Diseases
Pythium-Associated Root Rot
Pythium-associated root disease is favored by vulnerable roots and water-mediated spread in many production systems. Brown roots or wilt alone are not enough to establish the cause.
What to look for
- Loss of healthy fine-root structure
- Root discoloration and tissue sloughing in advanced cases
- Wilt or reduced vigor despite adequate bulk moisture
- Patterns associated with shared irrigation or chronically wet zones
Important look-alikes
- Low-oxygen root injury
- Fusarium-associated disease
- High EC or fertilizer injury
- Heat-damaged roots
How to confirm
- Inspect root tissue and root-zone conditions
- Compare affected and unaffected irrigation zones
- Use laboratory diagnosis for important outbreaks
- Review water movement and sanitation history
Management principles
- Reduce conditions that chronically deprive roots of oxygen
- Prevent contaminated water from recirculating without appropriate treatment
- Remove severely affected plants when they become inoculum reservoirs
- Clean and disinfect appropriate equipment between crops
Prevention
- Maintain good drainage and irrigation control
- Use clean propagation material and media
- Keep floors and drains clean
- Monitor roots before canopy symptoms become severe
Visual study guide
- Healthy versus declining root plate
- Water-mediated spread diagram
- Pythium versus abiotic root stress comparison
- Root inspection workflow