🦠 Colletotrichum kahawae | The Coffee Lexicon

Coffee farming faces many challenges, but few diseases have earned the reputation of Colletotrichum kahawae.

This fungal pathogen is responsible for Coffee Berry Disease (CBD), one of the most destructive diseases affecting Arabica coffee production in parts of Africa. 🌍☕

For coffee producers in vulnerable regions, understanding this fungus is essential for protecting harvests, maintaining quality, and preserving livelihoods.

📖 What is Colletotrichum kahawae?

Colletotrichum kahawae is a fungus that infects developing coffee cherries, causing a disease commonly known as Coffee Berry Disease. Unlike many coffee pathogens that attack leaves or roots, this fungus specifically targets the fruit itself. 🍒

The disease was first identified in Kenya during the 1920s and quickly became one of the greatest threats to coffee production across eastern and central Africa.

Learn more in our related article: Deep Dive | Coffee Berry Disease.

🔬 How Does the Fungus Infect Coffee?

The fungus spreads through microscopic spores that thrive in cool, wet conditions. 🌧️ Once spores land on young coffee cherries, they germinate and penetrate the fruit's outer skin.

After infection occurs, dark lesions begin to develop and rapidly expand across the cherry surface. Eventually, the infected berries become black, shriveled, and unusable.

The infection cycle often follows this pattern:

• 🌧️ Rain splashes fungal spores onto nearby cherries.
• 🍒 Spores germinate on immature fruit.
• 🦠 The fungus penetrates the berry tissue.
• ⚫ Dark lesions form and spread rapidly.
• 📉 The berry dries out or falls prematurely.
• 🔁 New spores spread to neighboring trees.

🌍 Where is Coffee Berry Disease Found?

Coffee Berry Disease is primarily found in higher-altitude coffee-growing regions of Africa where cool temperatures and regular rainfall create ideal conditions for fungal growth.

Major affected regions include:

• 🇰🇪 Kenya
• 🇺🇬 Uganda
• 🇷🇼 Rwanda
• 🇧🇮 Burundi
• 🇪🇹 Ethiopia
• 🇹🇿 Tanzania
• 🇨🇲 Cameroon

Fortunately, the disease has not established itself in major coffee-producing countries in South America such as Brazil and Colombia, largely due to geographic isolation and strict agricultural controls. 🚢🛃

💥 Why is it So Dangerous?

Unlike some coffee diseases that gradually weaken a plant over time, Colletotrichum kahawae directly attacks the crop that farmers depend on for income.

Under severe outbreak conditions, farmers may lose:

• 📉 20–30% of annual production during moderate outbreaks.
• ⚠️ More than 80% of the harvest during severe epidemics.
• 💰 Significant export revenue for producing countries.

Because the fungus attacks cherries before harvest, entire seasons of work can be lost within weeks.

🛡️ How Farmers Fight the Disease

Coffee producers use several strategies to reduce the impact of Coffee Berry Disease:

• 🌱 Planting resistant Arabica varieties.
• ✂️ Pruning trees to improve airflow.
• 🌳 Managing shade levels to reduce humidity.
• 🧹 Removing infected berries from the field.
• 🧪 Applying fungicides when necessary.
• 📊 Monitoring weather conditions and outbreak risks.

Researchers continue developing more resistant coffee cultivars to reduce dependence on chemical controls.

Explore more: Deep Dive | How Farmers Monitor and Manage Outbreaks

🧬 Is it Related to Coffee Leaf Rust?

No. Although both are fungal diseases, they are caused by completely different organisms and attack different parts of the coffee plant.

Related reading: Deep Dive | Coffee Leaf Rust

☕ Why Coffee Drinkers Should Care

Diseases like Colletotrichum kahawae influence far more than farm yields. They can affect:

• 💲 Global coffee prices.
• 📦 Supply chain stability.
• 🌱 Sustainability efforts.
• 👨🌾 Farmer livelihoods.
• ☕ Availability of specialty African coffees.

Every cup of coffee represents years of work and countless environmental risks. Understanding these threats gives consumers a deeper appreciation for the resilience of coffee farmers around the world.

📚 Lexicon Summary

Colletotrichum kahawae is the fungal pathogen responsible for Coffee Berry Disease (CBD), a major threat to Arabica coffee production in Africa. The fungus infects developing coffee cherries, reducing yields and damaging coffee quality. Through resistant varieties, improved farm management, and ongoing research, the coffee industry continues working to reduce its impact and protect future harvests. ☕🌍🦠

🔗 Continue exploring the lexicon: The Coffee Lexicon Hub