Botrytis (Grey Mould)
Botrytis cinerea
Fuzzy grey mould on soft fruit and dying flowers. Thrives in humid still conditions. Major problem on strawberries and tomatoes.
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Identify from a photoBackground
Botrytis cinerea is a broad-host-range necrotrophic fungus. It colonises dying tissue, senescent flower petals, damaged leaves, split fruit, then moves into healthy tissue. In humid weather it sporulates prolifically, producing the characteristic grey fuzzy mould on affected surfaces.
How to identify
- Soft watery rot of fruit, petals or stems
- Distinctive fuzzy grey mould coating the rotted area
- Sometimes ghost spots on tomato fruit (small white halos) where spores germinated but did not establish
- Dark lesions on stems, especially after wounds
Life cycle
Spores wind-borne or rain-splashed. Germinate on wet surfaces in 4-8 hours. New spores on rotted tissue in 3-5 days. Overwinters as sclerotia in crop debris.
Weather triggers
- Temperature: 10-25°C
- Humidity: >85%
- Rainfall trigger: >2mm
- High humidity and extended leaf wetness. Still cool humid weather is peak risk.
Peak season (southern hemisphere)
Red = active season · Dark red outlined = this month
Affected vegetables & crops
Click any crop to see current prices and growing info.
Climate zones at risk
Organic & low-impact control
- Remove affected fruit and dying flowers promptly
- Improve airflow. Prune and space plants
- Avoid overhead watering late in the day
- Copper-based protectants at first sign
Chemical control
- Several systemic fungicides (boscalid, fenhexamid) registered for commercial use
- Home gardeners should focus on sanitation and airflow
Always read product labels. Registrations change.
Prevention
- Stake and prune for open airflow
- Clean up dying flowers and fallen fruit
- Mulch to prevent soil splash
Companion planting
No direct companion effect.
Biosecurity
Worldwide distribution, no quarantine issue.
Know when Botrytis (Grey Mould) is actually about
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