Outer and Inner Stem Symptoms of Charcoal Rot
Plants dying due to Charcoal Rot infection.
Infected soybean plant at harvest, showing stem symptoms and reduced yield (low number of pods and seeds)
May cause moderate to significant yield loss, depending on disease severity and environmental conditions
— Seedlings to early reproductive plants may die or be severely stunted (see image below)
— Entire fields may show disease symptoms
An integrated management approach is required to reduce microslerotia levels in the soil and stresses to the crop
Rotation can help ease but not eliminate problem
Variety Selection - No highly effective sources of resistance are currently available in commercial soybean varieties. However, Pioneer® brand soybean varieties differ in tolerance to charcoal rot drought complex
Irrigation, where available, helps reduce drought stress, (especially important during reproductive stages R1 to R7)
Scouting – Scout to determine tolerance of varieties to charcoal rot and note for next year’s variety decisions
Seeding and Fertility – Avoid excessive seeding rates and maintain adequate soil fertility levels (especially potassium) to reduce disease incidence and severity
Chemical / Biological control measures are currently not available to help manage charcoal rot
Reduced Tillage systems may help conserve moisture but also increase disease inoculum in crop residue
Weed Management – Controlling weeds reduces alternate hosts and competition for available soil moisture
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Credits: Images and review by Larry Osborne and Jim Boersma, DuPont Pioneer Field Agronomist and DuPont Pioneer Product Agronomist, respectively. Review by Les Kuhlman, DuPont Pioneer Research Scientist
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