Round-leaf Calathea with Fusarium Wilt: Prevention & Cure
Calathea orbifolia
Fusarium wilt is a serious fungal disease caused by the soil-borne fungus Fusarium oxysporum. The fungus invades roots and blocks the water-conducting vessels (xylem) of the plant, causing progressive wilting and eventual death. Host-specific forms of the pathogen exist that attack different plant species.
ð Symptoms
- âĒ Wilting during the hottest part of the day with recovery at night (early stage)
- âĒ Asymmetrical yellowing of leaves (one side of plant or leaflets)
- âĒ Progressive upward wilting from the stem base
- âĒ Dark red to brown discoloration of vascular tissues
- âĒ Stunted growth and dwarfism
- âĒ Pale green to golden yellow foliage
- âĒ Progressive death of leaves from bottom to top
â Possible Causes
- â Infection by soil-borne fungus Fusarium oxysporum
- â Entry through roots, especially wounds
- â Soil temperature above 75°F (24°C) favors development
- â Acidic soil and excess nitrogen increase susceptibility
- â Contaminated tools and infected soil
- â Contaminated transplants and seeds
ð Treatment
Quick Fixes
Remove Plant
Immediately remove entire infected plant with roots. Dispose in sealed trash (DO NOT compost).
Disinfect Area
Spray area with diluted bleach solution (1:10). Allow to dry.
Apply Biofungicide
If available, immediately apply Mycostop or Trichoderma to affected soil.
Isolate Area
DO NOT plant anything in same area for at least 6 months. Fusarium remains in soil.
Organic Treatment
Immediate Removal
Completely remove infected plant including all roots. Do not compost - burn or dispose in sealed trash.
Tool Disinfection
Clean all tools with 10% bleach solution for 5 minutes. Allow to dry completely in sun.
Soil Solarization
Cover affected area with clear plastic for 4-6 weeks in summer. Heat eliminates pathogens.
pH Correction
Test soil pH. If acidic, add lime to raise pH to 7.0-7.2. Fusarium prefers acidic soils.
Biological Inoculation
Add well-cured compost rich in Trichoderma or apply biological product (Mycostop). Wait 2 weeks before replanting.
Replant with Resistant Varieties
Use ONLY Fusarium-resistant varieties. Check certification. Maintain good drainage.
ðĄïļ Prevention
- â Use Fusarium-resistant varieties (most effective method)
- â Crop rotation for 3-5 years away from susceptible plants
- â Raise soil pH to 7 in acidic soils
- â Avoid excessive nitrogen in fertilization
- â Use certified disease-free seeds and transplants
- â Clean soil and debris from all tools
- â Improve soil drainage
- â Avoid root injuries during transplanting
- â Soil solarization in infected areas
ðą Care Guide: Round-leaf Calathea
ð§ How to Water
Keep the substrate consistently moist but not waterlogged. Water approximately every 7 days in summer and every 10-14 days in winter. Use filtered or water left to sit for 24-48 hours to avoid mineral damage.
âïļ Lighting
Place in an area with medium to high indirect light, near a window but protected from direct sun. Avoid direct sunlight at all costs as it will burn the leaves.
ðŠī Ideal Soil
Requires acidic, well-draining substrate rich in organic matter. Porous composition helps prevent root rot while maintaining necessary moisture.