Pythium stalk rot
Area of impact: Stalk
Description: Infection is limited to individual plants in small areas and to the first internode above the ground. The infection site will look brown watery and soft. Stalks may be twisted and tissue may completely rot but inner tissue will remain intact and the plant may stay green for weeks.
Pathogen involved: Pythium aphanidermatum (a fungus-like pathogen)
Timing/Conditions: Usually occurs after pollination during very hot and wet weather.
Contributing factors: Poor soil drainage and high humidity increase disease risk. Overwinters in soil.
Management practices: Improve soil drainage