Powdery mildew of Mangoes

Oidium mangiferae:

Oidium mangiferae, commonly known as mango powdery mildew, is a fungal pathogen that affects mango trees (Mangifera indica). This disease can lead to reduced fruit quality and yield if not properly managed. Here's an informative description of Oidium mangiferae, including its appearance, identification, and management:

Appearance:

Leaf and Shoot Symptoms:

1. White Powdery Growth: The most characteristic symptom is the presence of a white, powdery growth on the surfaces of leaves, young shoots, and inflorescences.
2. Circular Patches: The powdery growth forms circular patches that can coalesce and cover large areas of the affected plant.
3. Leaf Curling: Infected leaves may exhibit curling, distortion, and reduced expansion.
4. Reduced Photosynthesis: Severe infections can lead to reduced photosynthesis and overall plant vigor.

Inflorescence and Fruit Symptoms:

1. Flower Infections: Powdery mildew can affect inflorescences, leading to flower distortion and reduced fruit set.
2. Fruit Infections: The pathogen can also affect developing fruit, leading to a powdery coating on the surface.
3. Reduced Fruit Quality: Infected mangoes may experience reduced quality, affecting flavor and marketability.

Identification:

1. White Powdery Growth: Easily identify mango powdery mildew by the presence of the characteristic white powdery growth on leaves, shoots, flowers, and fruit.
2. Circular Patches: Observe for circular patches of powdery mildew on the upper surface of leaves and other plant parts.
3. Leaf Curling and Distortion: Note any leaf curling, distortion, or yellowing associated with the powdery growth.

Management:

Cultural Practices:

1. Pruning: Prune mango trees to improve air circulation and reduce humidity, minimizing conditions conducive to powdery mildew development.
2. Spacing: Ensure proper tree spacing to promote good air circulation within the canopy.

Resistant Varieties:

1. Plant Resistant Mango Varieties: Utilize mango varieties that are bred for resistance or tolerance to powdery mildew.

Fungicide Application:

1. Regular Sprays: Apply fungicides preventatively and regularly, especially during critical periods of mango growth.
2. Systemic Fungicides: Consider using systemic fungicides that can provide protection to new plant growth.

Sanitation:

1. Remove Infected Debris: Collect and destroy infected leaves, shoots, and fruit to reduce the overwintering source of the pathogen.

Regular Monitoring:

1. Scouting for Symptoms: Regularly monitor mango trees for early symptoms of powdery mildew, especially during periods conducive to disease development.