White Mold: Urgent! How to Save Your Plant
White mold (Sclerotinia sclerotiorum) is a devastating fungal disease affecting over 400 plant species worldwide. The fungus produces black, seed-like structures (sclerotia) that can survive in soil for 5 or more years. The disease is favored by cool, moist weather (50-68°F/10-20°C), especially during flowering.
Fast
21 days
🔍 Symptoms
Main Symptoms
- ! Sudden wilting and yellowing of leaves
- ! Fluffy white mold growth on stems and leaves
- ! Water-soaked lesions expanding irregularly
- ! Soft, watery rot near soil level
- ! Black sclerotia (0.5-1cm) in white fungal mass
- ! Grayish-green appearance before wilting
- ! Infected stem sections become brittle and tan-colored
Visual Signs
❓ Possible Causes
- → Fungus Sclerotinia sclerotiorum surviving in soil via sclerotia
- → Prolonged cool, moist conditions (50-68°F/10-20°C)
- → High humidity during flowering period
- → Poor air circulation from dense planting
- → Wind-borne spores from germinated sclerotia
- → Direct contact with contaminated soil
- → Fungus survival on plant debris for 5+ years
💊 Treatment
Quick Fixes
~11 days
Immediate removal
Remove and completely destroy all infected plants. Burn or bag and dispose in trash.
Apply fungicide
Apply systemic fungicide (SDHI or DMI) to neighboring healthy plants preventively.
Reduce moisture
Stop all overhead watering. Use drip only. Improve ventilation/drainage.
Isolate area
Create buffer zone by removing plants within 20-inch radius of infection.
Intensive monitoring
Inspect remaining plants 2x daily for 14 days.
Materials needed:
Organic Treatment
~21 days
Remove infected plants
Carefully remove entire plant without spreading sclerotia. Burn or bury deeply (24+ inches). Do not compost.
Apply biocontrol
Apply Coniothyrium minitans to soil per instructions. This fungus parasitizes Sclerotinia sclerotia.
Improve circulation
Thin adjacent plants to improve airflow. Space plants 12-18 inches apart.
Adjust irrigation
Switch to drip irrigation. Water early morning. Avoid wetting foliage.
Soil solarization
If possible, cover soil with clear plastic for 4-6 weeks in summer (kills sclerotia).
Monitoring
Inspect plants daily for 3 weeks. Remove any new infection immediately.
Materials needed:
Expert Treatment
~32 days
Assessment and removal
Identify all symptomatic plants. Remove with 12-inch safety margin. Document infection locations.
Soil analysis
Collect soil samples from affected areas. Test sclerotia population (<1 sclerotia/100g soil = low risk).
Biocontrol + chemical
Apply Coniothyrium minitans to soil (10-20g/m²). Apply preventive foliar fungicide (azoxystrobin or boscalid) to healthy plants.
Environmental optimization
Reduce planting density to ≥16-inch spacing. Install subsurface drip irrigation. Maintain pH 6.0-6.5.
Rotation program
Plan 3-year rotation: Years 1-2 cereals/grasses, Year 3 return of susceptible crops.
Professional solarization
In affected beds, solarize for 6-8 weeks (June-August). Soil temperature must reach >113°F (45°C).
Monitoring and prevention
Implement weekly monitoring system. Apply preventive fungicides at early flowering. Maintain infection records.
Step by Step
- 1
Remove and destroy all infected plants immediately (burn or bury deep)
- 2
Do not compost infected material - destroy completely
- 3
Improve air circulation by reducing planting density
- 4
Apply preventive fungicide to neighboring healthy plants
- 5
Reduce irrigation and humidity around plants
- 6
Apply biocontrol agent Coniothyrium minitans to soil
- 7
Monitor neighboring plants daily for 2-3 weeks
🧪 Solutions
🌱 Natural Solutions
- ✓ Apply Coniothyrium minitans (biocontrol agent) reducing sclerotia by 95%
- ✓ Use well-composted material at 148-158°F (65-70°C) for 21+ days
- ✓ Apply potassium bicarbonate or sulfur as preventive
- ✓ Soil solarization in affected areas during summer
- ✓ Plant resistant species like ornamental grasses
💉 Chemical Solutions
- ✓ Methyl benzimidazole carbamate fungicides
- ✓ Succinate dehydrogenase inhibitors (SDHI)
- ✓ Demethylation inhibitors (DMI/azoles)
- ✓ Apply preventively at early flowering
- ✓ Repeat applications per label instructions
🛡️ Prevention
- ✓ Plant with proper spacing to promote air circulation
- ✓ Avoid excessive irrigation during and after flowering
- ✓ Use drip irrigation instead of overhead sprinklers
- ✓ Remove and destroy infected plants immediately
- ✓ Implement crop rotation with 2-3 years of non-host crops (cereals, corn)
- ✓ Water early in day so foliage dries before nightfall
- ✓ Clean up all crop debris after harvest
- ✓ Avoid planting susceptible species in areas with disease history
