“Peach moniliosis” is another term for a disease commonly known as peach brown rot, caused by the fungus Monilinia fructicola. This fungal disease affects peach trees and other stone fruit trees, causing significant losses in fruit production if not properly managed. Here’s an overview of peach brown rot, its symptoms, recommendations, causes, and preventive measures:
Symptoms:
- Fruit Symptoms:
- Initially, small, water-soaked spots develop on ripe or ripening peaches, usually near the blossom end.
- The infected spots rapidly expand, turning brown and becoming sunken and covered in a grayish-brown moldy growth.
- Infected fruit may become mummified and remain attached to the tree or drop prematurely.
- Blossom and Twig Symptoms:
- In addition to fruit, Monilinia fructicola can infect blossoms and twigs, causing blossom blight and twig dieback.
- Infected blossoms turn brown and may remain attached to the tree, while infected twigs develop cankers and dieback.
Recommendations:
- Cultural Practices:
- Pruning: Prune peach trees to improve air circulation and sunlight penetration into the canopy, which can help reduce humidity and minimize disease development.
- Thinning: Thin peach fruit to reduce overcrowding and promote rapid drying of the fruit surface after rainfall or irrigation.
- Removal of Mummies: Remove and destroy any mummified fruit or infected plant debris from the orchard to reduce inoculum levels.
- Chemical Control:
- Apply fungicides labeled for brown rot control according to recommended schedules, particularly during critical periods such as bloom and fruit ripening.
- Rotate between fungicide groups with different modes of action to reduce the risk of resistance development in Monilinia fructicola populations.
Causes:
- Fungal Pathogen: Peach brown rot is caused by the fungus Monilinia fructicola.
- Environmental Conditions: The fungus thrives in warm, humid conditions. Rain, dew, and high humidity create favorable conditions for spore germination and disease development.
- Infection Sources: Monilinia fructicola can overwinter on infected fruit mummies, twigs, and other plant debris in the orchard, providing a source of inoculum for new infections.
Preventive Measures:
- Sanitation: Remove and destroy infected fruit, mummified fruit, and infected plant debris from the orchard to reduce inoculum levels and disease spread.
- Resistant Varieties: Plant peach varieties that are bred for resistance or tolerance to brown rot, although complete resistance may not be available in all regions.
- Irrigation Management: Avoid overhead irrigation, which can promote disease spread by creating favorable conditions for fungal growth on foliage and fruit.
- Integrated Pest Management (IPM): Incorporate cultural practices, chemical control, and resistant varieties into an integrated pest management program to effectively manage peach brown rot while minimizing environmental impact and pesticide use.
By implementing these preventive measures and adopting an integrated approach to disease management, peach growers can mitigate the impact of brown rot and sustain healthy peach production.