Dothiorella reniformis

Dothiorella reniformis is a fungal pathogen responsible for localized necrosis and stem canker diseases in various plant species. It belongs to the order Botryosphaeriales and is known for its ability to colonize host tissues by infiltrating the bark and cambium, ultimately causing obstruction of the vascular system.

The host range of this fungus primarily includes woody plants, shrubs, and ornamental trees. While it can exist as an endophyte, it becomes pathogenic under stress conditions such as drought, frost damage, or nutrient deficiency. Seedlings and young trees are particularly vulnerable to stem colonization, which can lead to significant structural damage.

Symptoms of the disease are typically observed on branches and stems. Initially, small discolored lesions appear on the bark, which later develop into distinct, kidney-shaped fruiting bodies known as pycnidia. As the infection progresses, the bark cracks, and the underlying wood shows dark necrotic zones. Foliar wilting often follows due to the restricted water flow caused by the fungal hyphae.

Disease development is highly dependent on environmental humidity and temperature. Fungal spores are disseminated by rain splashes, wind, and movement of infested plant material. High humidity levels, common during spring and autumn, promote the germination of conidia and the rapid spread of the pathogen across the plantation or orchard.

Managing Dothiorella reniformis requires an integrated approach to plant health.

• Sanitary pruning of infected branches is crucial to reduce the inoculum load.
• Sterilization of pruning tools is necessary to prevent mechanical transmission.
• Chemical control with copper-based or systemic fungicides during the early growth stage helps in protecting vulnerable tissues.
• Improving overall plant vigor through proper irrigation and balanced fertilization is essential for natural defense.