Botrytis grey mould
A soft rot coated in fuzzy grey-brown mould on flowers, pods, fruit and grape bunches — a cool, humid, wet-weather fungus of dense, wet canopies.
- Pathogen
- Fungus (Botrytis cinerea)
- Spreads by
- Air-borne spores; debris; on injured tissue
- Favoured by
- Cool, humid, wet weather; dense wet canopy
- Main risk
- Rotted flowers, pods & bunches; produce loss
Overview
Botrytis grey mould (Botrytis cinerea) is a widespread fungus that causes a soft, watery rot covered in a characteristic fuzzy, grey to grey-brown mould. It attacks flowers, pods, fruit, leaves and stems, and is especially damaging on grape bunches (bunch rot) and on chickpea flowers and pods (grey mould of chickpea), among many other crops. The affected tissue rots and is soon coated in the tell-tale grey fuzz of the fungus’s spores.
It thrives in cool, humid, wet, cloudy weather and on dense, poorly-ventilated canopies that stay wet, and it readily colonises injured, ageing or dead tissue (spent flowers, wounds, cracked fruit) before spreading into healthy tissue. In chickpea it rots flowers and young pods, causing serious pod loss in a wet spell; in grapes it rots the bunches before and after harvest. It carries over on debris and spreads by air-borne spores. Management combines opening up the canopy, sanitation and drainage, avoiding injury, and protective fungicides in wet, high-risk periods.
How to identify it
- A soft, watery rot of flowers, pods, fruit or bunches soon coated in fuzzy, grey to grey-brown mould.
- In chickpea: rotting of flowers and young pods with grey mould in a cool, wet spell, causing pod loss.
- In grapes: soft rotting of the bunch (bunch rot) with grey fuzz, before and after harvest.
- Worst in dense, wet, poorly-ventilated canopies and on injured, ageing or dead tissue.
What causes it and when
- The fungus Botrytis cinerea, spread by air-borne spores and carried over on crop debris.
- Favoured by cool, humid, wet, cloudy weather and dense, poorly-ventilated canopies that stay wet.
- Colonises injured, ageing or dead tissue (spent flowers, wounds, cracked fruit) first, then spreads into healthy tissue.
- Worst in a wet spell at flowering/podding (chickpea) or as bunches ripen (grapes).
Cultural & organic control
- Open up the canopy — spacing, pruning, training and good drainage — so it dries and is well-ventilated.
- Avoid excess nitrogen and dense, lush growth, and remove spent flowers, debris and mummified/rotted fruit.
- Avoid injury to fruit and pods, and manage cracking (grapes), which lets the fungus in.
- Harvest promptly and handle produce gently, and store cool and dry.
Chemical control
- Apply protective fungicides in cool, wet, high-risk periods — CIB&RC-registered Botrytis fungicides, rotated to avoid resistance.
- Time sprays to flowering/podding (chickpea) or the pre-harvest bunch period (grapes) when infection occurs.
- Cover the vulnerable tissue and observe the pre-harvest interval, especially on grapes for the table/market.
- Confirm the current product, dose and schedule for your crop with your local KVK.
Prevent it coming back
- Make an open, well-drained, well-ventilated canopy and sanitation the routine, and avoid excess nitrogen.
- Remove debris, spent flowers and rotted/mummified fruit, and avoid injury and cracking.
- Plan protective sprays for cool, wet spells at the vulnerable stage rather than reacting after the rot spreads.
Crops most at risk
Where this problem is called out in our crop guides — open a crop for the full package of practices.
Frequently asked questions
My chickpea flowers/pods (or grape bunches) are rotting with a fuzzy grey mould in wet weather. What is it?
That soft, watery rot coated in fuzzy grey to grey-brown mould is Botrytis grey mould (Botrytis cinerea). It thrives in cool, humid, wet weather and on dense, wet canopies, rotting flowers and pods in chickpea and bunches in grapes. Open up the canopy for airflow and drying, remove debris and spent flowers, avoid injury, and apply protective fungicides during cool, wet, high-risk spells at flowering/podding or the pre-harvest bunch stage.
Why does Botrytis attack spent flowers and injured tissue first?
Because Botrytis is a great coloniser of weak, ageing or dead tissue: spent flowers, wounds and cracked or over-ripe fruit give it an easy food base to establish on, from which it then spreads into adjacent healthy tissue. That is why removing spent flowers and rotted fruit, avoiding injury and cracking, and keeping the canopy open and dry are so effective — they deny the fungus the damp, dead tissue it needs to get started, reducing how much healthy produce it can go on to rot.
How do I reduce grey mould without relying only on fungicide?
Focus on the canopy and moisture, since Botrytis needs cool, wet, poorly-ventilated conditions. Open up the canopy with spacing, pruning and training, ensure good drainage, and avoid excess nitrogen and dense lush growth so the foliage and fruit dry quickly. Remove spent flowers, debris and rotted or mummified fruit, avoid injury and (in grapes) cracking, and harvest and handle gently. These cultural steps cut the disease sharply, so any protective fungicide in a wet spell works much better.
Symptoms and control measures follow ICAR, KVK and state agricultural-university package-of-practices; any named chemical is a registered use. Always read the product label and confirm the dose for your crop and zone. editorial policy.