Plant Health Initiative

Northern Stem Canker - Risk Assessment

Stem canker Click on image to view a larger version Photo credit: Thomas Chase, SDSU

The risk of Northern stem canker is generally low for most farmers. Disease outbreaks are difficult to predict because they are highly dependent on environmental conditions.

Factors that favor the development of stem canker are

• Field history: fields that have experienced stem canker are at high risk for outbreaks when planted again to soybean because of the pathogen's ability to survive for long periods in soil and residue.
• Tillage: infected soybean residue left in no-till or conservation tillage fields supports the survival of the stem canker fungus.
• Rainy periods around V3 growth stage when the fungus infects the plant
• Warm temperatures
• High canopy humidity
• Poor seed health: levels of seed infection by D. phaseolorum var. caulivora can range from 10 to 20%. Researchers in Minnesota report that outbreaks are often are field- and seedlot-specific, which may be the result of seed contamination.
• Susceptible soybean variety