Anthracnose is a common fungal disease that affects pepper plants, primarily impacting the fruit but also appearing on leaves and stems. It can lead to substantial reductions in yield and affect marketability. This article outlines how to identify anthracnose and strategies for its control and prevention.
Recognizing Anthracnose
Anthracnose typically appears on pepper fruit as small, sunken lesions that can enlarge and develop concentric rings. A characteristic sign is the presence of salmon-pink spore masses emerging from these lesions, especially in humid conditions. On ripe fruit, lesions may cause discoloration, while on green fruit, symptoms often appear as the fruit matures. The disease can also affect leaves, manifesting as irregular, small, dark spots that turn brown to gray with dark edges. Stem infections can occur, though fruit damage is usually most significant.
Conditions Favoring Anthracnose
Anthracnose is caused by Colletotrichum fungi, which thrive in warm, humid environments, with 80°F (27°C) optimal for development. Prolonged leaf wetness, from rain or overhead irrigation, creates favorable conditions for spore germination and infection. The disease spreads through splashing water, dispersing fungal spores from infected plants or contaminated soil. The pathogen survives between seasons in infected plant debris, on weed hosts, or within seeds, allowing it to persist.
Controlling the Disease
Managing an existing anthracnose infection requires prompt action to limit its spread by removing and destroying all infected plant parts, including fruit, leaves, and stems. Dispose of this diseased material away from healthy plants, avoiding composting that could spread the pathogen. Regularly cleaning gardening tools with a disinfectant prevents spore transfer. Improving air circulation around pepper plants through strategic pruning reduces leaf wetness and humidity. For severe outbreaks, certain fungicides labeled for anthracnose on peppers can be considered as a last resort, following product label instructions carefully.
Protecting Your Plants
Preventing anthracnose outbreaks begins with foundational gardening practices, starting with disease-free seeds or seedlings to avoid introducing the pathogen into your garden. Practicing crop rotation, specifically avoiding planting peppers or other solanaceous crops in the same area for at least two to three years, helps to reduce pathogen buildup in the soil. Proper plant spacing allows for better air circulation and quicker drying of foliage, reducing the humid conditions that favor fungal development. Watering techniques that minimize leaf wetness, such as drip irrigation or watering at the base of the plant, are also beneficial. Managing plant debris by promptly removing and incorporating it into the soil after harvest can help reduce overwintering sites for the fungus, and selecting pepper varieties known to have some resistance provides an additional layer of protection.