Anthracnose
Dark, sunken spots on fruit, leaves and stems in warm, wet weather — rotting the produce and dying back the shoots.
- Pathogen
- Fungus (Colletotrichum)
- Spreads by
- Rain-splash; seed & debris
- Favoured by
- Warm, humid, rainy weather
- Main risk
- Rotted fruit; shoot die-back
Overview
Anthracnose is a common fungal disease (mostly Colletotrichum species) of warm, humid, rainy weather. It produces dark brown to black, often sunken spots on leaves, stems, flowers and — most damagingly — the fruit, and the centre of a spot frequently bears tiny pink or salmon-coloured masses of spores in moist conditions.
On chilli it causes the fruit-rot and "die-back" complex (fruit rots with sunken spots, and shoots die back from the tip); on mango, grapes, guava, pomegranate and papaya it spots and rots the fruit, often appearing after harvest as the fruit ripens; and on sorghum it causes leaf and stalk anthracnose. It spreads in rain-splash and is favoured by warm, wet weather, so it flares in the monsoon and can carry over on infected plant debris and seed.
How to identify it
- Dark brown to black, often sunken spots on the fruit that enlarge and rot it, sometimes in concentric rings.
- Tiny pink or salmon-coloured masses of spores in the centre of the spots in moist weather — a good diagnostic.
- Dark spots and blights on leaves and stems, and "die-back" of shoots from the tip downward (notably in chilli).
- Fruit rot that often shows up after harvest as the fruit ripens in storage or transit.
What causes it and when
- Colletotrichum fungi, spread mainly by rain-splashed spores and carried on infected seed and crop debris.
- Favoured by warm, humid, rainy weather — it flares in the monsoon and in dense, wet canopies.
- Infection can be latent — the fungus enters the young fruit and stays quiet until the fruit ripens, then rots it.
- Carried over on infected plant debris, mummified fruit and seed from season to season.
Cultural & organic control
- Use clean, disease-free (and, where relevant, treated) seed and planting material, and grow resistant/tolerant varieties.
- Remove and destroy infected fruit, shoots, mummified fruit and crop debris that carry the fungus over; prune for an open, airy canopy.
- Improve drainage and airflow and avoid overhead irrigation so the canopy and fruit dry quickly.
- Follow crop rotation, and treat seed with a recommended bio-agent (e.g. Trichoderma) where advised.
Chemical control
- Spray protectively before and during warm, wet weather, and at flowering–fruit set on fruit crops, before the fungus infects the fruit.
- CIB&RC-registered fungicides for anthracnose on the crop — copper-based and other recommended fungicides — are used and rotated to avoid resistance.
- Cover the fruit and foliage well, and observe the pre-harvest interval, especially on frequently-picked crops like chilli.
- Confirm the current recommendation for your crop and area with your local KVK.
Prevent it coming back
- Start with clean seed/planting material and resistant varieties, and rotate crops.
- Sanitation is key — destroy infected fruit, mummies and debris so the fungus cannot carry over.
- Manage the canopy and irrigation for quick drying, and spray protectively ahead of monsoon/wet spells.
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 chilli/fruit has dark sunken spots and is rotting, with pinkish centres. What is it?
That is anthracnose. It causes dark, sunken spots on the fruit that rot it, often with tiny pink or salmon spore masses in the centre in moist weather, and on chilli it also dies back the shoots. It thrives in warm, wet weather and spreads by rain-splash. Remove infected fruit and debris, improve airflow, and spray protectively before wet weather.
Why does the fruit rot only after harvest sometimes?
Because anthracnose infection can be latent — the fungus enters the young fruit in the field and stays quiet until the fruit ripens, then develops into a rot in storage or transit. That is why protecting the fruit at flowering and fruit set (before infection), plus sanitation, matters more than treating visible rot after it appears.
How do I stop anthracnose carrying over each season?
Sanitation and clean material. The fungus survives on infected seed, mummified fruit, fallen infected fruit and crop debris, so use clean/treated seed and resistant varieties, and remove and destroy all infected fruit, mummies and debris after harvest. Combine this with crop rotation, an open airy canopy, and protective sprays ahead of warm wet weather.
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.