The soybean crop is much of Ontario has seen some pretty major extremes this year: drought, flooding, cold, heat, insects; the list goes on and on. While you may have seen issues in the fields relating to these, you may also seem some symptoms of damage that are hard to identify and you can’t quite put your finger on what is causing issues.
Often times, those stunted, yellow areas can be caused by Soybean Cyst Nematode.
Soybean Cyst Nematode (SCN) is the number one pest of soybeans in Ontario. Yield losses from SCN can reach 40% or more, especially in drier years.
Here’s what you need to know about SCN:
- SCN is a microscopic parasite that enter and feed inside roots of soybeans and edible beans
- Damage can be highly variable, but can include stunting, yellowing, and crop death
- Often confused with nutrient deficiencies, herbicide injury, etc.
- Can often lead to increase in diseases like Sudden Death Syndrome in soybeans
- Small whitish cysts are visible on roots (don’t confuse with nodules)
- Dig up and carefully wash soil away to confirm infection
- Soil sample analysis is used to identify the level of infestation
- Test results show whether you have SCN, and at what population
- High populations correlate to more damage in the field, and whether you are at risk of damage even in SCN-resistant soybean varieties
- Crucial to rotate to non-host crops like corn, cereals, alfalfa, etc.
- Rotate sources of SCN resistance in soybean varieties (ie. from PI 88788 to Peking or Hartwig)
SCN is a major pest in soybeans, but can be managed with the proper techniques!