The Mango Grey Blight Disease is an important fungal disease caused by the fungus Pestalotia mangiferae. It is one of the most destructive diseases of mango and has caused significant losses in commercial and backyard mango production. The fungus can spread quickly in an orchard through the wind, rain, contaminated tools, equipment, and clothing and infect nearby trees. Cultural practices such as pruning and cleaning up debris from the orchard can help reduce the spread of the disease.
Chemical treatments and biological control measures can also reduce the severity of mango grey blight disease. To effectively manage this disease, it is important to understand its disease cycle, the mode of disease spread, and the best methods for controlling it. This article will provide an overview and discussion of the Mango Grey Blight Disease in Mango crops, including its symptoms, identification techniques, and control.
Mango Grey Blight Disease Management
The Causal Organism of Mango Grey Blight Disease
- Pestalotia mangiferae is an obligate parasite that belongs to the Family Sporocadaceae of Order Xylariales of the Phylum Ascomycota.
- The pathogen is found in the soil, decaying plant material, and other organic matter.
- The acervuli are tiny black spots on the affected plant parts.
- The conidia are small, yellowish-brown to greyish-brown, globose to cylindrical, smooth-walled ascospores released into the air and spread the disease.
The Disease Cycle of Mango Grey Blight Disease
The disease cycle of the Mango Grey Blight Disease, Pestalotia mangiferae, in Mango Crops, begins when the fungus overwinters in infected plant debris, such as leaves and stems, on the ground or in the soil. The fungus penetrates the healthy tissue of the mango tree and produces haustoria, which are structures that absorb nutrients from the tissue. This causes the infected tissue to become grey and die.
During the spring, when the weather warms up, the fungus produces black, oval-shaped, spore-forming structures containing the fungal spores. These spores are then spread by wind and water to the leaves and stems of healthy mango plants. The spores then infect the leaves and stem, causing discoloration and spots.
The infected leaves and stems develop black or grey spots with yellow margins. These spots become larger and eventually spread over the entire leaf. The leaves eventually become dry and brittle and fall off the plant. The fungus then produces more spores that spread to other parts of the plant and nearby plants. This cycle continues until the entire mango crop is infected.
Occurrence of Mango Grey Blight Disease in Mango Crop
- Location of Mango Grey Blight disease: This disease occurs in mango crops in India, Africa, Bangladesh, Sri Lanka, Nepal, Vietnam, Thailand, Malaysia, Indonesia, the Philippines, the United States, Mexico, Brazil, and Australia.
- Host range: The most common crops affected by Pestalotia mangiferae are mango, oranges, papayas, guavas, bananas, tomatoes, and squash.
Favorable Conditions for Mango Grey Blight Disease Spread in the Field
- Hot, humid conditions favor the disease, which is most severe during rainy seasons.
- The temperature range of 20-25°C and high humidity levels, over 85%, are optimal for the germination of the spores.
- The presence of clouds or fog can increase the humidity levels and reduce the evaporation rate, allowing the infection to thrive.
- Poor crop management practices, such as over-fertilizing, pruning, and irrigation, can cause the crop to become weakened and more susceptible to the disease.
- Insects, such as aphids, can act as vectors and spread the disease from one plant to another.
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