more than one pathogen is present, making identification of the primary causal agent difficult.
- These diseases are caused by several fungi including Pythium, Rhizoctonia, Botrytis, and Fusarium species.
- These soil-borne fungi are seed or soil-borne and can infect the plant at any stage between germination and maturity, and any part of the root system up to a short distance above the soil surface.
- These fungi are common in the soil, and infection is more likely if the soil around the seed is excessively wet. Warm and moist conditions generally favour these diseases, but cold and wet is also detrimental because the cool temperatures slow plant development and add additional stress.
- Other factors, including abiotic conditions such as flooding and soil oxygen depletion can result in root cell death.
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| SYMPTOMS |
- Poor emergence, stunting, yellowing of leaf tissues, a less well developed root system, decay, and brown discolouration of roots.
- Typically occur in patches and may expand if conditions are favourable for the pathogens over several growing seasons. Symptoms are often associated with areas of flooding or waterlogging.
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| PREVENTION AND CONTROL |
- As prevention measure, seed treatments offer protection to the developing seedling, especially under cool, wet conditions when emergence may be delayed.
- A four to five-year rotation out of pea or other susceptible hosts (alfalfa and clovers).
- Use seed with high vigour, practice good soil fertility, liming of acid soils and ripping to reduce soil compaction.
- Avoid herbicides such as: MCPA, MCPB or a mix of MCPA and MCPB – these herbicides cause plant stress and make root rot more severe.
- For recommendations in managing root rot, see the link below.
- Once root rot has set in, there is nothing that can be done.
- Understanding the disease, identifying the risks for root rot infection, and thorough planning for prevention are the only current options.
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| IMPACT |
- Yield loss, stunting of plants.
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| RESOURCES |
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