Brown spot of Passionfruit

Alternaria passiflorae

Causal Agent: Brown spot of passionfruit is typically caused by a fungal pathogen, and one of the common culprits is often identified as Alternaria passiflorae.

Symptoms:

  1. Leaf Lesions:

    • Presence of small, dark brown to black lesions on the leaves.
    • Lesions may start as small spots and enlarge over time.

  2. Lesion Appearance:

    • Lesions often have a concentric or target-like appearance.

  3. Leaf Yellowing:

    • Yellowing of the tissue surrounding the lesions.

  4. Fruit Symptoms:

    • In some cases, the pathogen may also affect the fruit, causing dark spots or lesions.

Conditions Favoring Disease:

  1. Humid Conditions:

    • Fungal diseases like Alternaria thrive in humid environments.

  2. Warm Temperatures:

    • Moderate to warm temperatures are conducive to disease development.

Management:

  1. Fungicides:

    • Application of fungicides, especially those effective against Alternaria species, can help manage the disease.

  2. Pruning and Sanitation:

    • Prune affected plant parts to improve air circulation.
    • Remove and destroy infected leaves and debris to reduce the source of inoculum.

  3. Cultural Practices:

    • Proper spacing and planting practices to enhance air circulation.
    • Avoid overhead irrigation to minimize leaf wetness.

  4. Resistant Varieties:

    • Consider planting passionfruit varieties that may show some level of resistance to brown spot.

Note: Brown spot can affect the overall health of passionfruit plants and impact fruit quality. Integrated disease management, combining cultural practices, fungicide applications, and plant hygiene, is essential for effective control.