Acid Lime Diseases
Scab
Symptoms
Symptoms on Leaves:
- Raised Lesions: The most noticeable symptom on leaves is the presence of small, raised, corky lesions that are pale yellow to gray-brown. These lesions are often irregular in shape and can vary in size.
- Distorted Leaves: Infected leaves may become distorted or twisted, especially if they are infected while still young and developing.
- Scabby Appearance: As the lesions age, they become more scabby and wart-like, giving the leaves a rough texture.
Symptoms on Fruit:
- Scabby Lesions: Fruit lesions are similar to those on leaves—raised, corky, and pale yellow to brown. They often appear as irregular, wart-like protrusions on the fruit’s surface.
- Deformed Fruit: Severe infections can lead to fruit deformation and cracking. The scab lesions do not usually penetrate deeply into the fruit but can cause surface blemishes that reduce marketability.
- Location of Lesions: Lesions are more common on the windward side of the fruit, where rain splash and wind can spread fungal spores.
Symptoms on Twigs:
- Scabby Lesions on Young Twigs: The twigs can develop similar scabby lesions, which may cause twig dieback if the infection is severe.
Management
- Pruning and Sanitation: Prune out and destroy infected twigs and branches to reduce the source of fungal spores. Remove fallen leaves and fruit from the orchard floor to minimize the spread of the fungus.
- Improve Air Circulation: Ensure proper spacing of trees and prune to improve air circulation within the canopy, reducing humidity levels and leaf wetness duration, which can help reduce fungal infection.
- Fungicides should be applied before the onset of wet, humid conditions that favor fungal spread. The first application is typically made when new growth flushes begin, and subsequent applications are timed based on weather conditions and infection pressure.
|
Fungicide |
Dosage |
|---|---|
|
1 ml/ltr |
|
|
1 ml/ltr |
|
|
2 gm/lit |
|
|
2 gm/lit |
