Effective Strategies for Managing Anthracnose in Chilli Crops

Chilli anthracnose, caused by fungus Colletotrichum capsici, is a significant threat to chilli crops worldwide. This devastating disease affects both plant foliage and fruit, leading to yield losses and reduced crop quality. Understanding the causes, symptoms and effective management strategies is crucial for the farmers seeking to protect their chilli harvests from the damaging impacts of anthracnose. In this article, we will explore the main features of this fungal infection and how to manage it.  

Mode of Spread and Survival

• Temperature of about 28°C, Relative Humidity 92- 95% and rainfall during the ripening stage of the fruit favors disease development.
• The fungus is seed borne externally and secondary spread occurs through airborne conidia.
• Survival takes place on dead twigs under dry conditions and in the field within plant debris.

Symptoms

The disease manifests in two phases: dieback and ripe fruit rot. 

Dieback Phase

• Primary symptoms involve the necrosis of the tender twigs, starting from the tip and progressing downward.
• As the disease progresses, the twigs may become straw-colored.
• Numerous black dots (fungus acervuli) can be seen scattered across the necrotic spots.
• Severe attacks can lead to the withering of the entire plant.
• The fungus can also affect the fruit stalk and stem.

Ripe Fruit Rot Phase

• Small, black, circular spots appear on the fruit skin.
• These sunken spots with black margins develop a pinkish mass of fungal spores.
• As the disease progresses, concentric markings with dark fructifications (fungus acervuli) form, causing premature fruit drop and significant yield loss.
• When diseased fruits are cut open, the lower skin surfaces are covered with tiny elevated black stromatic masses of the fungus.
• In advanced stages, the seeds are covered by a mat of fungal hyphae, resulting in a rusty color.

Preventive Measures

• Regularly inspect seeds or orchards for signs of the disease.
• Ensure proper drainage in the fields.
• Implement an extended crop rotation plan with non-host crops (3-4 years or more).
• Use disease free chilli seeds for planting.
• Remove infected fruits and infected plant debris from the field as they serve as the sources of inoculum.
• Harvest crops early to minimize the severity of symptoms.

Management of Chilli Anthracnose

A combination of biological and chemical control measures is often required to effectively manage anthracnose infections in chilli crops. Fungicides that can be used to control are mentioned in the table below: