Disease Cycle:

Physoderma maydis, causes both foliar and the stalk rot phase. Sporangia overwinter in residue or can survive without a host in soil 2-7 years. Spores are spread through wind or rain and infect inside the whorl of corn plants during V3-V9. Infection requires free water, light & warm temps. Reinfection can occur after 40-50 days, this is often when node infection appears. Physoderma stalk rot can occur in fields without the presence of foliar symptoms

Favorable Conditions:

Favorable conditions are long periods of saturation, heavy rainfall events and Temps of 72.-90., 48-72 hrs. of continuous free water causes high infection rates

Management/Treatment:

• Hybrid selection remains the most valuable tool to avoid problems
  • Avoid placing susceptible hybrids in soils known to have a history
• Rotation to a non host crop will help to reduce inoculum
• Tillage is not effective and may actually increase survival rates in the soil
• Many fungicides are labeled to control Physoderma but often times remain ineffective due to timing and poor coverage deep within a corn plants whorl
  • An early preventive V3-V5 application can help to reduce or prevent infection rates

Physoderma Stalk Rot