Anthracnose fruit rot of pepper

Anthracnose fruit rot of pepper is a plant pathogenic fungus caused by several species in the genus Colletotrichum Among them C. gloeosporioides has the widest host range among solanaceous crops and various biotypes have been reported on hosts. C. acutatum has caused severe fruit and foliar damage to pepper in several tropical regions. C. coccodes is the least aggressive species and is more commonly found in temperate regions. In general, disease symptoms caused by the various species of Colletotrichum are similar and microscopic analysis is necessary to identify species.

Symptoms
All growth stages may be affected, including postharvest stages. Symptoms occur primarily on ripening fruit often where fruit is touching the soil or plant debris. On ripe fruit there are small, sunken circular depressions up to 30mm (1¼in) in diameter. The center of the lesions becomes tan in color while the tissue beneath the lesion is lighter-colored and dotted with many dark-colored fruiting bodies of the fungus that form concentric rings in the lesion. The salmon-colored areas on the surface in the central portions of the lesions consist of large masses of fungus spores. Often multiple lesions form on individual fruit. When disease is severe, lesions may coalesce. In older lesions, black structures called acervuli may be observed.

Green fruit may also be infected but symptoms will not appear until the fruit ripens at harvest time. Such an infection is called latent. Young fruit infected by C. acutatum can have visible symptom development. Foliage and stem symptoms appear as small, irregularly shaped gray-brown spots with dark brown edges.

Prevention
Plant only seed from disease-free plants or seed treated to reduce any fungal populations. Seed can be disinfested with a 30-minute soak at 52°C. Use only transplants free of disease symptoms. Peppers should be rotated out of infested fields for at least three years. Fields should be planted with crops other than Cucurbits and also tomatoes, aubergine, or other solanaceous crops or strawberries, which are also hosts of C. acutatum. Apply overhead irrigation during the early part of the day so that plants can dry before sundown. In areas where market constraints and other diseases do not limit the choice of cultivar, cultivars demonstrating a moderate level of resistance should be chosen. Apply protective fungicides at flowering when environmental conditions are favorable for disease development. Rates and timing of all further applications should be done according to product label instructions.