Rust disease is a common fungal disease that affects a wide variety of plants, from vegetables and fruits to trees and shrubs. It is caused by a group of fungi called rust fungi, which get their name from the rusty-colored spores they produce. Guava rust, caused by the fungus Puccinia psidii, is a serious disease that can affect all parts of the guava tree, including the leaves, shoots, flowers, and fruits. It is a major problem in guava-growing regions around the world, and can cause significant yield losses.
- Type of Infestation: Disease
- Common Name: Guava Rust
- Causal Organism: Puccinia psidii
- Affected Parts Of the plant: Leaves, Shoot, Flowers, Fruits
Environmental favorable factors for pests/Diseases:
- Temperature: 18-25°C (64-77°F). Warmer temperatures can speed up fungal growth but also reduce spore survival.
- Humidity: Creates ideal conditions for spore germination and infection, usually above 80%. Morning dew or frequent rainfall can be detrimental.
Symptoms of Pest/Disease:
Leaves: Small, round, brown or yellow spots that grow in size and develop a raised, yellow border. The centers of the spots may become necrotic and fall out, giving the leaves a ragged appearance.
Shoots: Brown or black lesions that can girdle the stem, stunting growth and causing dieback.
Flowers: Infected flowers may fail to open or may be discolored and stunted.
Fruits: Small, brown or yellow spots that grow in size and become sunken. The affected areas may become cracked and open, exposing the seeds. Severely infected fruits may drop prematurely.
Measures to control Pests/Diseases:
| Products | Technical Names | Dosages |
| DR BLIGHT | Metalaxyl-M 3.3% + Chlorothalonil 33.1% SC | 300-400 ml/acre |
| K ZEB | Mancozeb 75% WP | 500gm per Acre |
| Boost | Propiconazole 25 % EC | 200-300 ml per acre |
