Anthracnose
Apiognomonia veneta
What is Anthracnose (Apiognomonia veneta)?
Anthracnose, caused by the fungus Apiognomonia veneta is a plant disease that affects various tree species. It is distributed in regions with suitable environmental conditions, particularly where prolonged spring rains or foggy conditions occur. Infected plants show symptoms such as brown blotches or irregular spots on leaves, often following the major leaf veins. Shoot terminals and entire leaves or groups of leaves can be killed. Anthracnose does not generally cause serious harm, except in cases of repeated defoliation and extensive branch dieback.
How does Anthracnose (Apiognomonia veneta) occur?
Anthracnose is reproduced through the production and spread of spores by the fungus Apiognomonia veneta. The fungus overwinters primarily in cankers and lesions on infected twigs. When infected tissue becomes wet, spores are produced and spread through splashing water and windborne rain to infect new twigs and foliage. The disease cycle continues if there is new growth and favourable wet conditions. Once foliage matures and the weather becomes warm and dry, disease development slows or stops.
Symptoms
1 - Impacts on Plants
• Anthracnose can cause repeated defoliation in susceptible plants, leading to reduced photosynthesis and overall plant health. • Prolonged or severe Anthracnose infections can weaken plants, making them more susceptible to other diseases or environmental stressors.
2 - Impact on Soil and the Environment
• The loss of infected leaves and twigs, if not properly managed, can contribute to nutrient imbalances in the soil and affect the breakdown of organic matter in the soil. • Anthracnose can impact certain tree species, leading to reduced diversity within ecosystems that rely on those trees.
Solutions
1 - Prevention
• Choose resistant or less susceptible plant varieties when possible. • Ensure adequate spacing between plants for good air circulation and sunlight penetration. • Regularly prune and remove infected twigs and branches, especially during fall or winter. • Rake and dispose of fallen leaves and debris to reduce overwintering sources of infection. • Avoid overhead irrigation that keeps plants wet for extended periods, as it promotes disease. • Maintain proper plant nutrition to enhance overall plant health and resistance.
2 - Treatment
• Apply fungicides according to label instructions, especially during bud swell and bud cap break, repeating if necessary. • Use copper-based fungicides as they can help control Anthracnose. Remember to carefully read and follow the instructions on fungicide labels and consider the specific needs and regulations of your region. • Consider trunk injections with appropriate fungicides for more severe cases, following label instructions. • Seek advice from local experts or extension services for specific treatment recommendations and guidance.
