Pestalotiopsis mangiferae

The fungus reproduces through conidia, which are produced in acervuli. These spores are characterized by their multi-celled structure with distinctive appendages, allowing them to effectively disperse via rain splashes and wind currents.

It exists as a saprophyte on plant debris and as a parasite on living tissues. The pathogen survives during unfavorable weather conditions in the form of dormant mycelium or spores located on infected leaves or twigs.

Taxonomically, it belongs to the family Pestalotiopsidaceae. Identification in the field relies on visual symptom recognition, while laboratory confirmation involves morphological analysis of conidia under a microscope.

Development is highly dependent on environmental factors, specifically high relative humidity and temperatures ranging from 25°C to 30°C, which are optimal for germination and infection processes.

The primary host for this pathogen is the mango tree (Mangifera indica). The fungus attacks almost every aerial part of the plant, including leaves, stems, flowers, and fruits, leading to significant yield losses.

Leaf infection typically manifests as localized necrosis, which disrupts photosynthesis. Severe infections result in massive leaf drop, weakening the tree's overall vigor and capacity to produce fruit.

Fruit damage is the most commercially critical aspect. Infection causes unsightly necrotic lesions that quickly evolve into soft rot, rendering the produce unacceptable for export or local markets.

In young orchards, the fungus can cause dieback of shoots, which severely stunts plant growth. If left unchecked, the accumulation of inoculum in the orchard can lead to yearly recurring outbreaks.

Economic impact is significant, as growers must invest heavily in chemical control and sanitation protocols to maintain orchard health and meet stringent quality standards for fruit exports.

Initial signs consist of small, circular, light-brown spots on leaf surfaces. Over time, these spots expand, often merging into larger patches with a dark, defined margin.

The presence of acervuli is a hallmark of this disease. These appear as tiny, dark, raised dots in the center of necrotic lesions, eventually erupting to release masses of spores.

Fruit infections are characterized by small, slightly sunken spots on the peel. As the fruit ripens, these lesions enlarge rapidly, turning dark brown or black and softening the underlying flesh.

Blossom blight is another critical sign, where infected inflorescences turn black, wither, and fail to develop into fruits. This can result in a total loss of the harvest for that specific season.

Bark cracking and localized exudations may occur on infected stems, indicating that the fungus has colonized the woody tissue and is causing internal structural damage.

Integrated Pest Management (IPM) is essential for controlling Pestalotiopsis mangiferae. The first step involves rigorous orchard sanitation, including the removal and destruction of all infected plant materials.

Chemical control focuses on the application of fungicides. Copper-based sprays are often effective as a preventive measure, while systemic fungicides like triazoles are utilized during periods of high infection risk.

Cultural practices, such as proper pruning, improve air circulation and light penetration within the canopy. Lowering the humidity around the leaves significantly inhibits spore germination.

Post-harvest management is crucial. Minimizing mechanical damage during harvest and storing fruit under controlled temperatures reduces the rate at which latent infections develop into active rot.

• Use of disease-free planting material to avoid introducing the pathogen.
• Balanced nutrient management to improve overall tree resistance.
• Routine cleaning of pruning tools to prevent cross-contamination between trees.